ucum.xml

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--><spec xmlns:u="http://aurora.regenstrief.org/UCUM"><header><title>The Unified Code for Units of Measure</title><version>2.2</version><revision>N/A</revision><date>2024-06-17</date><authlist><author><name>Gunther Schadow</name><affiliation>Pragmatic Data LLC</affiliation><email href="gschadow@pragmaticdata.com"/></author><author><name>Clement J. McDonald</name><affiliation>National Library of Medicine, Lister Hill</affiliation><email href="cmcdonald@regenstrief.org"/></author></authlist><copyright>1998-2024, Regenstrief Institute, Inc. and the UCUM Organization. All rights reserved.</copyright></header><body><div1 id="section-introduction"><head>Introduction</head><p><emph>The Unified Code for Units of Measure</emph> is a code system intended to include <emph>all</emph> units of
        measures being contemporarily used in international science,
        engineering, and business. The purpose is to facilitate unambiguous
        electronic communication of quantities together with their units. The
        focus is on electronic communication, as opposed to communication
        between humans. A typical application of <emph>The Unified Code for Units of Measure</emph> are electronic data
        interchange (EDI) protocols, but there is nothing that prevents it
        from being used in other types of machine communication.
      </p><p><emph>The Unified Code for Units of Measure</emph> is inspired by and heavily based on ISO&nbsp;2955-1983, ANSI
        X3.50-1986, and HL7's extensions called &ldquo;ISO+&rdquo;. The
        respective ISO and ANSI standards are both entitled
        &ldquo;Representation of [...]  units in systems with limited
        character sets&rdquo; where ISO&nbsp;2955 refers to SI and other units
        provided by ISO&nbsp;1000-1981, while ANSI X3.50 extends ISO&nbsp;2955 to
        include U.S. customary units. Because these standards carry the
        restriction of &ldquo;limited character sets&rdquo; in their names
        they seem to be of less value today, when graphical user interfaces and
        laser printers are in wide-spread use. For this reason, the European
        standard ENV&nbsp;12435 in its clause 7.3 declares ISO&nbsp;2955 obsolete.
      </p><p>
        ENV&nbsp;12435 is dedicated exclusively to the communication of
        measurements between humans in display and print, and does not provide
        codes that can be used in communication between systems. It does not
        even provide a specification that would allow communication of units
        from one system to the screen or printer of another system. The issue
        about displaying units in the common style defined by the 9th
        <emph>Conf&eacute;rence G&eacute;n&eacute;rale des Poids et Mesures</emph>
        (CGPM) in 1947 is not just the character set. Although the
        <emph>Unicode</emph> standard and its predecessor ISO/IEC&nbsp;10646 is
        the richest character set ever, it is still not enough to specify the
        presentation of units, because there are important typographical
        details such as superscripts, subscripts, roman and
        italics.<footnote><p>
            Interestingly the authors of ENV&nbsp;12435 forgot to include
            superscripts in the minimum requirements as given by subclause 7.1.4
            for which they do not specify an alternative.
          </p></footnote></p><p>
        The real value of the restriction on the character set and
        typographical details, however, is not to cope with legacy systems and
        less powerful technology, but to facilitate unambiguous communication
        and interpretation of the meaning of units from one computer system to
        another. In this respect, ISO&nbsp;2955 and ANSI X3.50 are not
        obsolete because there is no other standard that would fill in for
        inter-systems communication of units. However, ISO&nbsp;2599 and ANSI
        X3.50 currently have severe defects:
      </p><list role="ordered"><item><p>
            ISO&nbsp;2955 and ANSI&nbsp;X3.50 contain numerous name conflicts,
            both direct conflicts (e.g., &ldquo;<code>a</code>&rdquo; being used
            for both &ldquo;year&rdquo; and &ldquo;are&rdquo;) and conflicts
            that are generated through combination of unit symbols with prefixes
            (e.g., &ldquo;<code>cd</code>&rdquo; means candela and centi-day and
            &ldquo;<code>PEV</code>&rdquo; means peta-volt and pico-electronvolt.)
          </p></item><item><p>
            Neither ISO&nbsp;2955 nor ANSI&nbsp;X3.50 cover all units that are
            currently used in practice. There are many more units in use than what
            is allowed by the <emph>Syst&egrave;me International
              d'Unit&eacute;s</emph> (SI) and accompanying standards. For example,
            the older CGM-units dyne and erg are still used in the science of
            physiology. Although ANSI&nbsp;X3.50 extends ISO&nbsp;2955 with some
            U.S. customary units, it is still not complete in this respect. For
            example it does not define the degree Fahrenheit.
          </p></item><item><p>
            ANSI&nbsp;X3.50 is semantically ambiguous with respect to customary
            units, even if we do not consider the history and international
            aspects of customary units. Three systems of mass units are used in
            the U.S., avoirdupois used generally, apothecaries' used by
            pharmacists, and troy used in trade with Gold and other precious
            metals. ANSI&nbsp;X3.50 has no way to select any one of those
            specifically, which is bad in medicine, where both apothecaries' and
            avoirdupois weights are being used frequently.
          </p></item></list><p>
        ISO&nbsp;2955 and all standards that do only look for the resolutions
        and recommendations of the CGPM and the <emph>Comit&eacute;
          International des Poids et Mesures</emph> (CIPM) as published by the
        <emph>Bureau International des Poids et Mesures</emph> (BIPM) and various
        ISO standards (ISO&nbsp;1000 and ISO&nbsp;31) fail to recognize that
        the needs in practice are often different from the ideal propositions
        of the CGPM. Although not allowed by the CGPM and related ISO
        standards, many other units are used in international sciences,
        healthcare, engineering, and business, both meaningfully and some
        units of questionable meaning. A coding system that is to be useful in
        practice must cover the requirements and habits of the
        practice&mdash;even some of the bad habits.
      </p><p>
        None of the current standards attempt to specify a semantics of units
        that can be deployed in information systems with moderate
        requirements. Metrological standards such as those published by the
        BIPM are dedicated to maximal scientific correctness of reproducible
        definitions of units. These definitions make sense only to human
        specialists and can hardly be deployed to their full extent by any
        information system that is not dedicated to metrology. On the other
        hand, ISO&nbsp;2955 and ANSI&nbsp;X3.50 provide no semantics at all for the
        codes they define.
      </p><p><emph>The Unified Code for Units of Measure</emph> provides a single coding system for units that is complete,
        free of all ambiguities, and that assigns to each defined unit a
        concise semantics. In communication it is not only important that all
        communicating parties have the same repertoire of symbols, but also that
        all attach the same meaning to the symbols they exchange. The common
        meaning must be computationally verifiable. <emph>The Unified Code for Units of Measure</emph> assumes a
        semantics for units based on dimensional analysis.<footnote><p>
            A more extensive introduction into this semantics of units can be
            found in: Schadow G, McDonald CJ et al: Units of Measure in Clinical
            Information Systems; <it>JAMIA</it> 6(2); Mar/Apr 1999;
            p.&nbsp;151&ndash;162.
          </p></footnote></p><p><!-- FIXME this paragraph is a lump: we need Roadmap, scope, etc. -->
        In short, each unit is defined relative to a system of base units by a
        numeric factor and a vector of exponents by which the base units
        contribute to the unit to be defined. Although we can reflect all the
        meaning of units covered by dimensional analysis with this vector
        notation, the following tables do not show these vectors. One reason
        is that the vectors depend on the base system chosen and even on the
        ordering of the base units. The other reason is that these vectors are
        hard to understand to human readers while they can be easily derived
        computationally. Therefore we define new unit symbols using algebraic
        terms of other units. Those algebraic terms are also valid codes of
        <emph>The Unified Code for Units of Measure</emph>.
      </p></div1><div1><head>Grammar of Units and Unit Terms</head><p name="preliminaries"><emph role="strong"><anchor id="para-1">&sect;1</anchor> preliminaries</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph><emph>The Unified Code for Units of Measure</emph> consists of a basic set of terminal symbols for units, called
          <emph>atomic unit symbols</emph> or <emph>unit atoms</emph>, and multiplier
          prefixes. It also consists of an expression syntax by which these
          symbols can be combined to yield valid units.
        &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
          The tables of terminal symbols are fixed as of every revision of
          <emph>The Unified Code for Units of Measure</emph>, additions, deletions or changes are <emph>not</emph> allowed.
        &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
          All expression that can be derived from these terminal symbols and the
          expression syntax are valid codes. Any expression of <emph>The Unified Code for Units of Measure</emph> has a
          precisely defined semantics.
        </p><comment><p class="comment">
          The expression syntax of <emph>The Unified Code for Units of Measure</emph> generates an infinite number of codes
          with the consequence that it is impossible to compile a table of all
          valid units.
        </p><p class="comment">
          That the tables of terminal symbols may not be extended does not mean
          that missing symbols will never be available in <emph>The Unified Code for Units of Measure</emph>. Suggestions
          for additions of new symbols are welcome and revisions of
          <emph>The Unified Code for Units of Measure</emph> will be released as soon as a change request has been approved.
        </p></comment><p name="full and limited conformance"><emph role="strong"><anchor id="para-2">&sect;2</anchor> full and limited conformance</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph> 
          The semantics of <emph>The Unified Code for Units of Measure</emph> implies equivalence classes such that
          different expressions may have the same meaning.
        &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph> 
          Programs that declare <emph>full conformance</emph> with <emph>The Unified Code for Units of Measure</emph> must
          compare unit expressions by their semantics, i.e. they must detect
          equivalence for different expressions with the same meaning.
        &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
          Programs with <emph>limited conformance</emph> may compare unit expressions
          literally and thus may not detect equivalence of unit expressions.
        </p><comment><p class="comment">
          The option for &ldquo;limited conformance&rdquo; allows <emph>The Unified Code for Units of Measure</emph> to be adopted
          even by less powerful systems that can not or do not want to deal with
          the full semantics of units. Those systems typically have a table of
          fixed unit expression literals that may be related to other literals
          with fixed conversion factors. Although these systems will have
          difficulties to receive unit expressions from various sources, they
          will at least send out valid expressions of <emph>The Unified Code for Units of Measure</emph>, which is an
          important step towards a commonly used coding scheme for units.
        </p></comment><div2><head>Character Set and Lexical Rules</head><p name="character set"><emph role="strong"><anchor id="para-3">&sect;3</anchor> character set</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph> All expressions of <emph>The Unified Code for Units of Measure</emph> shall be built from characters of
            the 7-bit US-ASCII character set exclusively.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph> Terminal unit symbols can consist of all ASCII characters in
            the range of 33&ndash;126 (0x21&ndash;0x7E) excluding
            
            double quotes (&lsquo;<code>"</code>&rsquo;),
            parentheses (&lsquo;<code>(</code>&rsquo; and &lsquo;<code>)</code>&rsquo;),
            plus sign (&lsquo;<code>+</code>&rsquo;'),
            minus sign (&lsquo;<code>-</code>&rsquo;'),
            period (&lsquo;<code>.</code>&rsquo;'),
            solidus (&lsquo;<code>/</code>&rsquo;'),
            equal sign (&lsquo;<code>=</code>&rsquo;'),
            square brackets (&lsquo;<code>[</code>&rsquo; 
            and &lsquo;<code>]</code>&rsquo;), and
            curly braces (&lsquo;<code>{</code>&rsquo; and &lsquo;<code>}</code>&rsquo;),
            
            which have special meaning. 
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph> A terminal unit symbol can not consist of only digits
            (&lsquo;<code>0</code>&rsquo;&ndash;&lsquo;<code>9</code>&rsquo;) because
            those digit strings are interpreted as positive integer
            numbers. However, a symbol &ldquo;<code>10*</code>&rdquo; is allowed
            because it ends with a non-digit allowed to be part of a symbol.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;4</emph></emph> For every terminal symbol there is a case insensitive variant
            defined, to be used when there is a risk of upper and lower case to be
            confused. Although upper and lower case can be mixed in case
            insensitive symbols there is no meaning to the case. Case insensitive
            symbols are incompatible to the case sensitive symbols.
          </p><comment><p class="comment">
            The 7-bit US-ASCII character code is the greatest common denominator
            that can be expected to be available in any communication environment.
            Only very few units normally require symbols from the Greek alphabet
            and thus the cost of requiring Unicode does not outweigh the benefit.
            As explained above, the real issue about writing unit terms naturally
            is not the character set but the ability to write subscripts and
            superscripts and distinguish roman letters from italics.
          </p><p class="comment">
            Some computer systems or programming languages still have the
            requirement of case insensitivity and some humans who are not familiar
            with SI units tend to confuse upper and lower case or can not
            interpret the difference in upper and lower case correctly. For this
            reason the case insensitive symbols are defined. Although <emph>The Unified Code for Units of Measure</emph>
            does not encourage use of case insensitive symbols where not
            absolutely necessary, in some circumstances the case insensitive
            representation may be the greatest common denominator. Thus some
            systems that can handle case sensitivity may end up using case
            insensitive symbols in order to communicate with less powerful
            systems.
          </p><p class="comment">
            ISO&nbsp;2955 and ANSI&nbsp;X3.50 call case sensitive symbols &ldquo;mixed
            case&rdquo; and case insensitive symbols &ldquo;single case&rdquo; and
            list two columns for &ldquo;single case&rdquo; symbols, one for upper
            case and one for lower case.  In <emph>The Unified Code for Units of Measure</emph> all units can be written in
            mixed upper and lower case, but in the case insensitive variant the
            mixing of case does not matter.
          </p><p class="comment">
            White space is not recognized in a a unit term and should generally 
            not occur. UCUM implementations may flag whitespace as an error 
            rather than ignore it. Whitespace is not used as a separator of 
            otherwise ambiguous parts of a unit term.
          </p></comment><p name="prefixes"><emph role="strong"><anchor id="para-4">&sect;4</anchor> prefixes</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>Metric units (cf. <termref ref="para-11">&sect;11</termref>) may be
            combinations of a unit symbol with a prefix symbol.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>The unit symbol to be combined with the prefix must not itself
            contain a prefix. Such a prefix-less unit symbol is called <emph>unit
              atom</emph>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>Prefix and atom are connected immediately without any
            delimiter. Separation of an optional prefix from the atom occurs on
            the lexical level by finding a matching combination of an optional
            prefix and a unit atom.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;4</emph></emph> The prefix is the longest leading substring that matches a
            valid prefix where the remainder is a valid metric unit atom. If no
            such prefix can be matched, the unit atom is without prefix and may be
            both metric or non-metric.<emph role="small">[1&ndash;3: ISO&nbsp;1000, 3; ISO&nbsp;2955-1983, 3.7;
            ANSI&nbsp;X3.50-1986, 3.7 (Rule No. 6).]</emph></p><p name="square brackets"><emph role="strong"><anchor id="para-5">&sect;5</anchor> square brackets</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph> Square brackets (&lsquo;<code>[</code>&rsquo; and 
            &lsquo;<code>]</code>&rsquo;) may be part of a
            unit atom at any place but only as matched pairs. Square brackets are
            lexical elements and not separate syntactical tokens. &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph> Within a matching pair of square brackets the full range of
            characters 33&ndash;126 can be used.<footnote><p>
                see the section about style in <termref ref="para-12">&sect;&sect;12ff</termref>, to find out
                how square brackets are actually used. Note, however, that the user
                has no choice about square bracket symbols, as these are fixed in the
                list of atomic unit symbols.
              </p></footnote>&nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph> Square brackets do <emph>not</emph> determine the boundary between
            prefix and unit atom, but they never span the boundary of unit atoms.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;4</emph></emph> 
            Square brackets must not be nested.
          </p><comment><p class="comment">
            For example
            %
            &ldquo;<code>[abc+ef]</code>&rdquo;,
            &ldquo;<code>ab[c+ef]</code>&rdquo;,
            &ldquo;<code>[abc+]ef</code>&rdquo;, and
            &ldquo;<code>ab[c+ef]</code>&rdquo;
            %
            could all be valid symbols if defined in the tables. 
            In &ldquo;<code>ab[c+ef]</code>&rdquo; either
            &ldquo;<code>a</code>&rdquo; or &ldquo;<code>ab</code>&rdquo; 
            could be defined as a prefix, but not &ldquo;<code>ab[c</code>&rdquo;.
          </p><p class="comment">
            Square brackets take on one task of round parentheses in HL7's
            &ldquo;ISO+&rdquo; code, where one use of parentheses is to augment
            unit symbols with suffixes, as in &ldquo;<code>mm(Hg)</code>&rdquo;.
            Another use is to enclose one full unit symbol into parentheses, as
            &ldquo;<code>(ka_u)</code>&rdquo; (for the King-Armstrong unit of
            catalytic amount of phosphatase).  Apparently, in a unit symbol such
            enclosed one is supposed not to expect a prefix. Thus, even if
            &ldquo;<code>a_u</code>&rdquo; would have been defined,
            &ldquo;<code>(ka_u)</code>&rdquo; should not be matched against
            kilo-<code>a_u</code>.
          </p><p class="comment">
            Parentheses, however, were also used for the nesting of terms since
            HL7 version 2.3. At this point it became ambiguous whether parentheses
            are part of the unit symbol or whether they are syntactic tokens. For
            instance, &ldquo;<code>(ka_u)</code>&rdquo; could mean a nested
            &ldquo;<code>ka_u</code>&rdquo; (where &ldquo;<code>k</code>&rdquo;
            could possibly be a prefix), but also the proper symbol
            &ldquo;<code>(ka_u)</code>&rdquo; that happens to have parentheses as
            part of the symbol. <emph>The Unified Code for Units of Measure</emph> uses parentheses for the usual meaning of
            term nesting and uses square brackets where HL7's &ldquo;ISO+&rdquo;
            assumes parentheses to be part of the unit symbol.
          </p></comment><p name="curly braces"><emph role="strong"><anchor id="para-6">&sect;6</anchor> curly braces</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph> The full range of characters 33&ndash;126 can be used within a
            pair of curly braces (&lsquo;<code>{</code>&rsquo; and
            &lsquo;<code>}</code>&rsquo;). The material enclosed in curly braces is
            called <emph>annotation</emph>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph> 
            Annotations do not contribute to the semantics of the unit but are
            meaningless by definition. Therefore, any fully conformant parser must
            discard all annotations. Parsers of limited conformance <emph>should</emph>
            not value annotations in comparison of units.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
            Annotations do, however, signify the end of a unit symbol.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;4</emph></emph> An annotation without a leading symbol implies the default
            unit <unit>1</unit> (the unity).
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;5</emph></emph> 
            Curly braces must not be nested.
          </p><comment><p class="comment">
            Curly braces are here because people want annotations and deeply
            believe that they need annotations. Especially in chemistry and
            biomedical sciences, there are traditional habits to write annotations
            at units or instead of units, such as &ldquo;%vol.&rdquo;,
            &ldquo;RBC&rdquo;, &ldquo;CFU&rdquo;, &ldquo;kg(wet tis.)&rdquo;, or
            &ldquo;mL(total)&rdquo;. These habits are hard to overcome. Any
            attempt of a coding scheme to restrict this perceived expressiveness
            will ultimately result in the coding scheme not being adopted, or just
            &ldquo;half-way&rdquo; adopted (which is as bad as not adopted).
          </p><p class="comment">
            Two alternative responses to this reality exist: either give in to the
            bad habits and blow up of the code with dimension- and meaningless
            unit atoms, or canalize this habit so that it does no harm. <emph>The Unified Code for Units of Measure</emph>
            canalizes this habit using curly braces. Nevertheless we do continuing
            efforts to upgrade doubtful units to genuine units of <emph>The Unified Code for Units of Measure</emph> by
            defining and linking them to the other units as good as
            possible. Thus, &ldquo;<code>g%</code>&rdquo; is a valid metric unit
            atom (so that &ldquo;<code>mg%</code>&rdquo; is a valid unit too.)
            A <emph>drops</emph>, although quite imprecise, is a valid unit of volume
            &ldquo;<code>[drp]</code>&rdquo;. Even HPF and LPF (the so called
            &ldquo;high-&rdquo; and &ldquo;low power field&rdquo; in the
            microscope) have been defined so that at least they relate to each
            other.
          </p></comment></div2><div2><head>Syntax Rules</head><p name="algebraic unit terms"><emph role="strong"><anchor id="para-7">&sect;7</anchor> algebraic unit terms</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph> All units can be combined in an algebraic term using the
            operators for multiplication (period &lsquo;<code>.</code>&lsquo;) and
            division (solidus &lsquo;<code>/</code>&rsquo;). &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph> The multiplication operator is mandatory it must not be
            omitted or replaced by a space. The multiplication operator is a
            strict binary operator that may occur only <emph>between two</emph> unit
            terms. &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph> The division operator can be used as a binary and unary
            operator, i.e. a leading solidus will invert the unit that directly
            follows it. &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;4</emph></emph> Terms are evaluated from left to right with the period and the
            solidus having the same operator precedence. Multiple division
            operators are allowed within one term. <emph role="small">[ISO&nbsp;1000, 4.5.2; ISO&nbsp;2955-1983, 3.3f; ANSI&nbsp;X3.50-1986, 3.3f
            (Rule No. 2f).]</emph></p><comment><p class="comment">
            The use of the period instead of the asterisk
            (&lsquo;<code>*</code>&rsquo;) as a multiplication operator continues a
            tradition codified in ISO&nbsp;1000 and maintained in ISO&nbsp;2955. Because
            floating point numbers may not occur in unit terms the period is not
            ambiguous. A period in a unit term has no other meaning than to be the
            multiplication operator.
          </p><p class="comment">
            Since Resolution 7 of the 9th CGPM in 1948 the myth of ambiguity being
            introduced by more than one solidus lives on and is quoted in all
            standards concerning the writing of SI units. However, when the strict
            left to right rule is followed there is no ambiguity, neither with one
            solidus nor with more than one solidus. However, in human practice we
            find the tendency to assign a lower precedence to the solidus which
            misleads people to write <emph>a</emph>/<emph>b</emph>&middot;<emph>c</emph> when they
            really mean <emph>a</emph>/(<emph>b</emph>&middot;<emph>c</emph>). When this is
            rewritten as <emph>a</emph>/<emph>b</emph>/<emph>c</emph> there is actually less
            ambiguity that in <emph>a</emph>/<emph>b</emph>&middot;<emph>c</emph>. So the real
            source of ambiguity is when a multiplication operator follows a
            solidus, not when there is more than one solidus in a term. Hence, we
            remove the restriction for only one solidus and introduce parentheses
            which may be used to remove any perceived ambiguity.
          </p></comment><p name="integer numbers"><emph role="strong"><anchor id="para-8">&sect;8</anchor> integer numbers</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph> A positive integer number may appear in place of a simple unit
            symbol. &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph> Only a pure string of decimal digits 
            (&lsquo;<code>0</code>&rsquo;&ndash;&lsquo;<code>9</code>&rsquo;)
            is interpreted as a number. If after one or more digits there is any
            non-digit character found that is valid for unit atoms, all the
            characters (including the digits) will be interpreted as a simple unit
            symbol.
          </p><comment><p class="comment">
            For example, the string &ldquo;<code>123</code>&rdquo; is a positive
            integer number while &ldquo;<code>12a</code>&rdquo; is a symbol. 
          </p><p class="comment">
            Note that the period is only used as a multiplication operator, thus
            &ldquo;<code>2.5</code>&rdquo; means 2 &times; 5 and is not equal to 5/2.
          </p></comment><p name="exponents"><emph role="strong"><anchor id="para-9">&sect;9</anchor> exponents</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph> Simple units may be raised to a power. The exponent is an
            integer number and is written immediately behind the unit
            term. Negative exponents must be preceded by a minus sign
            (&lsquo;<code>-</code>&rsquo; positive exponents may be preceded by an
            optional plus sign (&lsquo;<code>+</code>&rsquo;). &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph> If the simple unit raised to a power is a combination of a
            prefix and a unit atom, both are raised to the power, e.g. &ldquo;1
            <code>cm3</code>&rdquo; equals &ldquo;10<emph role="sup">-6</emph><code>m3</code>&rdquo; not &ldquo;10<emph role="sup">-2</emph><code>m3</code>&rdquo;. 
          <emph role="small">[ISO&nbsp;2955-1983, 3.5f; ANSI&nbsp;X3.50-1986, 3.5f (Rule
            No. 4f).]</emph></p><comment><p class="comment">
            ISO&nbsp;2955 and ANSI&nbsp;X3.50 actually do not allow a plus sign leading a
            positive exponent. However, if there can be any perceived ambiguities,
            an explicit leading plus sign may be of help sometimes. <emph>The
              Unified Code for Units of Measures</emph> therefore allows such plus signs
            at exponents. The plus sign on positive exponents can be used to
            delimit exponents from integer numbers used as simple units. Thus,
            <code>2+10</code> means 2<emph role="sup">10</emph> = 1024.
          </p></comment><p name="nested terms"><emph role="strong"><anchor id="para-10">&sect;10</anchor> nested terms</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph> Unit terms with operators may be enclosed in parentheses
            (&lsquo;<code>(</code>&rsquo; and &lsquo;<code>)</code>&rsquo;) and used
            in place of simple units. Normal left-to-right evaluation can be
            overridden with parentheses. &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph> Parenthesized terms are <emph>not</emph> considered unit atoms
            and hence must not be preceded by a prefix. </p><comment><p class="comment">
            Up until revision 1.9 there was a third clause 
            &ldquo;Since a unit term in parenthesis can be used in place of
            a simple unit, an exponent may follow on a closing parenthesis which
            raises the whole term within the parentheses to the power.&rdquo;
            However this feature was inconsistent with any BNF or other syntax
            description ever provided, was never used and seems to have no 
            relevant use case. For this reason this clause has been stricken.
            This is a <emph>tentative</emph> change. Users who have used this 
            feature in the past, should please comment on this deprecation. 
            If we receive indication that this feature was used by anyone, we
            would undo the deprecation. If no comments are received, the 
            deprecation continues to take effect.
          </p></comment><exhibit role="exhibit"><table class="plain" border="0"><tr valign="top"><td>&lt;<emph>sign</emph>&gt;</td><td>::=</td><td>&ldquo;<code>+</code>&rdquo; | &ldquo;<code>-</code>&rdquo;</td></tr><tr valign="top"><td>&lt;<emph>digit</emph>&gt;</td><td>::=</td><td>&ldquo;<code>0</code>&rdquo; | &ldquo;<code>1</code>&rdquo; | &ldquo;<code>2</code>&rdquo; |
                &ldquo;<code>3</code>&rdquo; | &ldquo;<code>4</code>&rdquo; | &ldquo;<code>5</code>&rdquo; | 
                &ldquo;<code>6</code>&rdquo; | &ldquo;<code>7</code>&rdquo; | &ldquo;<code>8</code>&rdquo; | 
                &ldquo;<code>9</code>&rdquo;</td></tr><tr valign="top"><td>&lt;<emph>digits</emph>&gt;</td><td>::=</td><td>&lt;<emph>digit</emph>&gt;&lt;<emph>digits</emph>&gt; 
                | &lt;<emph>digit</emph>&gt;</td></tr><tr valign="top"><td>&lt;<emph>factor</emph>&gt;</td><td>::=</td><td>&lt;<emph>digits</emph>&gt;</td></tr><tr valign="top"><td>&lt;<emph>exponent</emph>&gt;</td><td>::=</td><td>&lt;<emph>sign</emph>&gt;&lt;<emph>digits</emph>&gt; 
                | &lt;<emph>digits</emph>&gt;</td></tr><tr valign="top"><td>&lt;<emph>simple-unit</emph>&gt;</td><td>::=</td><td>&lt;<emph>ATOM-SYMBOL</emph>&gt;<br/>
                | &lt;<emph>PREFIX-SYMBOL</emph>&gt;&lt;<emph>ATOM-SYMBOL[metric]</emph>&gt;</td></tr><tr valign="top"><td>&lt;<emph>annotatable</emph>&gt;</td><td>::=</td><td>&lt;<emph>simple-unit</emph>&gt;&lt;<emph>exponent</emph>&gt;<br/>
                | &lt;<emph>simple-unit</emph>&gt;</td></tr><tr valign="top"><td>&lt;<emph>component</emph>&gt;</td><td>::=</td><td>&lt;<emph>annotatable</emph>&gt;&lt;<emph>annotation</emph>&gt;<br/>
                | &lt;<emph>annotatable</emph>&gt;<br/>
                | &lt;<emph>annotation</emph>&gt;<br/>
                | &lt;<emph>factor</emph>&gt;<br/>
                | &ldquo;<code>(</code>&rdquo;&lt;<emph>term</emph>&gt;&ldquo;<code>)</code>&rdquo;</td></tr><tr valign="top"><td>&lt;<emph>term</emph>&gt;</td><td>::=</td><td>&lt;<emph>term</emph>&gt;&ldquo;<code>.</code>&rdquo;&lt;<emph>component</emph>&gt;<br/>
                | &lt;<emph>term</emph>&gt;&ldquo;<code>/</code>&rdquo;&lt;<emph>component</emph>&gt;<br/>
                | &lt;<emph>component</emph>&gt;</td></tr><tr valign="top"><td>&lt;<emph>main-term</emph>&gt;</td><td>::=</td><td>&ldquo;<code>/</code>&rdquo;&lt;<emph>term</emph>&gt;<br/>
                | &lt;<emph>term</emph>&gt;</td></tr><tr valign="top"><td>&lt;<emph>annotation</emph>&gt;</td><td>::=</td><td>&ldquo;<code>{</code>&rdquo;&lt;<emph>ANNOTATION-STRING</emph>&gt;&ldquo;<code>}</code>&rdquo;</td></tr></table><caption>
            The complete syntax in the Backus-Naur Form.
          </caption></exhibit><graphic source="graphics/https://raw.githubusercontent.com/ucum-org/ucum/main/assets/images/ucum-state-automaton.gif" alt="Pushdown-state automaton describing the syntax."/></div2><div2><head>The Predicate &ldquo;Metric&rdquo;</head><p id="para-metric" name="metric and non-metric unit atoms"><emph role="strong"><anchor id="para-11">&sect;11</anchor> metric and non-metric unit atoms</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph> Only metric unit atoms may be combined with a prefix.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph> To be metric or not to be metric is a predicate assigned to
            each unit atom where that unit atom is defined.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph> All base units are metric. No non-metric unit can be part of
            the basis.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;4</emph></emph> A unit must be a quantity on a ratio scale in order to be
            metric.
          </p><comment><p class="comment">
            The metric predicate accounts for the fact that there are units that
            are prefixed and others that are not. This helps to disambiguate the
            parsing of simple units into prefix and atom.
          </p><p class="comment">
            To determine whether a given unit atom is metric or not is not
            trivial. It is a cultural phenomenon, subject to change, just like
            language, the meaning of words and how words can be used. At one time
            we can clearly tell right or wrong usage of words, but these
            decisions may need to be revised with the passage of time.
          </p><p class="comment">
            Generally, metric units are those defined &ldquo;in the spirit&rdquo;
            of the metric system, that emerged in France of the 18th century and
            was rapidly adopted by scientists. Metric units are usually based on
            reproducible natural phenomena and are usually not part of a system of
            comparable units with different magintudes, especially not if the
            ratios of these units are not powers of 10. Instead, metric units use
            multiplier prefixes that magnify or diminish the value of the unit
            by powers of ten.
          </p><p class="comment">
            Conversely, customary units are in the spirit of the middle age as
            most of them can be traced back into a time around the 10th century,
            some are even older from the Roman and Babylonian empires. Most
            customary units are based on the average size of human anatomical or
            botanic structures (e.g., foot, ell, fathom, grain, rod) and come in
            series of comparable units with ratios 1/2, 1/4, 1/12, 1/16, and
            others. Thus all customary units are non-metric
          </p><p class="comment">
            Not all units from ISO&nbsp;1000 are metric as degree, minute and second of
            plane angle are non-metric as well as minute, hour, day, month, and
            year. The second is a metric unit because it is a part of the SI
            basis, although it used to be part of a series of customary units
            (originating in the Babylonian era).
          </p><p class="comment">
            Furthermore, for a unit to be metric it must be a quantity on a ratio
            scale where multiplication and division with scalars are defined.  The
            <emph>Comit&eacute; Consultatif d'Unit&eacute;s</emph> (CCU) decided
            in February 1995 that SI prefixes may be used with the degree
            Celsius. This statement has not been made explicitly before. This is
            an unfortunate decision because difference-scale units like the degree
            Celsius have no multiplication operation, so that the prefix value
            could be multiplied with the unit. Instead the prefix at non-ratio
            units scales the measurement value. One dekameter is 10 times of a
            meter, but there is no meaning to 10 times of 1&nbsp;&deg;C in the
            same way as 30&nbsp;&deg;C are not 3 times as much as
            10&nbsp;&deg;C. See <termref ref="para-21">&sect;&sect;21ff</termref> on how <emph>The Unified Code for Units of Measure</emph> finds a
            way to accommodate this different use of prefixes at units such as the
            degree Celsius, bel or neper.
          </p></comment></div2><div2><head>Style</head><comment><p class="comment">
            Except for the rule on curly braces (<termref ref="para-12">&sect;12</termref>), the
            rules on style govern the creation of the tables of unit atoms not
            their individual use. Users of <emph>The Unified Code for Units of Measure</emph> need not care about style rules
            (<termref ref="para-13">&sect;&sect;13&ndash;15</termref>) because users
            just use the symbols defined in the tables. Hence, style rules do not
            affect conformance to <emph>The Unified Code for Units of Measure</emph>. New submissions of unit atoms, however,
            must conform to the style rules.
          </p></comment><p id="para-curly" name="curly braces"><emph role="strong"><anchor id="para-12">&sect;12</anchor> curly braces</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph> 
            Curly braces may be used to enclose annotations that are often written
            in place of units or behind units but that do not have a proper
            meaning of a unit and do not change the meaning of a unit. 
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            Annotations have no semantic value.
          </p><comment><p class="comment">
            For example one can write &ldquo;<code>%{vol}</code>&rdquo;,
            &ldquo;<code>kg{total}</code>&rdquo;, or &ldquo;<code>{RBC}</code>&rdquo;
            (for &ldquo;red blood cells&rdquo;) as pseudo-units. However, these
            annotations do not have any effect on the semantics, which is why
            these example expressions are equivalent to
            &ldquo;<code>%</code>&rdquo;, &ldquo;<code>kg</code>&rdquo;, and
            &ldquo;<code>1</code>&rdquo; respectively.
          </p></comment><p id="para-underscore" name="underscore"><emph role="strong"><anchor id="para-13">&sect;13</anchor> underscore</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph> When in print a unit would have a subscript, an underscore
            (&lsquo;<code>_</code>&rsquo;) is used to separate the subscript from
            the stem of the unit symbol. &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            The subscript is part of the unit atom.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph> subscripts are used to disambiguate the two units with the
            same name but different meanings.</p><comment><p class="comment">
            For example when distinguishing the International Table calorie from
            the thermochemical calorie, we would use 1&nbsp;cal<emph role="sub">IT</emph> or
            1&nbsp;cal<emph role="sub">th</emph> in print. <emph>The Unified Code for Units of Measure</emph> defines the symbols
            &ldquo;<code>cal_IT</code>&rdquo; and
            &ldquo;<code>cal_th</code>&rdquo; with the underscore signifying that
            &ldquo;IT&rdquo; and &ldquo;th&rdquo; are subscripts. Other examples
            are the distinctions between the Julian and Gregorian calendar year
            from the tropical year or the British imperial gallon from the U.S.
            gallon (see <termref ref="para-31">&sect;31</termref> and <termref ref="para-37">&sect;&sect;37ff</termref>).
          </p></comment><p name="square brackets"><emph role="strong"><anchor id="para-14">&sect;14</anchor> square brackets</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph> Square brackets enclose suffixes of unit symbols that change
            the meaning of a unit stem.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph> All customary units shall be enclosed completely by square
            brackets.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
            Other unit atoms shall be enclosed in square brackets if they are very
            rare, if they will conflict with other units, or if they are normally
            not used as a unit symbol but do have a proper meaning as a unit in
            <emph>The Unified Code for Units of Measure</emph>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;4</emph></emph>
            Square brackets are part of the unit atom.
          </p><comment><p class="comment">
            For example 1&nbsp;m&nbsp;H<emph role="sub">2</emph>O is written as
            &ldquo;<code>m[H2O]</code>&rdquo; in <emph>The Unified Code for Units of Measure</emph> because the suffix
            H<emph role="sub">2</emph>O changes the meaning of the unit atom for meter (length)
            to a unit of pressure.
          </p><p class="comment">
            Customary units are defined in <emph>The Unified Code for Units of Measure</emph> in order to accommodate
            practical needs. However metric units are still preferred and the
            customary symbols should not interfere with metric symbols in any
            way. Thus, customary units are &ldquo;stigmatized&rdquo; by enclosing
            them into square brackets.
          </p><p class="comment">
            If unit symbols for the purpose of display and print are derived from
            <emph>The Unified Code for Units of Measure</emph> units, the square brackets can be removed. However, display
            units are out of scope of <emph>The Unified Code for Units of Measure</emph>.
          </p></comment><p id="para-apostrophe" name="apostrophe"><emph role="strong"><anchor id="para-15">&sect;15</anchor> apostrophe</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            The apostrophe (&lsquo;<code>'</code>&rsquo;) is used to separate words
            or abbreviated words in a multi-word unit symbol.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            Since units are mathematically defined symbols and not abbreviations
            of words, multi-word unit symbols should be defined only to reflect
            existing habits, not in order to create new ones.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
            Multi-word units should always be enclosed in square brackets.
          </p><comment><p class="comment">
            For example, such legacy units called &ldquo;Bodansky unit&rdquo; or
            &ldquo;Todd unit&rdquo; have the unit symbols
            &ldquo;<code>[bdsk'U]</code>&rdquo;, and
            &ldquo;<code>[todd'U]</code>&rdquo; respectively.
          </p></comment></div2></div1><div1><head>Semantics</head><p name="preliminaries"><emph role="strong"><anchor id="para-16">&sect;16</anchor> preliminaries</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph> The semantics of <emph>The Unified Code for Units of Measure</emph> is defined by the algebraic
          operations of multiplication, division and exponentiation between
          units, by the equivalence relations of equality and commensurability
          of units, and by the multiplication of a unit with a scalar.
        &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph> Every expression in <emph>The Unified Code for Units of Measure</emph> is mapped to one and only one
          semantic element. But every semantic element may have more than one
          valid representant in <emph>The Unified Code for Units of Measure</emph>.
        &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph> 
          The set of expressions in <emph>The Unified Code for Units of Measure</emph> is infinite.
        </p><p name="equality and commensurability"><emph role="strong"><anchor id="para-17">&sect;17</anchor> equality and commensurability</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph> The set of expressions in <emph>The Unified Code for Units of Measure</emph> has two binary, symmetric,
          reflexive, and transitive relations (equivalence relations)
          &ldquo;equals&rdquo; = and &ldquo;is commensurable with&rdquo;
          ~. All expressions that are equal are also commensurable but not
          all commensurable expressions are equal.</p><p name="algebra of units"><emph role="strong"><anchor id="para-18">&sect;18</anchor> algebra of units</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph> The equivalence classes generated by the equality relation =
          are called <emph>units</emph>.
        &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph> The set of units <emph>U</emph> has a binary multiplication operator
          &middot; that is associative and commutative and has the neutral
          element <emph role="strong">1</emph> (so called <emph>the unity</emph>). For each unit
          <emph role="strong">u</emph> &isin; <emph>U</emph> there is an inverse unit
          <emph role="strong">u</emph><emph role="sup">-1</emph> such that <emph role="strong">u</emph> &middot;
          <emph role="strong">u</emph><emph role="sup">-1</emph> = <emph role="strong">1</emph>. Thus, (<emph>U</emph>, &middot;) is
          an Abelian group.
        &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph> The division operation <emph role="strong">u</emph> / <emph role="strong">v</emph> is defined as
          <emph role="strong">u</emph> &middot; <emph role="strong">v</emph><emph role="sup">-1</emph>. &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;4</emph></emph> The exponentiation operation with integer exponents <emph>n</emph>
          is defined as <emph role="strong">u</emph><emph role="sup"><emph>n</emph></emph> = <emph role="strong">&Pi;</emph><emph role="sub">1</emph><emph role="sup">n</emph><emph role="strong">u</emph>. 
        &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;5</emph></emph>
          The product <emph role="strong">u</emph>' = <emph>r</emph><emph role="strong">u</emph> of a real number scalar
          <!-- <v>r</v> &element; \Re --> with the unit <emph role="strong">u</emph> is also a
          unit, where <emph role="strong">u</emph>' ~ <emph role="strong">u</emph>.
        </p><p id="para-dimension" name="dimension and magnitude"><emph role="strong"><anchor id="para-19">&sect;19</anchor> dimension and magnitude</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph> The equivalence classes generated by the commensurability
          relation ~ are called <emph>dimensions</emph>.  The set <emph>D</emph>
          of dimensions is infinite in principle, but only a finite subset of
          dimensions are used in practice. Thus, implementations of <emph>The Unified Code for Units of Measure</emph> need
          not be able to represent the infinite set of dimensions.
        &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
          Two commensurable units that are not equal differ only by their
          magnitude.
        &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph> The quotient <emph role="strong">u</emph> / <emph role="strong">v</emph> of any two commensurable
          units <emph role="strong">u</emph> ~ <emph role="strong">v</emph> is of the same dimension as the
          unity (<emph role="strong">u</emph> / <emph role="strong">v</emph> ~ <emph role="strong">1</emph>). This quotient is
          also equal to the unity multiplied with a scalar <emph>r</emph><!--
               &element; \Re -->: <emph role="strong">u</emph> / <emph role="strong">v</emph> = <emph>r</emph><emph role="strong">1</emph>,
          where <emph>r</emph> is called the <emph>relative magnitude</emph> of
          <emph role="strong">u</emph> regarding <emph role="strong">v</emph>.</p><p name="base units"><emph role="strong"><anchor id="para-20">&sect;20</anchor> base units</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
          Any system of units is constructed from a finite set <emph role="strong">B</emph> of
          mutually independent base units <emph role="strong">B</emph> = {
          <emph role="strong">b</emph><emph role="sub">1</emph>, <emph role="strong">b</emph><emph role="sub">2</emph>, ...,
          <emph role="strong">b</emph><emph role="sub"><emph>n</emph></emph> }, on which any other unit <emph role="strong">u</emph>
          &isin; <emph>U</emph> is defined as <emph role="strong">u</emph> = <emph>r</emph><emph role="sub">1</emph><emph role="strong">b</emph><emph role="sub">1</emph><emph role="sup"><emph>u</emph><emph role="sub">1</emph></emph> &middot;
          <emph>r</emph><emph role="sub">2</emph><emph role="strong">b</emph><emph role="sub">2</emph><emph role="sup"><emph>u</emph><emph role="sub">2</emph></emph> &middot;
          ... &middot; <emph>r</emph><emph role="sub"><emph>n</emph></emph><emph role="strong">b</emph><emph role="sub"><emph>n</emph></emph><emph role="sup"><emph>u</emph><emph role="sub"><emph>n</emph></emph></emph>,
          where <emph>r</emph> = <emph>r</emph><emph role="sub">1</emph> &middot; <emph>r</emph><emph role="sub">2</emph>
          &middot;&middot; &middot; <emph>r</emph><emph role="sub"><emph>n</emph></emph> is called the
          <emph>magnitude</emph> of the unit <emph role="strong">u</emph> regarding <emph role="strong">B</emph>.
        &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
          With respect to a basis <emph role="strong">B</emph> every unit can thus be
          represented as a pair (<emph>r</emph>, <emph>&ucirc;</emph>) of magnitude <emph>r</emph><!-- &element; \Re --> and dimension <emph>&ucirc;</emph> =
          (<emph>u</emph><emph role="sub">1</emph>, <emph>u</emph><emph role="sub">2</emph>, ...,
          <emph>u</emph><emph role="sub"><emph>n</emph></emph>).
        &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
          Two sets of base units are equivalent if there is an isomorphism
          between the sets of units that they generate.
        </p><comment><p class="comment"><termref ref="para-19">&sect;19</termref>.1 allows to limit the set of
          supported dimensions. Most practically used units contain exponents of
          -4 to +4.<!-- wrong: , some may contain -5, such as hemodynamic resistance measured
               traditionally in 1&nbsp;dyn&middot;s/cm<sup>5</sup>.--> Thus if memory is
             limited, 4 bit per component of the dimension vector could be
             sufficient.
           </p></comment><div2><head>Special Units on non-ratio Scales</head><p id="para-special" name="special units"><emph role="strong"><anchor id="para-21">&sect;21</anchor> special units</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            Those symbols that are used as units that imply a measurement on a
            scale other than a ratio scale (e.g., interval scale, logarithmic
            scale) are defined differently. These do not represent proper units as
            elements of the group (<emph>U</emph>,&middot;). Therefore those special
            semantic entities are called <emph>special units</emph>, as opposed to
            <emph>proper units</emph>. The set of special units is denoted
            <emph>S</emph>, where <emph>S</emph> &cap; <emph>U</emph> = {}.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            A special unit <emph role="strong">s</emph> &isin; <emph>S</emph> is defined as
            the triple (<emph role="strong">u</emph>, <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph>,
            <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph><emph role="sup">-1</emph>) where <emph role="strong">u</emph>
            &isin; <emph>U</emph> is the &ldquo;corresponding&rdquo; proper unit of
            <emph role="strong">s</emph> and where <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph> and
            <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph><emph role="sup">-1</emph> are mutually inverse
            real functions converting the measurement value to and from the
            special unit.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
            Although not elements of <emph>U</emph>, special units are said to be
            &ldquo;of the same dimension&rdquo; or &ldquo;commensurable
            with&rdquo; their corresponding proper unit <emph role="strong">u</emph> and the class
            of units commensurable with <emph role="strong">u</emph>. This can be expressed by means
            of a binary, symmetric, transitive and reflexive relation &asymp;
            on <emph>U</emph> &cup; <emph>S</emph>.
          </p><comment><p class="comment">
            The functions <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph> and
            <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph><emph role="sup">-1</emph> are applied as follows: let
            <emph>r</emph><emph role="sub"><emph role="strong">s</emph></emph> be the numeric measurement value
            expressed in the special unit <emph role="strong">s</emph> and let <emph>m</emph> be the
            corresponding dimensioned quantity, i.e., the measurement with proper
            unit <emph role="strong">u</emph>. Now, <emph>r</emph><emph role="sub"><emph role="strong">s</emph></emph> =
            <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph>(<emph>m</emph>/<emph role="strong">u</emph>) converts the proper
            measurement to the special unit and <emph>m</emph> =
            <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph><emph role="sup">-1</emph>(<emph>r</emph><emph role="sub"><emph role="strong">s</emph></emph>)
            &times; <emph role="strong">u</emph> does the inverse.
          </p></comment><p name="operations on special units"><emph role="strong"><anchor id="para-22">&sect;22</anchor> operations on special units</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            In theory, special units cannot take part in any algebraic operations,
            neither involving other units, nor themselves (exponentiation) nor
            involving scalars.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            Special units are therefore non-metric units.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
            However, due to the requirement of the SI that does allow prefixes on
            the degree Celsius, special units may be <emph>scaled</emph> trough a prefix
            or an arbitrary numeric factor.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;4</emph></emph> The scale factor <emph>&alpha;</emph><!-- &element; \Re --> is an
            additional component of the special unit, which in turn is defined by
            a quadruple <emph role="strong">s</emph> = (<emph role="strong">u</emph>, <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph>,
            <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph><emph role="sup">-1</emph>, <emph>&alpha;</emph>). When the
            functions <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph> and
            <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph><emph role="sup">-1</emph> are applied to a measurement value
            <emph>x</emph> to convert to and from the special unit the scale factor is
            applied as follows: <emph>x</emph>' = <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph>(<emph>x</emph>) /
            <emph>&alpha;</emph> converts from <emph>x</emph> expressed in the corresponding
            proper unit to <emph>x</emph>' in terms of the special unit and <emph>x</emph> =
            <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph><emph role="sup">-1</emph>(<emph>&alpha;</emph><emph>x</emph>') does
            the reverse.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;5</emph></emph>
            Multiplication of a special unit <emph role="strong">s</emph> = (<emph role="strong">u</emph>,
            <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph>,
            <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph><emph role="sup">-1</emph>, <emph>&alpha;</emph>) with a
            scalar <emph>&beta;</emph><!-- &element; &Re; --> is defined as
            <emph>&beta;</emph><emph role="strong">s</emph> = (<emph role="strong">u</emph>, <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph>,
            <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph><emph role="sup">-1</emph>, <emph>&beta;</emph><emph>&alpha;</emph>). Multiplication of a special unit <emph role="strong">s</emph> with a
            dimensionless unit <emph>r</emph><emph role="strong">1</emph> is defined as <emph>r</emph><emph role="strong">s</emph>.
          </p><comment><p class="comment">
            Since prefixes have a scalar value that multiplies the unit atom, a
            unit must at least have a defined multiplication operation with a
            scalar in order to be a candidate for the metric predicate. All proper
            units are candidates for the metric property, special units are no
            such candidates.
          </p><p class="comment">
            The <emph>Comit&eacute; Consultatif d'Unit&eacute;s</emph> (CCU)
            decided in February 1995 that any SI prefix may be used with degree
            Celsius. This statement has not been made explicitly before. This is
            an unfortunate decision because difference-scale units like the degree
            Celsius have no multiplication operation, so that the prefix value
            could be multiplied with the unit. Instead the prefix at non-ratio
            units scales the measurement value. One wonders why the CGPM keeps the
            Celsius temperature in the SI as it is superfluous and in a unique way
            incoherent with the SI.
          </p><p class="comment">
            The scale factor <emph>&alpha;</emph> is applied with the functions
            <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph> and <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph><emph role="sup">-1</emph>
            as follows: let <emph>r</emph><emph role="sub"><emph role="strong">s</emph></emph> be the numeric measurement
            value expressed in the special unit <emph role="strong">s</emph> and let <emph>m</emph> be the
            corresponding dimensioned quantity, i.e., the measurement with proper
            unit <emph role="strong">u</emph>. Now, <emph>r</emph><emph role="sub"><emph role="strong">s</emph></emph> =
            <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph>(<emph>m</emph>/<emph role="strong">u</emph>) / <emph>&alpha;</emph>
            converts the proper measurement to the special unit and <emph>m</emph> =
            <emph>f</emph><emph role="sub"><emph role="strong">s</emph></emph><emph role="sup">-1</emph>(<emph>&alpha;</emph><emph>r</emph><emph role="sub"><emph role="strong">s</emph></emph>) &times; <emph role="strong">u</emph> does the reverse.
          </p></comment><p name="definition of special units"><emph role="strong"><anchor id="para-23">&sect;23</anchor> definition of special units</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            Special units are marked in the definition tables for unit atoms by a
            bullet (&lsquo;&bull;&rsquo;) in the column titled &ldquo;value&rdquo;
            and a special expression in the column titled
            &ldquo;definition&rdquo;. The BNF for the special expression is &lt;<emph>special-unit</emph>&gt; ::= &lt;<emph>function-symbol</emph>&gt;&ldquo;<code>(</code>&rdquo;&lt;<emph>floating-point-number</emph>&gt;&ldquo;<code> </code>&rdquo;&lt;<emph>term</emph>&gt;&ldquo;<code>)</code>&rdquo; The function symbols are defined as
            needed.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            Special expressions are <emph>not</emph> valid expressions in <emph>The Unified Code for Units of Measure</emph>,
            they are <emph>only</emph> used for defining special units.
          </p></div2><div2><head>Arbitrary Units</head><p id="para-arbitrary" name="arbitrary units"><emph role="strong"><anchor id="para-24">&sect;24</anchor> arbitrary units</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            Arbitrary or procedure defined units are units whose meaning entirely
            depends on the measurement procedure (assay). These units have no
            general meaning in relation with any other unit in the SI. Therefore those arbitrary
            semantic entities are called <emph>arbitrary units</emph>, as opposed to
            <emph>proper units</emph>. The set of arbitrary units is denoted
            <emph>A</emph>, where <emph>A</emph> &cap; <emph>U</emph> = {}.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            An arbitrary unit has no further definition in the semantic framework of <emph>The Unified Code for Units of Measure</emph>&nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
            Arbitrary units are not &ldquo;of any specific dimension&rdquo; and are
            not &ldquo;commensurable with&rdquo; any other unit.
          </p><comment><p class="comment">
            Until version 1.6 <emph>The Unified Code for Units of Measure</emph> has dealt with arbitrary units as dimensionless,
            but as an effect the semantics of <emph>The Unified Code for Units of Measure</emph> made all arbitrary units 
            commensurable. Since version 1.7 of <emph>The Unified Code for Units of Measure</emph> it is no longer possible to
            convert or compare arbitrary units with any other arbitrary unit.
          </p></comment><p name="operations on arbitrary units"><emph role="strong"><anchor id="para-25">&sect;25</anchor> operations on arbitrary units</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            Any term involving arbitrary units, is itself an arbitrary unit and is not
            comparable with any other arbitrary unit or term.
          </p><p name="definition of arbitrary units"><emph role="strong"><anchor id="para-26">&sect;26</anchor> definition of arbitrary units</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            Arbitrary units are marked in the definition tables for unit atoms by a
            bullet (&lsquo;&bull;&rsquo;) in the column titled &ldquo;value&rdquo;
            and a bullet in the column titled &ldquo;definition&rdquo;.
          </p></div2></div1><div1><head>Tables of Terminal Symbols</head><div2><head>Prefixes</head><p name="prefixes"><emph role="strong"><anchor id="para-27">&sect;27</anchor> prefixes</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            Prefix symbols are those defined in <tabref ref="prefixes"/>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph> There are five columns titled &ldquo;name,&rdquo;
            &ldquo;print,&rdquo; &ldquo;c/s,&rdquo; &ldquo;c/i,&rdquo; and
            &ldquo;value&rdquo; The name is the full (official) name of the
            unit. The official symbol used in print this is listed in the column
            &ldquo;print&rdquo; &ldquo;C/s,&rdquo; and &ldquo;c/i&rdquo; list the
            symbol in the case sensitive and the case insensitive variants
            respectively. &ldquo;Value&rdquo; is the scalar value by which the
            unit atom is multiplied if combined with the prefix.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
            Only the columns titled &ldquo;c/s,&rdquo; &ldquo;c/i,&rdquo; and
            &ldquo;value,&rdquo; are normative. Full name and print symbol are
            defined by the CGPM and are out of scope of <emph>The Unified Code for Units of Measure</emph>.
          </p><comment><p class="comment">
            The case insensitive prefix symbols are slightly different from those
            defined by ISO&nbsp;2955 and ANSI&nbsp;X3.50, where &ldquo;giga-,&rdquo;
            &ldquo;tera-,&rdquo; and &ldquo;peta-&rdquo; have been
            &ldquo;<code>G</code>,&rdquo; &ldquo;<code>T</code>,&rdquo; and
            &ldquo;<code>PE</code>.&rdquo; <emph>The Unified Code for Units of Measure</emph> has a larger set of unit atoms
            and needs to prevent more name conflicts. Tera and giga have a second
            letter to be safe in the future. The change of
            &ldquo;<code>PE</code>&rdquo; to &ldquo;<code>PT</code>&rdquo; would
            be the way to go for ISO&nbsp;2955 which currently has a name conflict
            (among others) with peta-volt and pico-electronvolt.
          </p><p class="comment">
            The new prefixes &ldquo;yotta-,&rdquo; &ldquo;zetta-,&rdquo;
            &ldquo;yocto-,&rdquo; and &ldquo;zepto-&rdquo; that were adopted by
            the 19th CGPM (1990) have a second letter &lsquo;A&rsquo; and
            &lsquo;O&rsquo; resp. to avoid current and future conflicts and to
            disambiguate among themselves. The other submultiples
            &ldquo;micro-&rdquo; to &ldquo;atto-&rdquo; are represented by a
            single letter to keep with the tradition.
          </p></comment><table id="prefixes"><tr><th>name</th><th>print</th><th>c/s</th><th>c/i</th><th>value</th></tr><caption>The prefix symbols</caption><tr><td>yotta&nbsp;</td><td>Y&nbsp;</td><td><code>Y</code></td><td><code>YA</code></td><td>1 &times; 10<emph role="sup">24</emph>&nbsp;</td></tr><tr><td>zetta&nbsp;</td><td>Z&nbsp;</td><td><code>Z</code></td><td><code>ZA</code></td><td>1 &times; 10<emph role="sup">21</emph>&nbsp;</td></tr><tr><td>exa&nbsp;</td><td>E&nbsp;</td><td><code>E</code></td><td><code>EX</code></td><td>1 &times; 10<emph role="sup">18</emph>&nbsp;</td></tr><tr><td>peta&nbsp;</td><td>P&nbsp;</td><td><code>P</code></td><td><code>PT</code></td><td>1 &times; 10<emph role="sup">15</emph>&nbsp;</td></tr><tr><td>tera&nbsp;</td><td>T&nbsp;</td><td><code>T</code></td><td><code>TR</code></td><td>1 &times; 10<emph role="sup">12</emph>&nbsp;</td></tr><tr><td>giga&nbsp;</td><td>G&nbsp;</td><td><code>G</code></td><td><code>GA</code></td><td>1 &times; 10<emph role="sup">9</emph>&nbsp;</td></tr><tr><td>mega&nbsp;</td><td>M&nbsp;</td><td><code>M</code></td><td><code>MA</code></td><td>1 &times; 10<emph role="sup">6</emph>&nbsp;</td></tr><tr><td>kilo&nbsp;</td><td>k&nbsp;</td><td><code>k</code></td><td><code>K</code></td><td>1 &times; 10<emph role="sup">3</emph>&nbsp;</td></tr><tr><td>hecto&nbsp;</td><td>h&nbsp;</td><td><code>h</code></td><td><code>H</code></td><td>1 &times; 10<emph role="sup">2</emph>&nbsp;</td></tr><tr><td>deka&nbsp;</td><td>da&nbsp;</td><td><code>da</code></td><td><code>DA</code></td><td>1 &times; 10<emph role="sup">1</emph>&nbsp;</td></tr><tr><td>deci&nbsp;</td><td>d&nbsp;</td><td><code>d</code></td><td><code>D</code></td><td>1 &times; 10<emph role="sup">-1</emph>&nbsp;</td></tr><tr><td>centi&nbsp;</td><td>c&nbsp;</td><td><code>c</code></td><td><code>C</code></td><td>1 &times; 10<emph role="sup">-2</emph>&nbsp;</td></tr><tr><td>milli&nbsp;</td><td>m&nbsp;</td><td><code>m</code></td><td><code>M</code></td><td>1 &times; 10<emph role="sup">-3</emph>&nbsp;</td></tr><tr><td>micro&nbsp;</td><td>&mu;&nbsp;</td><td><code>u</code></td><td><code>U</code></td><td>1 &times; 10<emph role="sup">-6</emph>&nbsp;</td></tr><tr><td>nano&nbsp;</td><td>n&nbsp;</td><td><code>n</code></td><td><code>N</code></td><td>1 &times; 10<emph role="sup">-9</emph>&nbsp;</td></tr><tr><td>pico&nbsp;</td><td>p&nbsp;</td><td><code>p</code></td><td><code>P</code></td><td>1 &times; 10<emph role="sup">-12</emph>&nbsp;</td></tr><tr><td>femto&nbsp;</td><td>f&nbsp;</td><td><code>f</code></td><td><code>F</code></td><td>1 &times; 10<emph role="sup">-15</emph>&nbsp;</td></tr><tr><td>atto&nbsp;</td><td>a&nbsp;</td><td><code>a</code></td><td><code>A</code></td><td>1 &times; 10<emph role="sup">-18</emph>&nbsp;</td></tr><tr><td>zepto&nbsp;</td><td>z&nbsp;</td><td><code>z</code></td><td><code>ZO</code></td><td>1 &times; 10<emph role="sup">-21</emph>&nbsp;</td></tr><tr><td>yocto&nbsp;</td><td>y&nbsp;</td><td><code>y</code></td><td><code>YO</code></td><td>1 &times; 10<emph role="sup">-24</emph>&nbsp;</td></tr></table></div2><div2><head>Base Units</head><p name="base units"><emph role="strong"><anchor id="para-28">&sect;28</anchor> base units</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph> The base units shown in <tabref ref="baseunits"/> are used to
            define all the unit atoms of <emph>The Unified Code for Units of Measure</emph> according to its grammar and
            semantics.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph> There are five columns titled &ldquo;name,&rdquo; &ldquo;kind
            of quantity,&rdquo; &ldquo;print,&rdquo; &ldquo;c/s,&rdquo; and
            &ldquo;c/i.&rdquo; The name is the full (official) name of the
            unit. The official symbol used in print this is listed in the column
            &ldquo;print&rdquo; &ldquo;C/s,&rdquo; and &ldquo;c/i&rdquo; list the
            symbol in the case sensitive and the case insensitive variants
            respectively.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
            Only the columns titled &ldquo;c/s,&rdquo; and &ldquo;c/i,&rdquo; are
            normative. Full name and print symbol are defined by other bodies and
            are out of scope of <emph>The Unified Code for Units of Measure</emph>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;4</emph></emph> The selection of base units and the particular order are not
            normative. Any other basis <emph role="strong">B</emph>' that generates an
            isomorphic group of units is conformant with <emph>The Unified Code for Units of Measure</emph>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;5</emph></emph>
            If the other base <emph role="strong">B</emph>' generates a different system of units
            <emph>U</emph>' it conforms to <emph>The Unified Code for Units of Measure</emph> only if there is an homomorphism that maps
            <emph>U</emph>' onto <emph>U</emph>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;6</emph></emph>
            Base units must be metric units only. Special units can not be base
            units.
          </p><comment><p class="comment">
            As can be seen the base system used to define <emph>The Unified Code for Units of Measure</emph> is different
            from the system used by the <emph>Syst&egrave;me International
              d'Unit&eacute;s</emph> (SI) The SI base unit kilogram has been
            replaced by gram and the mole has been replaced by the radian that is
            defined dimensionless in the SI. Because of the latter change <emph>The Unified Code for Units of Measure</emph>
            is not isomorphic with the SI.
          </p><p class="comment">
            The replacement of the kilogram is trivial. In order to bring syntax
            and semantics in line we can not have a unit with prefix in the
            base. We need a valid unit of mass before we can combine it with the
            prefix &ldquo;kilo-&rdquo; This change does not have any effect on the
            semantics whatsoever.  The base unit kilogram is one of the oddities
            of the SI: if the gram would have been chosen as a base units the CGPM
            could have saved the rather annoying exception of the prefixing rules
            with the kilogram. At times where we have to multiply the wavelength
            of excited krypton-86 atoms by 1650763.73 to yield one meter, it seems
            trivial to divide the prototype of the kilogram by thousand to yield a
            base unit gram.
          </p><p class="comment">
            The rationale for removing the mole from the base is that the mole is
            essentially a count of particles expressed in a unit of very high
            magnitude (Avogadro's number). There is no fundamental difference
            between the count of particles and the count other things.
          </p><p class="comment">
            The radian has been adopted as the base unit of plane angle
            <emph>&alpha;</emph> to facilitate the distinction from the solid angle
            <emph>&Omega;</emph> by the relation <emph>&Omega;</emph> =
            <emph>&alpha;</emph><emph role="sup">2</emph> and to distinguish rotational frequency
            <emph>f</emph> from angular velocity <emph>&omega;</emph> = 2 <emph>&pi;</emph> &middot;
            rad &middot; <emph>f</emph>.
          </p></comment><table id="baseunits" max="7"><tr><th>name</th><th>kind of quantity</th><th>print</th><th>c/s</th><th>c/i</th></tr><caption> The base units upon which the semantics of all the unit
            atoms in <emph>The Unified Code for Units of Measure</emph> are defined. The selection of the base and the order
            of the units in the base are not normative. Any other base is
            acceptable as long as there is an isomorphism between the group of
            units generated by the other base system and this one. All base units
            are metric.</caption><tr><td>meter&nbsp;</td><td>length&nbsp;</td><td>m&nbsp;</td><td><code>m</code></td><td><code>M</code></td></tr><tr><td>second&nbsp;</td><td>time&nbsp;</td><td>s&nbsp;</td><td><code>s</code></td><td><code>S</code></td></tr><tr><td>gram&nbsp;</td><td>mass&nbsp;</td><td>g&nbsp;</td><td><code>g</code></td><td><code>G</code></td></tr><tr><td>radian&nbsp;</td><td>plane angle&nbsp;</td><td>rad&nbsp;</td><td><code>rad</code></td><td><code>RAD</code></td></tr><tr><td>kelvin&nbsp;</td><td>temperature&nbsp;</td><td>K&nbsp;</td><td><code>K</code></td><td><code>K</code></td></tr><tr><td>coulomb&nbsp;</td><td>electric charge&nbsp;</td><td>C&nbsp;</td><td><code>C</code></td><td><code>C</code></td></tr><tr><td>candela&nbsp;</td><td>luminous intensity&nbsp;</td><td>cd&nbsp;</td><td><code>cd</code></td><td><code>CD</code></td></tr></table></div2><div2><head>Derived Unit Atoms</head><p name="dimensionless units"><emph role="strong"><anchor id="para-29">&sect;29</anchor> dimensionless units</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            Dimensionless unit atoms are defined in <tabref ref="dimless"/>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph> There are seven columns titled &ldquo;name,&rdquo;
            &ldquo;print,&rdquo; &ldquo;c/s,&rdquo; &ldquo;c/i,&rdquo;
            &ldquo;M,&rdquo; &ldquo;value,&rdquo; and &ldquo;definition.&rdquo;
            The name is the full (official) name of the unit. The symbol
            recommended for use in print is listed in the column
            &ldquo;print.&rdquo; &ldquo;C/s,&rdquo; and &ldquo;c/i&rdquo; list the
            symbol in the case sensitive and the case insensitive variants
            respectively. 
            The column &ldquo;M&rdquo; specifies whether this is a
            metric unit. 
            The definition is a valid case sensitive expression of
            <emph>The Unified Code for Units of Measure</emph> that defines the unit atom.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
            Only the columns titled &ldquo;c/s,&rdquo; &ldquo;c/i,&rdquo;
            &ldquo;M,&rdquo; &ldquo;value,&rdquo; and &ldquo;definition&rdquo; are
            normative. Full name and print symbol are out of scope of <emph>The Unified Code for Units of Measure</emph>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;4</emph></emph>
            The units named &ldquo;parts per <emph>N</emph>&rdquo; are provided to be used
            where absolutely necessary but are not endorsed. Especially
            &ldquo;ppb&rdquo; and &ldquo;pptr&rdquo; are deprecated since
            &ldquo;billion&rdquo; and &ldquo;trillion&rdquo; are ambiguous names
            internationally. The explicit powers of ten should be given instead.
          </p><table id="dimless" omit="property"><tr><th>name</th><th>print</th><th>c/s</th><th>c/i</th><th>M</th><th>definition value</th><th>definition unit</th></tr><caption>Dimensionless units. The units ppb and ppt are deprecated
            because the names &ldquo;billion&rdquo; and &ldquo;trillion&rdquo; are
            ambiguous.  The expression &ldquo;<code>10*-9</code>&rdquo; or
            &ldquo;<code>10*-12</code>&rdquo; should be used instead. When the
            units percent or &ldquo;parts per <emph>N</emph>&rdquo; are used for
            concentrations specific units are preferred, e.g.,
            &ldquo;<code>ug/l</code>&rdquo; for mass concentration. The expression
            &ldquo;<code>ug/kg</code>&rdquo; for ppb is also valid.
          </caption><tr><td>the number ten for arbitrary powers&nbsp;</td><td>10<emph role="sup">n</emph>&nbsp;</td><td><code>10*</code>&nbsp;</td><td><code>10*</code>&nbsp;</td><td>no</td><td>10&nbsp;</td><td><code>1</code>&nbsp;</td></tr><tr><td>the number ten for arbitrary powers&nbsp;</td><td>10<emph role="sup">n</emph>&nbsp;</td><td><code>10^</code>&nbsp;</td><td><code>10^</code>&nbsp;</td><td>no</td><td>10&nbsp;</td><td><code>1</code>&nbsp;</td></tr><tr><td>the number pi&nbsp;</td><td>&pi;&nbsp;</td><td><code>[pi]</code>&nbsp;</td><td><code>[PI]</code>&nbsp;</td><td>no</td><td>&pi;&nbsp;</td><td><code>1</code>&nbsp;</td></tr><tr><td>percent&nbsp;</td><td>%&nbsp;</td><td><code>%</code>&nbsp;</td><td><code>%</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>10*-2</code>&nbsp;</td></tr><tr><td>parts per thousand&nbsp;</td><td>ppth&nbsp;</td><td><code>[ppth]</code>&nbsp;</td><td><code>[PPTH]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>10*-3</code>&nbsp;</td></tr><tr><td>parts per million&nbsp;</td><td>ppm&nbsp;</td><td><code>[ppm]</code>&nbsp;</td><td><code>[PPM]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>10*-6</code>&nbsp;</td></tr><tr><td>parts per billion&nbsp;</td><td>ppb&nbsp;</td><td><code>[ppb]</code>&nbsp;</td><td><code>[PPB]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>10*-9</code>&nbsp;</td></tr><tr><td>parts per trillion&nbsp;</td><td>pptr&nbsp;</td><td><code>[pptr]</code>&nbsp;</td><td><code>[PPTR]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>10*-12</code>&nbsp;</td></tr></table><comment><p class="comment">
            The notation &ldquo;<code>10*</code>&rdquo; for powers of ten
            originated in the HL7 &ldquo;ISO+&ldquo; extension of ISO&nbsp;2955.
            In HL7 the character carat (&lsquo;<code>^</code>&rsquo;) was thought as
            reserved. Since most people would expect to see
            &ldquo;<code>10^3</code>&rdquo; for the &ldquo;third power of
            ten&rdquo; and might in fact confuse &ldquo;<code>10*3</code>&rdquo;
            to mean &ldquo;ten times 3&rdquo;, the symbol using the carat was
            later added to <emph>The Unified Code for Units of Measure</emph>.
          </p></comment><p id="para-si" name="SI units"><emph role="strong"><anchor id="para-30">&sect;30</anchor> SI units</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            SI units are defined by the international <emph>Conf&eacute;rence
              G&eacute;n&eacute;rale des Poids et Mesures</emph> (CGPM).  <emph>The Unified Code for Units of Measure</emph> definitions
            for those units are given in <tabref ref="si"/>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph> There are seven columns titled &ldquo;name,&rdquo;
            &ldquo;print,&rdquo; &ldquo;c/s,&rdquo; &ldquo;c/i,&rdquo;
            &ldquo;M,&rdquo; &ldquo;value,&rdquo; and &ldquo;definition.&rdquo;
            The name is the full (official) name of the unit. The symbol
            recommended for use in print is listed in the column
            &ldquo;print.&rdquo; &ldquo;C/s,&rdquo; and &ldquo;c/i&rdquo; list the
            symbol in the case sensitive and the case insensitive variants
            respectively. 
            The column &ldquo;M&rdquo; specifies whether this is a
            metric unit. 
            The definition
            is a valid case sensitive expression of <emph>The Unified Code for Units of Measure</emph> that defines the unit
            atom.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
            Only the columns titled &ldquo;c/s,&rdquo; &ldquo;c/i,&rdquo;
            &ldquo;M,&rdquo; &ldquo;value,&rdquo; and &ldquo;definition&rdquo; are
            normative. Full name and print symbol are defined by the CGPM and are
            out of scope of <emph>The Unified Code for Units of Measure</emph>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;4</emph></emph>
            The function pair denoted &ldquo;<code>cel(1 K)</code>&rdquo; is
            defined as <emph>f</emph><emph role="sub">C</emph>(<emph>x</emph>) = <emph>x</emph> - 273.15 to
            convert from kelvin to degree Celsius, and
            <emph>f</emph><emph role="sub">C</emph><emph role="sup">-1</emph>(<emph>x</emph>) = <emph>x</emph> + 273.15 to
            convert from degree Celsius back to kelvin.
          </p><comment><p class="comment">
            The case insensitive symbol for pascal is
            &ldquo;<code>PAL</code>&rdquo; which conforms to ISO&nbsp;2955 and prevents
            the name conflict between pascal and pico-amp&egrave;re.
          </p><p class="comment">
            Without reference to history, it is difficult to explain that the
            degree Celsius is part of the SI, because the degree Celsius is in a
            unique way incoherent with the SI, and is even superfluous since the
            base unit kelvin measures the same kind of quantity.
          </p></comment><table id="si"><tr><th>name</th><th>kind of quantity</th><th>print</th><th>c/s</th><th>c/i</th><th>M</th><th>definition value</th><th>definition unit</th></tr><caption>SI units</caption><tr><td>mole&nbsp;</td><td>amount of substance&nbsp;</td><td>mol&nbsp;</td><td><code>mol</code>&nbsp;</td><td><code>MOL</code>&nbsp;</td><td>yes</td><td>6.02214076&nbsp;</td><td><code>10*23</code>&nbsp;</td></tr><tr><td>steradian&nbsp;</td><td>solid angle&nbsp;</td><td>sr&nbsp;</td><td><code>sr</code>&nbsp;</td><td><code>SR</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>rad2</code>&nbsp;</td></tr><tr><td>hertz&nbsp;</td><td>frequency&nbsp;</td><td>Hz&nbsp;</td><td><code>Hz</code>&nbsp;</td><td><code>HZ</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>s-1</code>&nbsp;</td></tr><tr><td>newton&nbsp;</td><td>force&nbsp;</td><td>N&nbsp;</td><td><code>N</code>&nbsp;</td><td><code>N</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>kg.m/s2</code>&nbsp;</td></tr><tr><td>pascal&nbsp;</td><td>pressure&nbsp;</td><td>Pa&nbsp;</td><td><code>Pa</code>&nbsp;</td><td><code>PAL</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>N/m2</code>&nbsp;</td></tr><tr><td>joule&nbsp;</td><td>energy&nbsp;</td><td>J&nbsp;</td><td><code>J</code>&nbsp;</td><td><code>J</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>N.m</code>&nbsp;</td></tr><tr><td>watt&nbsp;</td><td>power&nbsp;</td><td>W&nbsp;</td><td><code>W</code>&nbsp;</td><td><code>W</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>J/s</code>&nbsp;</td></tr><tr><td>amp&egrave;re&nbsp;</td><td>electric current&nbsp;</td><td>A&nbsp;</td><td><code>A</code>&nbsp;</td><td><code>A</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>C/s</code>&nbsp;</td></tr><tr><td>volt&nbsp;</td><td>electric potential&nbsp;</td><td>V&nbsp;</td><td><code>V</code>&nbsp;</td><td><code>V</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>J/C</code>&nbsp;</td></tr><tr><td>farad&nbsp;</td><td>electric capacitance&nbsp;</td><td>F&nbsp;</td><td><code>F</code>&nbsp;</td><td><code>F</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>C/V</code>&nbsp;</td></tr><tr><td>ohm&nbsp;</td><td>electric resistance&nbsp;</td><td>&Omega;&nbsp;</td><td><code>Ohm</code>&nbsp;</td><td><code>OHM</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>V/A</code>&nbsp;</td></tr><tr><td>siemens&nbsp;</td><td>electric conductance&nbsp;</td><td>S&nbsp;</td><td><code>S</code>&nbsp;</td><td><code>SIE</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>Ohm-1</code>&nbsp;</td></tr><tr><td>weber&nbsp;</td><td>magnetic flux&nbsp;</td><td>Wb&nbsp;</td><td><code>Wb</code>&nbsp;</td><td><code>WB</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>V.s</code>&nbsp;</td></tr><tr><td>degree Celsius&nbsp;</td><td>temperature&nbsp;</td><td>&deg;C&nbsp;</td><td><code>Cel</code>&nbsp;</td><td><code>CEL</code>&nbsp;</td><td>yes</td><td>&bull;&nbsp;</td><td><code>cel(1 K)</code>&nbsp;</td></tr><tr><td>tesla&nbsp;</td><td>magnetic flux density&nbsp;</td><td>T&nbsp;</td><td><code>T</code>&nbsp;</td><td><code>T</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>Wb/m2</code>&nbsp;</td></tr><tr><td>henry&nbsp;</td><td>inductance&nbsp;</td><td>H&nbsp;</td><td><code>H</code>&nbsp;</td><td><code>H</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>Wb/A</code>&nbsp;</td></tr><tr><td>lumen&nbsp;</td><td>luminous flux&nbsp;</td><td>lm&nbsp;</td><td><code>lm</code>&nbsp;</td><td><code>LM</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>cd.sr</code>&nbsp;</td></tr><tr><td>lux&nbsp;</td><td>illuminance&nbsp;</td><td>lx&nbsp;</td><td><code>lx</code>&nbsp;</td><td><code>LX</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>lm/m2</code>&nbsp;</td></tr><tr><td>becquerel&nbsp;</td><td>radioactivity&nbsp;</td><td>Bq&nbsp;</td><td><code>Bq</code>&nbsp;</td><td><code>BQ</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>s-1</code>&nbsp;</td></tr><tr><td>gray&nbsp;</td><td>energy dose&nbsp;</td><td>Gy&nbsp;</td><td><code>Gy</code>&nbsp;</td><td><code>GY</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>J/kg</code>&nbsp;</td></tr><tr><td>sievert&nbsp;</td><td>dose equivalent&nbsp;</td><td>Sv&nbsp;</td><td><code>Sv</code>&nbsp;</td><td><code>SV</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>J/kg</code>&nbsp;</td></tr></table><p id="para-other" name="other units from ISO&nbsp;1000, ISO&nbsp;2955 and ANSI&nbsp;X3.50"><emph role="strong"><anchor id="para-31">&sect;31</anchor> other units from ISO&nbsp;1000, ISO&nbsp;2955 and ANSI&nbsp;X3.50</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            Those unit atoms listed by ISO&nbsp;2955 under the heading &ldquo;other
            units from ISO&nbsp;1000&rdquo; and some units from ANSI&nbsp;X3.50 are defined
            in <tabref ref="iso1000"/>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            The meaning of the columns is declared in <termref ref="para-30">&sect;30</termref>.2.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
            Only the columns titled &ldquo;c/s,&rdquo; &ldquo;c/i,&rdquo;
            &ldquo;M,&rdquo; &ldquo;value,&rdquo; and &ldquo;definition&rdquo; are
            normative. Full name and print symbol are defined by ISO&nbsp;1000 and are
            out of scope of <emph>The Unified Code for Units of Measure</emph>.
          </p><table id="iso1000"><tr><th>name</th><th>kind of quantity</th><th>print</th><th>c/s</th><th>c/i</th><th>M</th><th>definition value</th><th>definition unit</th></tr><caption>Other units from ISO&nbsp;1000, ISO&nbsp;2955, and some from ANSI&nbsp;X3.50.</caption><tr><td>gon, grade&nbsp;</td><td>plane angle&nbsp;</td><td><emph role="sup">g</emph>&nbsp;</td><td><code>gon</code>&nbsp;</td><td><code>GON</code>&nbsp;</td><td>no</td><td>0.9&nbsp;</td><td><code>deg</code>&nbsp;</td></tr><tr><td>degree&nbsp;</td><td>plane angle&nbsp;</td><td>&deg;&nbsp;</td><td><code>deg</code>&nbsp;</td><td><code>DEG</code>&nbsp;</td><td>no</td><td>2&nbsp;</td><td><code>[pi].rad/360</code>&nbsp;</td></tr><tr><td>minute&nbsp;</td><td>plane angle&nbsp;</td><td>'&nbsp;</td><td><code>'</code>&nbsp;</td><td><code>'</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>deg/60</code>&nbsp;</td></tr><tr><td>second&nbsp;</td><td>plane angle&nbsp;</td><td>''&nbsp;</td><td><code>''</code>&nbsp;</td><td><code>''</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>'/60</code>&nbsp;</td></tr><tr><td>liter&nbsp;</td><td>volume&nbsp;</td><td>l&nbsp;</td><td><code>l</code>&nbsp;</td><td><code>L</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>dm3</code>&nbsp;</td></tr><tr><td>liter&nbsp;</td><td>volume&nbsp;</td><td>L&nbsp;</td><td><code>L</code>&nbsp;</td><td><code>L</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>l</code>&nbsp;</td></tr><tr><td>are&nbsp;</td><td>area&nbsp;</td><td>a&nbsp;</td><td><code>ar</code>&nbsp;</td><td><code>AR</code>&nbsp;</td><td>yes</td><td>100&nbsp;</td><td><code>m2</code>&nbsp;</td></tr><tr><td>minute&nbsp;</td><td>time&nbsp;</td><td>min&nbsp;</td><td><code>min</code>&nbsp;</td><td><code>MIN</code>&nbsp;</td><td>no</td><td>60&nbsp;</td><td><code>s</code>&nbsp;</td></tr><tr><td>hour&nbsp;</td><td>time&nbsp;</td><td>h&nbsp;</td><td><code>h</code>&nbsp;</td><td><code>HR</code>&nbsp;</td><td>no</td><td>60&nbsp;</td><td><code>min</code>&nbsp;</td></tr><tr><td>day&nbsp;</td><td>time&nbsp;</td><td>d&nbsp;</td><td><code>d</code>&nbsp;</td><td><code>D</code>&nbsp;</td><td>no</td><td>24&nbsp;</td><td><code>h</code>&nbsp;</td></tr><tr><td>tropical year&nbsp;</td><td>time&nbsp;</td><td>a<emph role="sub">t</emph>&nbsp;</td><td><code>a_t</code>&nbsp;</td><td><code>ANN_T</code>&nbsp;</td><td>no</td><td>365.24219&nbsp;</td><td><code>d</code>&nbsp;</td></tr><tr><td>mean Julian year&nbsp;</td><td>time&nbsp;</td><td>a<emph role="sub">j</emph>&nbsp;</td><td><code>a_j</code>&nbsp;</td><td><code>ANN_J</code>&nbsp;</td><td>no</td><td>365.25&nbsp;</td><td><code>d</code>&nbsp;</td></tr><tr><td>mean Gregorian year&nbsp;</td><td>time&nbsp;</td><td>a<emph role="sub">g</emph>&nbsp;</td><td><code>a_g</code>&nbsp;</td><td><code>ANN_G</code>&nbsp;</td><td>no</td><td>365.2425&nbsp;</td><td><code>d</code>&nbsp;</td></tr><tr><td>year&nbsp;</td><td>time&nbsp;</td><td>a&nbsp;</td><td><code>a</code>&nbsp;</td><td><code>ANN</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>a_j</code>&nbsp;</td></tr><tr><td>week&nbsp;</td><td>time&nbsp;</td><td>wk&nbsp;</td><td><code>wk</code>&nbsp;</td><td><code>WK</code>&nbsp;</td><td>no</td><td>7&nbsp;</td><td><code>d</code>&nbsp;</td></tr><tr><td>synodal month&nbsp;</td><td>time&nbsp;</td><td>mo<emph role="sub">s</emph>&nbsp;</td><td><code>mo_s</code>&nbsp;</td><td><code>MO_S</code>&nbsp;</td><td>no</td><td>29.53059&nbsp;</td><td><code>d</code>&nbsp;</td></tr><tr><td>mean Julian month&nbsp;</td><td>time&nbsp;</td><td>mo<emph role="sub">j</emph>&nbsp;</td><td><code>mo_j</code>&nbsp;</td><td><code>MO_J</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>a_j/12</code>&nbsp;</td></tr><tr><td>mean Gregorian month&nbsp;</td><td>time&nbsp;</td><td>mo<emph role="sub">g</emph>&nbsp;</td><td><code>mo_g</code>&nbsp;</td><td><code>MO_G</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>a_g/12</code>&nbsp;</td></tr><tr><td>month&nbsp;</td><td>time&nbsp;</td><td>mo&nbsp;</td><td><code>mo</code>&nbsp;</td><td><code>MO</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>mo_j</code>&nbsp;</td></tr><tr><td>tonne&nbsp;</td><td>mass&nbsp;</td><td>t&nbsp;</td><td><code>t</code>&nbsp;</td><td><code>TNE</code>&nbsp;</td><td>yes</td><td>1 &times; 10<emph role="sup">3</emph>&nbsp;</td><td><code>kg</code>&nbsp;</td></tr><tr><td>bar&nbsp;</td><td>pressure&nbsp;</td><td>bar&nbsp;</td><td><code>bar</code>&nbsp;</td><td><code>BAR</code>&nbsp;</td><td>yes</td><td>1 &times; 10<emph role="sup">5</emph>&nbsp;</td><td><code>Pa</code>&nbsp;</td></tr><tr><td>unified atomic mass unit&nbsp;</td><td>mass&nbsp;</td><td>u&nbsp;</td><td><code>u</code>&nbsp;</td><td><code>AMU</code>&nbsp;</td><td>yes</td><td>1.66053906660 &times; 10<emph role="sup">-24</emph>&nbsp;</td><td><code>g</code>&nbsp;</td></tr><tr><td>electronvolt&nbsp;</td><td>energy&nbsp;</td><td>eV&nbsp;</td><td><code>eV</code>&nbsp;</td><td><code>EV</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>[e].V</code>&nbsp;</td></tr><tr><td>astronomic unit&nbsp;</td><td>length&nbsp;</td><td>AU&nbsp;</td><td><code>AU</code>&nbsp;</td><td><code>ASU</code>&nbsp;</td><td>no</td><td>149597.870691&nbsp;</td><td><code>Mm</code>&nbsp;</td></tr><tr><td>parsec&nbsp;</td><td>length&nbsp;</td><td>pc&nbsp;</td><td><code>pc</code>&nbsp;</td><td><code>PRS</code>&nbsp;</td><td>yes</td><td>3.085678 &times; 10<emph role="sup">16</emph>&nbsp;</td><td><code>m</code>&nbsp;</td></tr></table><comment><p class="comment">
            In the case sensitive variant the liter is defined both with an upper
            case &lsquo;<code>L</code>&rdquo; and a lower case
            &lsquo;<code>l</code>&rsquo;. NIST [63 FR 40338] declares the upper case
            &lsquo;L&rsquo; as the preferred symbol for the U.S., while in many other
            countries the lower case &lsquo;l&rsquo; is used. In fact the lower case
            &lsquo;l&rsquo; was in effect since 1879. A hundred years later in 1979
            the 16th CGPM decided to adopt the upper case &lsquo;L&rsquo; as a
            second symbol for the liter.  In the case insensitive variant there is
            only one symbol defined since there is no difference between upper
            case &lsquo;L&rsquo; and lower case &lsquo;l&rsquo;.
          </p><p class="comment">
            The unit &ldquo;are&rdquo; competes with year for the symbol
            &ldquo;a&rdquo; not only in ISO&nbsp;2955, and ANSI&nbsp;X3.50, but also in
            ISO&nbsp;1000 as stating the official CGPM approved symbols. This is why
            the symbol for are is &ldquo;<code>ar</code>&rdquo; in
            <emph>The Unified Code for Units of Measure</emph>. ISO&nbsp;2955 explicitly adds the unit atom
            &ldquo;<code>ha</code>&rdquo; for hectare, while &ldquo;hectare&rdquo;
            is just the correct spelling of the compositum of &ldquo;hecto&rdquo;
            and &ldquo;are&rdquo; and thus would not require a separate unit
            atom. Nevertheless, ISO&nbsp;2955 in its case insensitive variant assigns
            &ldquo;<code>ARE</code>&rdquo; to the are and
            &ldquo;<code>har</code>&rdquo; to the hectare. This is obviously an
            anomaly which <emph>The Unified Code for Units of Measure</emph> will not follow. As a metric unit,
            &ldquo;<code>ar</code>&rdquo; can be prefixed with
            &ldquo;<code>h</code>&rdquo; to yield &ldquo;<code>har</code>&rdquo;
          </p><p class="comment">
            ANSI&nbsp;X3.50 had two different series of symbols for the units of time,
            the ones from ISO&nbsp;2955 as adopted by <emph>The Unified Code for Units of Measure</emph> and the symbols
            &ldquo;<code>yr</code>&rdquo; &ldquo;<code>mo</code>&rdquo;
            &ldquo;<code>wk</code>&rdquo; &ldquo;<code>hr</code>&rdquo; and
            &ldquo;<code>sec</code>&rdquo; while &ldquo;<code>d</code>&rdquo; and
            &ldquo;<code>min</code>&rdquo; were defined twice. <emph>The Unified Code for Units of Measure</emph> does not
            define these synonyms of ISO&nbsp;2955 symbols, but does adopt those units
            from ANSI&nbsp;X3.50 that are not part of ISO&nbsp;2955, namely
            &ldquo;<code>mo</code>&rdquo; and &ldquo;<code>wk</code>&rdquo; Month
            and week are useful units mainly in business or clinical medicine.
          </p><p class="comment">
            The semantics of the units of time is difficult to capture.  The
            difficulties start with the day: There is the sidereal and the solar
            day that depend on the earth's rotation. The earth's rotation is
            variable during one day and is continually slowing down in the long
            run.  The usual subdivisions of the day in 24 hours of 60 minutes and
            60 seconds originated in Babylonia. The earth's rotation was too
            inexact to measure time, which is why the 11th CGPM (1954) defined the
            second based on a standardized historical tropical year (see below)
            which was later (13th CGPM 1967-1968) replaced by frequency
            measurement. Thus the second came to be the base unit of time and the
            day is now 864000&nbsp;s exactly with the <emph>Universal Coordinated
              Time</emph> (UTC) adding leap seconds every now and then.
          </p><p class="comment">
            For the year we have to distinguish the &ldquo;tropical&rdquo; (solar,
            sidereal) year from the calendar year. And both are difficult. The
            tropical year is the year defined by time the earth travels around the
            sun. This is difficult to measure and varies over time.  Around 1900
            it was 365.242196&nbsp;d, currently it is 365.242190&nbsp;d and around
            2100 it will be 365.242184&nbsp;d.  In addition these durations are
            averages. The actual length of each year may vary by several minutes
            due to the gravitational influence of other planets. Thus there is
            quite a high uncertainty already in the fourth decimal digit.
          </p><p class="comment">
            The calendar year is also difficult because there is the Julian
            calendar (Sosigenes of Alexandria and Julius Caesar, 45 BC) with a
            slightly too long year of 365.25&nbsp;d that causes the calendar to be
            one day ahead of the tropical year in 128 years. The Gregorian
            calendar (Christopher Clavius 1537-1612 and Pope Gregory XIII
            1545-1563) leaves out three leap years in 400 years (let <emph>n</emph> be the
            year number, the leap year is dropped if <emph>n</emph> mod 100 = 0 but not <emph>n</emph>
            mod 400 = 0.) The Gregorian mean year is thus 365.2425&nbsp;d.
            This leap year arithmetic seems to be too much even for astronomers,
            which is why the light year ends up being defined based on the Julian
            year [NIST Sp.&nbsp;Pub. 811, 1995 Edition]. For this reason <emph>The Unified Code for Units of Measure</emph>
            defines Tropical, Julian and Gregorian year by means of subscripts,
            but assigns the default year symbol to the Julian year.
          </p><p class="comment">
            The week is 7 days, this is a biblic truth we can count on (it is
            actually quite plausible that the week of seven days originated in
            Babylonia and entered Jewish tradition during the Babylonian exile.)
          </p><p class="comment">
            The difficulty continues with the month. The lunar (so called
            &ldquo;synodal&rdquo; month is variable. Around 1900 it was
            29.5305886&nbsp;d currently it is 29.5305889&nbsp;d and in 2100 it
            will be 29.5305891&nbsp;d, which we fixate in the 5th decimal digit
            with a considerable uncertainty. The calendar month is difficult
            because of the uneven distribution of days in a month over the year,
            and because of the two different calendar years. But we will usually
            use the mean calendar month, which is the Julian calendar year divided
            by 12.
          </p><p class="comment">
            As a conclusion, great care has to be taken when the &ldquo;customary
            units&rdquo; of time are used to measure time. The SI has fixated the
            second which should be used whenever accuracy is required. For
            business purposes the Julian calendar is sufficient especially since
            the notion of the Work-Day (vs. Holiday) is more important than the
            imprecision over 128 years. 
            
            [Sources: &ldquo;Calendar&rdquo; <emph>Britannica Online.</emph><code>http://www.eb.com:180/cgi-bin/g?DocF=macro/5000/98/toc.html</code>.
            Claus Tondering, <emph>Frequently asked questions about
              calendars.</emph>
            Part&nbsp;1. 1998. <code>http://www.pip.dknet.dk/~c-t/calendar.faq1.txt</code>]
          </p></comment><p name="natural units"><emph role="strong"><anchor id="para-32">&sect;32</anchor> natural units</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            Fundamental constants of nature and units derived from these constants
            are defined in <tabref ref="const"/>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            The meaning of the columns is declared in  <termref ref="para-30">&sect;30</termref>.2.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
            Only the columns titled &ldquo;c/s,&rdquo; &ldquo;c/i,&rdquo;
            &ldquo;M,&rdquo; &ldquo;value,&rdquo; and &ldquo;definition&rdquo; are
            normative. Full name and print symbol are defined by ISO&nbsp;1000 and are
            out of scope of <emph>The Unified Code for Units of Measure</emph>.
          </p><table id="const"><tr><th>name</th><th>kind of quantity</th><th>print</th><th>c/s</th><th>c/i</th><th>M</th><th>definition value</th><th>definition unit</th></tr><caption>Natural units.</caption><tr><td>velocity of light&nbsp;</td><td>velocity&nbsp;</td><td><emph>c</emph>&nbsp;</td><td><code>[c]</code>&nbsp;</td><td><code>[C]</code>&nbsp;</td><td>yes</td><td>299792458&nbsp;</td><td><code>m/s</code>&nbsp;</td></tr><tr><td>Planck constant&nbsp;</td><td>action&nbsp;</td><td><emph>h</emph>&nbsp;</td><td><code>[h]</code>&nbsp;</td><td><code>[H]</code>&nbsp;</td><td>yes</td><td>6.62607015 &times; 10<emph role="sup">-34</emph>&nbsp;</td><td><code>J.s</code>&nbsp;</td></tr><tr><td>Boltzmann constant&nbsp;</td><td>(unclassified)&nbsp;</td><td><emph>k</emph>&nbsp;</td><td><code>[k]</code>&nbsp;</td><td><code>[K]</code>&nbsp;</td><td>yes</td><td>1.380649 &times; 10<emph role="sup">-23</emph>&nbsp;</td><td><code>J/K</code>&nbsp;</td></tr><tr><td>permittivity of vacuum&nbsp;</td><td>electric permittivity&nbsp;</td><td><emph>&epsilon;<emph role="sub"><r>0</r></emph></emph>&nbsp;</td><td><code>[eps_0]</code>&nbsp;</td><td><code>[EPS_0]</code>&nbsp;</td><td>yes</td><td>8.854187817 &times; 10<emph role="sup">-12</emph>&nbsp;</td><td><code>F/m</code>&nbsp;</td></tr><tr><td>permeability of vacuum&nbsp;</td><td>magnetic permeability&nbsp;</td><td><emph>&mu;<emph role="sub"><r>0</r></emph></emph>&nbsp;</td><td><code>[mu_0]</code>&nbsp;</td><td><code>[MU_0]</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>4.[pi].10*-7.N/A2</code>&nbsp;</td></tr><tr><td>elementary charge&nbsp;</td><td>electric charge&nbsp;</td><td><emph>e</emph>&nbsp;</td><td><code>[e]</code>&nbsp;</td><td><code>[E]</code>&nbsp;</td><td>yes</td><td>1.602176634 &times; 10<emph role="sup">-19</emph>&nbsp;</td><td><code>C</code>&nbsp;</td></tr><tr><td>electron mass&nbsp;</td><td>mass&nbsp;</td><td><emph>m<emph role="sub"><r>e</r></emph></emph>&nbsp;</td><td><code>[m_e]</code>&nbsp;</td><td><code>[M_E]</code>&nbsp;</td><td>yes</td><td>9.1093837139 &times; 10<emph role="sup">-31</emph>&nbsp;</td><td><code>kg</code>&nbsp;</td></tr><tr><td>proton mass&nbsp;</td><td>mass&nbsp;</td><td><emph>m<emph role="sub"><r>p</r></emph></emph>&nbsp;</td><td><code>[m_p]</code>&nbsp;</td><td><code>[M_P]</code>&nbsp;</td><td>yes</td><td>1.67262192595 &times; 10<emph role="sup">-27</emph>&nbsp;</td><td><code>kg</code>&nbsp;</td></tr><tr><td>Newtonian constant of gravitation&nbsp;</td><td>(unclassified)&nbsp;</td><td><emph>G</emph>&nbsp;</td><td><code>[G]</code>&nbsp;</td><td><code>[GC]</code>&nbsp;</td><td>yes</td><td>6.67430 &times; 10<emph role="sup">-11</emph>&nbsp;</td><td><code>m3.kg-1.s-2</code>&nbsp;</td></tr><tr><td>standard acceleration of free fall&nbsp;</td><td>acceleration&nbsp;</td><td><emph>g<emph role="sub">n</emph></emph>&nbsp;</td><td><code>[g]</code>&nbsp;</td><td><code>[G]</code>&nbsp;</td><td>yes</td><td>9.80665&nbsp;</td><td><code>m/s2</code>&nbsp;</td></tr><tr><td>standard atmosphere&nbsp;</td><td>pressure&nbsp;</td><td>atm&nbsp;</td><td><code>atm</code>&nbsp;</td><td><code>ATM</code>&nbsp;</td><td>no</td><td>101325&nbsp;</td><td><code>Pa</code>&nbsp;</td></tr><tr><td>light-year&nbsp;</td><td>length&nbsp;</td><td>l.y.&nbsp;</td><td><code>[ly]</code>&nbsp;</td><td><code>[LY]</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>[c].a_j</code>&nbsp;</td></tr><tr><td>gram-force&nbsp;</td><td>force&nbsp;</td><td>gf&nbsp;</td><td><code>gf</code>&nbsp;</td><td><code>GF</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>g.[g]</code>&nbsp;</td></tr><tr><td>pound force&nbsp;</td><td>force&nbsp;</td><td>lbf&nbsp;</td><td><code>[lbf_av]</code>&nbsp;</td><td><code>[LBF_AV]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[lb_av].[g]</code>&nbsp;</td></tr></table><comment><p class="comment">
            This list is not complete. It does not list all constants but only
            those that are fundamental and from which many other constants can be
            derived. The source of this table is <emph>The NIST Reference on
              Constants, Units, and Uncertainty</emph> Version 2.1, 21 May 1998. NIST
            Physics
            Laboratory. <code>http://physics.nist.gov/cuu/Constants/index.html</code></p><p class="comment">
            In the base system of <emph>The Unified Code for Units of Measure</emph>, the general gas constant <emph>R</emph> is
            identical to the Boltzmann constant <emph>k</emph>. In the SI both are related
            through <emph>R</emph> = <emph>k</emph> &times; <emph>N</emph><emph role="sub">A</emph>, where
            <emph>N</emph><emph role="sub">A</emph> = 6.02214076 &times; 10<emph role="sup">23</emph>&nbsp;/mol is
            the Avogadro constant. Because <emph>The Unified Code for Units of Measure</emph> defines the mole to be the
            dimensionless Avogadro number (number of particles in 1&nbsp;g of
            <emph role="sup">12</emph>C itself, there is no difference anymore if the Boltzmann
            constant is given as <emph>k</emph> = 1.380649 &times;
            10<emph role="sup">23</emph>&nbsp;J/K or <emph>R</emph> =
            8.314511&nbsp;J&nbsp;mol<emph role="sup">-1</emph>&nbsp;K<emph role="sup">-1</emph>.
          </p></comment><p name="CGS units"><emph role="strong"><anchor id="para-33">&sect;33</anchor> CGS units</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            The units of the older Centimeter-Gram-Second (CGS) system are defined
            in <tabref ref="cgs"/>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            The meaning of the columns is declared in  <termref ref="para-30">&sect;30</termref>.2.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
            Only the columns titled &ldquo;c/s,&rdquo; &ldquo;c/i,&rdquo;
            &ldquo;M,&rdquo; &ldquo;value,&rdquo; and &ldquo;definition&rdquo; are
            normative. Full name and print symbol are out of scope of <emph>The Unified Code for Units of Measure</emph>.
          </p><table id="cgs"><tr><th>name</th><th>kind of quantity</th><th>print</th><th>c/s</th><th>c/i</th><th>M</th><th>definition value</th><th>definition unit</th></tr><caption>CGS units</caption><tr><td>Kayser&nbsp;</td><td>lineic number&nbsp;</td><td>K&nbsp;</td><td><code>Ky</code>&nbsp;</td><td><code>KY</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>cm-1</code>&nbsp;</td></tr><tr><td>Gal&nbsp;</td><td>acceleration&nbsp;</td><td>Gal&nbsp;</td><td><code>Gal</code>&nbsp;</td><td><code>GL</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>cm/s2</code>&nbsp;</td></tr><tr><td>dyne&nbsp;</td><td>force&nbsp;</td><td>dyn&nbsp;</td><td><code>dyn</code>&nbsp;</td><td><code>DYN</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>g.cm/s2</code>&nbsp;</td></tr><tr><td>erg&nbsp;</td><td>energy&nbsp;</td><td>erg&nbsp;</td><td><code>erg</code>&nbsp;</td><td><code>ERG</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>dyn.cm</code>&nbsp;</td></tr><tr><td>Poise&nbsp;</td><td>dynamic viscosity&nbsp;</td><td>P&nbsp;</td><td><code>P</code>&nbsp;</td><td><code>P</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>dyn.s/cm2</code>&nbsp;</td></tr><tr><td>Biot&nbsp;</td><td>electric current&nbsp;</td><td>Bi&nbsp;</td><td><code>Bi</code>&nbsp;</td><td><code>BI</code>&nbsp;</td><td>yes</td><td>10&nbsp;</td><td><code>A</code>&nbsp;</td></tr><tr><td>Stokes&nbsp;</td><td>kinematic viscosity&nbsp;</td><td>St&nbsp;</td><td><code>St</code>&nbsp;</td><td><code>ST</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>cm2/s</code>&nbsp;</td></tr><tr><td>Maxwell&nbsp;</td><td>flux of magnetic induction&nbsp;</td><td>Mx&nbsp;</td><td><code>Mx</code>&nbsp;</td><td><code>MX</code>&nbsp;</td><td>yes</td><td>1 &times; 10<emph role="sup">-8</emph>&nbsp;</td><td><code>Wb</code>&nbsp;</td></tr><tr><td>Gauss&nbsp;</td><td>magnetic flux density&nbsp;</td><td>Gs, G&nbsp;</td><td><code>G</code>&nbsp;</td><td><code>GS</code>&nbsp;</td><td>yes</td><td>1 &times; 10<emph role="sup">-4</emph>&nbsp;</td><td><code>T</code>&nbsp;</td></tr><tr><td>Oersted&nbsp;</td><td>magnetic field intensity&nbsp;</td><td>Oe&nbsp;</td><td><code>Oe</code>&nbsp;</td><td><code>OE</code>&nbsp;</td><td>yes</td><td>250&nbsp;</td><td><code>/[pi].A/m</code>&nbsp;</td></tr><tr><td>Gilbert&nbsp;</td><td>magnetic tension&nbsp;</td><td>Gb&nbsp;</td><td><code>Gb</code>&nbsp;</td><td><code>GB</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>Oe.cm</code>&nbsp;</td></tr><tr><td>stilb&nbsp;</td><td>lum. intensity density&nbsp;</td><td>sb&nbsp;</td><td><code>sb</code>&nbsp;</td><td><code>SB</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>cd/cm2</code>&nbsp;</td></tr><tr><td>Lambert&nbsp;</td><td>brightness&nbsp;</td><td>L&nbsp;</td><td><code>Lmb</code>&nbsp;</td><td><code>LMB</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>cd/cm2/[pi]</code>&nbsp;</td></tr><tr><td>phot&nbsp;</td><td>illuminance&nbsp;</td><td>ph&nbsp;</td><td><code>ph</code>&nbsp;</td><td><code>PHT</code>&nbsp;</td><td>yes</td><td>1 &times; 10<emph role="sup">-4</emph>&nbsp;</td><td><code>lx</code>&nbsp;</td></tr><tr><td>Curie&nbsp;</td><td>radioactivity&nbsp;</td><td>Ci&nbsp;</td><td><code>Ci</code>&nbsp;</td><td><code>CI</code>&nbsp;</td><td>yes</td><td>3.7 &times; 10<emph role="sup">10</emph>&nbsp;</td><td><code>Bq</code>&nbsp;</td></tr><tr><td>Roentgen&nbsp;</td><td>ion dose&nbsp;</td><td>R&nbsp;</td><td><code>R</code>&nbsp;</td><td><code>ROE</code>&nbsp;</td><td>yes</td><td>2.58 &times; 10<emph role="sup">-4</emph>&nbsp;</td><td><code>C/kg</code>&nbsp;</td></tr><tr><td>radiation absorbed dose&nbsp;</td><td>energy dose&nbsp;</td><td>RAD&nbsp;</td><td><code>RAD</code>&nbsp;</td><td><code>[RAD]</code>&nbsp;</td><td>yes</td><td>100&nbsp;</td><td><code>erg/g</code>&nbsp;</td></tr><tr><td>radiation equivalent man&nbsp;</td><td>dose equivalent&nbsp;</td><td>REM&nbsp;</td><td><code>REM</code>&nbsp;</td><td><code>[REM]</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>RAD</code>&nbsp;</td></tr></table><comment><p class="comment">
            Although the CGPM &ldquo;accepts&rdquo; only very few CGS units &ldquo;for use with
            the SI,&rdquo; CGS units are proper metric units. CGS units are still used
            in many physiological laboratories and in clinical diagnostics (e.g.,
            cardiology). In addition CGS units acquired a special dignity as this
            was the system of units used by the great physicists of the early 20th
            century, Albert Einstein, Max Planck, and many others who worked on
            the scientific revolution that had quite a cultural impact.
          </p><p class="comment">
            The CGS system defined electric and magnetic phenomena differently
            which is why the units named &ldquo;oersted&rdquo; and &ldquo;maxwell&rdquo; have no
            proper SI counterpart. This table was compiled from various sources
            and is not complete and not very systematic. We therefore welcome
            suggestions and advice as to how this table could be completed.
          </p></comment></div2><div2><head>Customary Unit Atoms</head><comment><p class="comment">
            Customary units have once been used all over Europe. Units were taken
            from nature: anatomical structures (e.g., arm, foot, finger),
            botanical objects (e.g., grains of various sorts, rod), or processes
            of everyday life (e.g., amount of land one could plow in a morning,
            the length of 1000 steps, an hour of walking, etc.).
          </p><p class="comment">
            Many of these units can be traced back in history to the Romans
            (mile), Greeks (carat) and even more ancient times. It is thus no
            wonder that this heritage was in some way ordered. Indeed, one finds
            the same names for units used in different countries and most of these
            units where divided into smaller or multiplied to larger units in the
            same way.
          </p><p class="comment">
            For example, there was the foot (de. &ldquo;Fu&szlig;&rdquo;
            fr. &ldquo;pied&rdquo; nl. &ldquo;voet&rdquo;) that was divided into
            12 inches (de. &ldquo;Zoll&rdquo; fr. &ldquo;pouce&rdquo;). An inch
            was divided into 12 lines (de. &ldquo;Linie&rdquo;
            fr. &ldquo;ligne&rdquo; ). Two feet was one ell
            (de. &ldquo;Elle&rdquo; da. &ldquo;Alen&rdquo;
            sv. &ldquo;Aln&rdquo;). The ell was, however, not very popular in
            England, as opposed to the rest of Europe. Conversely, the yard is
            hard to find elsewhere, aside from the Argentinian &ldquo;vara.&rdquo;
            But it is perhaps no accident that the meter ended up as the 40 &times;
            10<emph role="sup">-6</emph> of an earth's meridian, which is approximately one
            yard (43.7 &times; 10<emph role="sup">-6</emph>). The rod (de. &ldquo;Rute&rdquo;
            fr. &ldquo;perche&rdquo; nl. &ldquo;roede&rdquo;
            sv. &ldquo;st&aring;ng&rdquo;) was very popular all over Europe and so
            was the fathom (de. &ldquo;Klafter&rdquo;).
          </p><p class="comment">
            The square rod (de. &ldquo;Quadratrute&rdquo;  fr. &ldquo;perche-carr&eacute;e&rdquo; 
            nl. &ldquo;vierkante-roede&rdquo;  was mainly used to measure land. The acre as
            the legendary land to sow in one morning (or day) is also widespread
            (de. &ldquo;Morgen, Tagwerk, Acker&rdquo;  fr. &ldquo;arpent&rdquo;  sv. &ldquo;tunnland&rdquo; ,
            although the exact amount in square rod varies considerably from
            region to region. Interestingly, even the special purpose measures
            such as the &ldquo;hand&rdquo; for measuring horses have international equivalents
            (de. &ldquo;faust&rdquo;).
          </p><p class="comment">
            One can indeed say that there was once a &ldquo;<emph>syst&egrave;me
              international d'unit&eacute;s coutumi&egrave;res</emph>&ldquo; but the
            magnitudes of the units were not standardized internationally. Of
            course, Great Britain had the most impact in standardizing the
            customary system, because of its colonies, including its most
            important colony, America. However, after the customary units were
            established in the U.S. a major reform took place through the British
            Weights and Measures Act of 1824. For instance, Queen Anne's wine
            Gallon of 231 cubic inches, still used in the U.S., was discarded
            then, and the older bushel was standardized differently in Great
            Britain.  Other deviations between the English and U.S. measures are
            due to various alignments with the metric system. Thus, in the U.S.,
            the yard was standardized as 3600/3937&nbsp;m and the inch was
            2.540005&nbsp;cm while in England the inch was still 2.539998&nbsp;cm.
          </p><p class="comment">
            In 1959 major parts of the U.S. and British system of customary units
            were standardized internationally, again aligned to the metric system
            which is why the international yard is 0.9144&nbsp;m exactly and the
            nautical mile became 1852&nbsp;m exactly. However, traditional
            subdivisions and multiples have not been abolished in favor of the
            international standard. Furthermore the old U.S. standard for the yard
            is still legally used for land surveying.
          </p><p class="comment">
            Conclusively, there are different systems of customary units that are
            in use today. These systems use the same names for units that have
            different equivalents in the metric system, because the customary
            systems are based on different reference quantities but multiples and
            subdivisions of the reference quantities are very similar, though with
            notable exceptions.
          </p><p class="comment">
            In the following tables we tried to give the original definitions to
            the customary units. This means in general that the references to the
            metric system are as few as possible, with most of the units of one
            system defined as multiples and subdivisions of one reference unit.
          </p><p class="comment">
            We use the subscript notation to disambiguate units with same names in
            the different systems. Subscript notation means, for instance that if
            the print symbol for foot is &ldquo;ft&rdquo; we use subscripts to
            distinguish the international foot &ldquo;ft<emph role="sub">i</emph>&rdquo; the
            U.S. survey foot &ldquo;ft<emph role="sub">us</emph>&rdquo; and the British
            Imperial foot &ldquo;ft<emph role="sub">br</emph>&rdquo; We do not actually list
            print symbols for customary units, because there seems to be no
            standard for it, and because defining print symbols is out of scope of
            <emph>The Unified Code for Units of Measure</emph>. However, we presume that subscripts be used to disambiguate
            whatever print symbols are being used. According to <termref ref="para-13">&sect;&sect;13ff</termref>, <emph>The Unified Code for Units of Measure</emph> uses the underscore to denote those
            subscripts, and also encloses the entire unit atom into square
            brackets. Hence, the symbols for the international foot, the
            U.S. survey foot and the British Imperial foot are defined as
            &ldquo;<code>[ft_i]</code>,&rdquo; &ldquo;<code>[ft_us]</code>,&rdquo;
            and &ldquo;<code>[ft_br]</code>&rdquo; respectively.
          </p><p class="comment">
            Prospective users of <emph>The Unified Code for Units of Measure</emph> may be disappointed by the fact that
            there are many different symbols for foot and inch defined but all of
            them have a subscript and thus none of them are equal to the
            ANSI&nbsp;X3.50 symbols. We considered to define default symbols for
            customary units, where, e.g., the common units of length (foot, inch)
            would default to the international customary units, while mass units
            (pound, ounce) would default to the avoirdupois system. However,
            because the customary system is quite complex, and units by the same
            names can differ by more than 20%, defining defaults will probably
            cause even more confusion. There is no denial: a gallon is not just a
            gallon and a pound is not just a pound, this is the disadvantage of
            dealing with a unit system of medieval origin.
          </p></comment><p id="para-custint" name="international customary units"><emph role="strong"><anchor id="para-34">&sect;34</anchor> international customary units</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            The unified U.S. and British Imperial customary units, so called
            &ldquo;international&rdquo; customary units are defined in <tabref ref="intcust"/>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            The meaning of the columns is declared in <termref ref="para-30">&sect;30</termref>.2.  With the exception that the column named
            &ldquo;print&rdquo; is not available.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
            Only the columns titled &ldquo;c/s,&rdquo; &ldquo;c/i,&rdquo;
            &ldquo;M,&rdquo; &ldquo;value,&rdquo; and &ldquo;definition&rdquo; are
            normative. The full name is out of scope of <emph>The Unified Code for Units of Measure</emph>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;4</emph></emph>
            The special symbols for &ldquo;square inch,&rdquo; &ldquo;cubic
            foot,&rdquo; etc. are deprecated. The preferred expressions use the
            exponents 2 and 3 respectively as shown in the column
            &ldquo;definition&rdquo;
          </p><table id="intcust" omit="printSymbol"><tr><th>name</th><th>kind of quantity</th><th>c/s</th><th>c/i</th><th>M</th><th>definition value</th><th>definition unit</th></tr><caption>International customary units</caption><tr><td>inch&nbsp;</td><td>length&nbsp;</td><td><code>[in_i]</code>&nbsp;</td><td><code>[IN_I]</code>&nbsp;</td><td>no</td><td>2.54&nbsp;</td><td><code>cm</code>&nbsp;</td></tr><tr><td>foot&nbsp;</td><td>length&nbsp;</td><td><code>[ft_i]</code>&nbsp;</td><td><code>[FT_I]</code>&nbsp;</td><td>no</td><td>12&nbsp;</td><td><code>[in_i]</code>&nbsp;</td></tr><tr><td>yard&nbsp;</td><td>length&nbsp;</td><td><code>[yd_i]</code>&nbsp;</td><td><code>[YD_I]</code>&nbsp;</td><td>no</td><td>3&nbsp;</td><td><code>[ft_i]</code>&nbsp;</td></tr><tr><td>mile&nbsp;</td><td>length&nbsp;</td><td><code>[mi_i]</code>&nbsp;</td><td><code>[MI_I]</code>&nbsp;</td><td>no</td><td>5280&nbsp;</td><td><code>[ft_i]</code>&nbsp;</td></tr><tr><td>fathom&nbsp;</td><td>depth of water&nbsp;</td><td><code>[fth_i]</code>&nbsp;</td><td><code>[FTH_I]</code>&nbsp;</td><td>no</td><td>6&nbsp;</td><td><code>[ft_i]</code>&nbsp;</td></tr><tr><td>nautical mile&nbsp;</td><td>length&nbsp;</td><td><code>[nmi_i]</code>&nbsp;</td><td><code>[NMI_I]</code>&nbsp;</td><td>no</td><td>1852&nbsp;</td><td><code>m</code>&nbsp;</td></tr><tr><td>knot&nbsp;</td><td>velocity&nbsp;</td><td><code>[kn_i]</code>&nbsp;</td><td><code>[KN_I]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[nmi_i]/h</code>&nbsp;</td></tr><tr><td>square inch&nbsp;</td><td>area&nbsp;</td><td><code>[sin_i]</code>&nbsp;</td><td><code>[SIN_I]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[in_i]2</code>&nbsp;</td></tr><tr><td>square foot&nbsp;</td><td>area&nbsp;</td><td><code>[sft_i]</code>&nbsp;</td><td><code>[SFT_I]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[ft_i]2</code>&nbsp;</td></tr><tr><td>square yard&nbsp;</td><td>area&nbsp;</td><td><code>[syd_i]</code>&nbsp;</td><td><code>[SYD_I]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[yd_i]2</code>&nbsp;</td></tr><tr><td>cubic inch&nbsp;</td><td>volume&nbsp;</td><td><code>[cin_i]</code>&nbsp;</td><td><code>[CIN_I]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[in_i]3</code>&nbsp;</td></tr><tr><td>cubic foot&nbsp;</td><td>volume&nbsp;</td><td><code>[cft_i]</code>&nbsp;</td><td><code>[CFT_I]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[ft_i]3</code>&nbsp;</td></tr><tr><td>cubic yard&nbsp;</td><td>volume&nbsp;</td><td><code>[cyd_i]</code>&nbsp;</td><td><code>[CYD_I]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[yd_i]3</code>&nbsp;</td></tr><tr><td>board foot&nbsp;</td><td>volume&nbsp;</td><td><code>[bf_i]</code>&nbsp;</td><td><code>[BF_I]</code>&nbsp;</td><td>no</td><td>144&nbsp;</td><td><code>[in_i]3</code>&nbsp;</td></tr><tr><td>cord&nbsp;</td><td>volume&nbsp;</td><td><code>[cr_i]</code>&nbsp;</td><td><code>[CR_I]</code>&nbsp;</td><td>no</td><td>128&nbsp;</td><td><code>[ft_i]3</code>&nbsp;</td></tr><tr><td>mil&nbsp;</td><td>length&nbsp;</td><td><code>[mil_i]</code>&nbsp;</td><td><code>[MIL_I]</code>&nbsp;</td><td>no</td><td>1 &times; 10<emph role="sup">-3</emph>&nbsp;</td><td><code>[in_i]</code>&nbsp;</td></tr><tr><td>circular mil&nbsp;</td><td>area&nbsp;</td><td><code>[cml_i]</code>&nbsp;</td><td><code>[CML_I]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[pi]/4.[mil_i]2</code>&nbsp;</td></tr><tr><td>hand&nbsp;</td><td>height of horses&nbsp;</td><td><code>[hd_i]</code>&nbsp;</td><td><code>[HD_I]</code>&nbsp;</td><td>no</td><td>4&nbsp;</td><td><code>[in_i]</code>&nbsp;</td></tr></table><comment><p class="comment">
            In general the international customary units are effective in the
            U.S. and in Great Britain since 1959. We are unsure, however, about
            this in countries that formerly or at present belong to the
            Commonwealth. We therefore appreciate advice and reference to original
            sources on this transition. Conceivably other countries may have made
            exceptions in the transition to the international definitions of
            customary units, such as the U.S. where the old definitions have been
            retained for the purpose of land surveying.
          </p><p class="comment">
            It is not quite clear exactly what units the international customary
            system comprises. According to the Encyclopedia Britannica
            [<emph>British Imperial System. Britannica Online</emph>], the rod was
            removed in Great Britain in 1963. Since the definition of the acre is
            based on the rod, we did not include rod and acre in the international
            customary system. In the U.S. the acre is still defined on the older
            U.S. customary system as of 1893.
          </p><p class="comment">
            In general, we did not include special customary units of area and
            volume in <tabref ref="intcust"/>, since these are still used
            differently in the U.S. Special symbols such as square inch and cubic
            foot have been included according to ANSI&nbsp;X3.50. Generally the
            &ldquo;square-&rdquo; and &ldquo;cubic-&rdquo; prefixes are
            unnecessary in ISO&nbsp;2955 and ANSI&nbsp;X3.50 and are deprecated by
            <emph>The Unified Code for Units of Measure</emph>. We placed the board foot, cord and circular mil into the
            international table because these units are suggested by
            ANSI&nbsp;X3.50 but we were not sure in what sense they are still
            used.  We did, however, not include the square mile in the
            international table because in the U.S. measurements in square miles
            are most likely based on the survey mile that is part of the older
            system, see <termref ref="para-35">&sect;35</termref>.
          </p><p class="comment">
            The circular mil is exactly the area of a circle with a diameter of
            one mil. One mil, in turn, equals 1/1000 inch (&ldquo;mil&rdquo; is the
            etymological equivalent of &ldquo;milli-inch&rdquo; ) The mil has been
            defined in <tabref ref="intcust"/> to support the exact definition of
            the circular mil.
          </p><p class="comment">
            ANSI X3.50 does not define a symbol for the &ldquo;hand,&rdquo; but this unit is
            mentioned in the table given by the Encyclopedia Britannica. The hand
            is used in measuring the height of horses from foot to shoulder. It
            was probably not subject to the internationalization of customary
            units. Any advice as whether the hand is used based on an older
            British or U.S. definition is appreciated.
          </p></comment><p id="para-us-lengths" name="U.S. survey lengths"><emph role="strong"><anchor id="para-35">&sect;35</anchor> U.S. survey lengths</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            The older U.S. units according to the definition of the inch in the
            U.S. Metric Law of 1866 and the definition of foot and yard that was
            valid from 1893 until 1959.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            The meaning of the columns is declared in <termref ref="para-34">&sect;34</termref>.
          <emph role="small">
            [Barry N. Taylor, <emph>Guide to the Use of the International System of
              Units (SI)</emph> [NIST Special Publication 811], National Institute for
            Standards and Technology (NIST), 1995. Available from: URL:
            <code>http://physics.nist.gov/Document/sp811.pdf</code>]
          </emph></p><table id="us-lengths" omit="printSymbol"><tr><th>name</th><th>kind of quantity</th><th>c/s</th><th>c/i</th><th>M</th><th>definition value</th><th>definition unit</th></tr><caption>Older U.S. &ldquo;survey&rdquo; lengths (also called "statute" lengths)</caption><tr><td>foot&nbsp;</td><td>length&nbsp;</td><td><code>[ft_us]</code>&nbsp;</td><td><code>[FT_US]</code>&nbsp;</td><td>no</td><td>1200&nbsp;</td><td><code>m/3937</code>&nbsp;</td></tr><tr><td>yard&nbsp;</td><td>length&nbsp;</td><td><code>[yd_us]</code>&nbsp;</td><td><code>[YD_US]</code>&nbsp;</td><td>no</td><td>3&nbsp;</td><td><code>[ft_us]</code>&nbsp;</td></tr><tr><td>inch&nbsp;</td><td>length&nbsp;</td><td><code>[in_us]</code>&nbsp;</td><td><code>[IN_US]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[ft_us]/12</code>&nbsp;</td></tr><tr><td>rod&nbsp;</td><td>length&nbsp;</td><td><code>[rd_us]</code>&nbsp;</td><td><code>[RD_US]</code>&nbsp;</td><td>no</td><td>16.5&nbsp;</td><td><code>[ft_us]</code>&nbsp;</td></tr><tr><td>Gunter's chain, Surveyor's chain&nbsp;</td><td>length&nbsp;</td><td><code>[ch_us]</code>&nbsp;</td><td><code>[CH_US]</code>&nbsp;</td><td>no</td><td>4&nbsp;</td><td><code>[rd_us]</code>&nbsp;</td></tr><tr><td>link for Gunter's chain&nbsp;</td><td>length&nbsp;</td><td><code>[lk_us]</code>&nbsp;</td><td><code>[LK_US]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[ch_us]/100</code>&nbsp;</td></tr><tr><td>Ramden's chain, Engineer's chain&nbsp;</td><td>length&nbsp;</td><td><code>[rch_us]</code>&nbsp;</td><td><code>[RCH_US]</code>&nbsp;</td><td>no</td><td>100&nbsp;</td><td><code>[ft_us]</code>&nbsp;</td></tr><tr><td>link for Ramden's chain&nbsp;</td><td>length&nbsp;</td><td><code>[rlk_us]</code>&nbsp;</td><td><code>[RLK_US]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[rch_us]/100</code>&nbsp;</td></tr><tr><td>fathom&nbsp;</td><td>length&nbsp;</td><td><code>[fth_us]</code>&nbsp;</td><td><code>[FTH_US]</code>&nbsp;</td><td>no</td><td>6&nbsp;</td><td><code>[ft_us]</code>&nbsp;</td></tr><tr><td>furlong&nbsp;</td><td>length&nbsp;</td><td><code>[fur_us]</code>&nbsp;</td><td><code>[FUR_US]</code>&nbsp;</td><td>no</td><td>40&nbsp;</td><td><code>[rd_us]</code>&nbsp;</td></tr><tr><td>mile&nbsp;</td><td>length&nbsp;</td><td><code>[mi_us]</code>&nbsp;</td><td><code>[MI_US]</code>&nbsp;</td><td>no</td><td>8&nbsp;</td><td><code>[fur_us]</code>&nbsp;</td></tr><tr><td>acre&nbsp;</td><td>area&nbsp;</td><td><code>[acr_us]</code>&nbsp;</td><td><code>[ACR_US]</code>&nbsp;</td><td>no</td><td>160&nbsp;</td><td><code>[rd_us]2</code>&nbsp;</td></tr><tr><td>square rod&nbsp;</td><td>area&nbsp;</td><td><code>[srd_us]</code>&nbsp;</td><td><code>[SRD_US]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[rd_us]2</code>&nbsp;</td></tr><tr><td>square mile&nbsp;</td><td>area&nbsp;</td><td><code>[smi_us]</code>&nbsp;</td><td><code>[SMI_US]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[mi_us]2</code>&nbsp;</td></tr><tr><td>section&nbsp;</td><td>area&nbsp;</td><td><code>[sct]</code>&nbsp;</td><td><code>[SCT]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[mi_us]2</code>&nbsp;</td></tr><tr><td>township&nbsp;</td><td>area&nbsp;</td><td><code>[twp]</code>&nbsp;</td><td><code>[TWP]</code>&nbsp;</td><td>no</td><td>36&nbsp;</td><td><code>[sct]</code>&nbsp;</td></tr><tr><td>mil&nbsp;</td><td>length&nbsp;</td><td><code>[mil_us]</code>&nbsp;</td><td><code>[MIL_US]</code>&nbsp;</td><td>no</td><td>1 &times; 10<emph role="sup">-3</emph>&nbsp;</td><td><code>[in_us]</code>&nbsp;</td></tr></table><comment><p class="comment">
            After the 1959 international agreement changed the definition of the yard in the US to be 0.9144 m exactly, surveyors and civil engineers complained that voluminous legacy surveys and so forth used the previous definition of (1200/3937) m and that this change would be disruptive. So, by statute, Congress created a survey foot of (1200/3937) m (the old 1893 Mendenhall Order definition). Thus, by statute, miles used in surveying are referred to as statute miles of 5280 survey feet each. The fathom, rod, and furlong are likewise based on the survey foot.
          </p><p class="comment">
            According to NIST, the acre as normally used in the U.S. is defined
            in terms of U.S. survey lengths, and not in terms of the
            international customary system.  This older U.S. customary system of
            survey lengths is still used for geodesic measurements.
          </p></comment><p name="British Imperial lengths"><emph role="strong"><anchor id="para-36">&sect;36</anchor> British Imperial lengths</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph><tabref ref="brit-length"/> defines symbols for the older British Imperial lengths as of
            the British Weights and Measures Act of 1824.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            The meaning of the columns is declared in  <termref ref="para-34">&sect;34</termref>.
          </p><table id="brit-length" omit="printSymbol"><tr><th>name</th><th>kind of quantity</th><th>c/s</th><th>c/i</th><th>M</th><th>definition value</th><th>definition unit</th></tr><caption>British Imperial lengths</caption><tr><td>inch&nbsp;</td><td>length&nbsp;</td><td><code>[in_br]</code>&nbsp;</td><td><code>[IN_BR]</code>&nbsp;</td><td>no</td><td>2.539998&nbsp;</td><td><code>cm</code>&nbsp;</td></tr><tr><td>foot&nbsp;</td><td>length&nbsp;</td><td><code>[ft_br]</code>&nbsp;</td><td><code>[FT_BR]</code>&nbsp;</td><td>no</td><td>12&nbsp;</td><td><code>[in_br]</code>&nbsp;</td></tr><tr><td>rod&nbsp;</td><td>length&nbsp;</td><td><code>[rd_br]</code>&nbsp;</td><td><code>[RD_BR]</code>&nbsp;</td><td>no</td><td>16.5&nbsp;</td><td><code>[ft_br]</code>&nbsp;</td></tr><tr><td>Gunter's chain&nbsp;</td><td>length&nbsp;</td><td><code>[ch_br]</code>&nbsp;</td><td><code>[CH_BR]</code>&nbsp;</td><td>no</td><td>4&nbsp;</td><td><code>[rd_br]</code>&nbsp;</td></tr><tr><td>link for Gunter's chain&nbsp;</td><td>length&nbsp;</td><td><code>[lk_br]</code>&nbsp;</td><td><code>[LK_BR]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[ch_br]/100</code>&nbsp;</td></tr><tr><td>fathom&nbsp;</td><td>length&nbsp;</td><td><code>[fth_br]</code>&nbsp;</td><td><code>[FTH_BR]</code>&nbsp;</td><td>no</td><td>6&nbsp;</td><td><code>[ft_br]</code>&nbsp;</td></tr><tr><td>pace&nbsp;</td><td>length&nbsp;</td><td><code>[pc_br]</code>&nbsp;</td><td><code>[PC_BR]</code>&nbsp;</td><td>no</td><td>2.5&nbsp;</td><td><code>[ft_br]</code>&nbsp;</td></tr><tr><td>yard&nbsp;</td><td>length&nbsp;</td><td><code>[yd_br]</code>&nbsp;</td><td><code>[YD_BR]</code>&nbsp;</td><td>no</td><td>3&nbsp;</td><td><code>[ft_br]</code>&nbsp;</td></tr><tr><td>mile&nbsp;</td><td>length&nbsp;</td><td><code>[mi_br]</code>&nbsp;</td><td><code>[MI_BR]</code>&nbsp;</td><td>no</td><td>5280&nbsp;</td><td><code>[ft_br]</code>&nbsp;</td></tr><tr><td>nautical mile&nbsp;</td><td>length&nbsp;</td><td><code>[nmi_br]</code>&nbsp;</td><td><code>[NMI_BR]</code>&nbsp;</td><td>no</td><td>6080&nbsp;</td><td><code>[ft_br]</code>&nbsp;</td></tr><tr><td>knot&nbsp;</td><td>velocity&nbsp;</td><td><code>[kn_br]</code>&nbsp;</td><td><code>[KN_BR]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[nmi_br]/h</code>&nbsp;</td></tr><tr><td>acre&nbsp;</td><td>area&nbsp;</td><td><code>[acr_br]</code>&nbsp;</td><td><code>[ACR_BR]</code>&nbsp;</td><td>no</td><td>4840&nbsp;</td><td><code>[yd_br]2</code>&nbsp;</td></tr></table><comment><p class="comment">
            The older British Imperial system is predominantly of historical
            interest. However, it may be that some former members of the
            Commonwealth have retained this system after 1959, when the unified
            international definitions where established, and after 1963, when the
            British system was revised in England.
          </p><p class="comment"> 
            The chain was proposed by Edmund Gunter in England of the 17th
            century. It is possible that Gunter's chain and Ramden's chain are
            related to other European traditional units such as the English
            &ldquo;rope&rdquo; (measuring 20 feet) or the old German
            &ldquo;Landseil&rdquo; (measuring 52 ells or 104 feet) named after
            ropes or chains that could be spanned in order to measure land. The
            difference in the definitions of those units is no surprise as there
            is nothing that restricts a chain or rope to a particular
            length. However, these units are still similar in magnitude.
          </p></comment><p id="para-us-volumes" name="U.S. volumes"><emph role="strong"><anchor id="para-37">&sect;37</anchor> U.S. volumes</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            The U.S. volumes, so called &ldquo;capacity&rdquo; measures, which
            are different for fluid goods (wine) and dry goods (grain), are
            defined in <tabref ref="us-volumes"/>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            The meaning of the columns is declared in <termref ref="para-34">&sect;34</termref>.
          </p><table id="us-volumes" omit="printSymbol"><tr><th>name</th><th>kind of quantity</th><th>c/s</th><th>c/i</th><th>M</th><th>definition value</th><th>definition unit</th></tr><caption>U.S. volumes including so called &ldquo;dry measures&rdquo;</caption><tr><td>Queen&nbsp;Anne's wine gallon&nbsp;</td><td>fluid volume&nbsp;</td><td><code>[gal_us]</code>&nbsp;</td><td><code>[GAL_US]</code>&nbsp;</td><td>no</td><td>231&nbsp;</td><td><code>[in_i]3</code>&nbsp;</td></tr><tr><td>barrel&nbsp;</td><td>fluid volume&nbsp;</td><td><code>[bbl_us]</code>&nbsp;</td><td><code>[BBL_US]</code>&nbsp;</td><td>no</td><td>42&nbsp;</td><td><code>[gal_us]</code>&nbsp;</td></tr><tr><td>quart&nbsp;</td><td>fluid volume&nbsp;</td><td><code>[qt_us]</code>&nbsp;</td><td><code>[QT_US]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[gal_us]/4</code>&nbsp;</td></tr><tr><td>pint&nbsp;</td><td>fluid volume&nbsp;</td><td><code>[pt_us]</code>&nbsp;</td><td><code>[PT_US]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[qt_us]/2</code>&nbsp;</td></tr><tr><td>gill&nbsp;</td><td>fluid volume&nbsp;</td><td><code>[gil_us]</code>&nbsp;</td><td><code>[GIL_US]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[pt_us]/4</code>&nbsp;</td></tr><tr><td>fluid ounce&nbsp;</td><td>fluid volume&nbsp;</td><td><code>[foz_us]</code>&nbsp;</td><td><code>[FOZ_US]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[gil_us]/4</code>&nbsp;</td></tr><tr><td>fluid dram&nbsp;</td><td>fluid volume&nbsp;</td><td><code>[fdr_us]</code>&nbsp;</td><td><code>[FDR_US]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[foz_us]/8</code>&nbsp;</td></tr><tr><td>minim&nbsp;</td><td>fluid volume&nbsp;</td><td><code>[min_us]</code>&nbsp;</td><td><code>[MIN_US]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[fdr_us]/60</code>&nbsp;</td></tr><tr><td>cord&nbsp;</td><td>fluid volume&nbsp;</td><td><code>[crd_us]</code>&nbsp;</td><td><code>[CRD_US]</code>&nbsp;</td><td>no</td><td>128&nbsp;</td><td><code>[ft_i]3</code>&nbsp;</td></tr><tr><td>bushel&nbsp;</td><td>dry volume&nbsp;</td><td><code>[bu_us]</code>&nbsp;</td><td><code>[BU_US]</code>&nbsp;</td><td>no</td><td>2150.42&nbsp;</td><td><code>[in_i]3</code>&nbsp;</td></tr><tr><td>historical winchester gallon&nbsp;</td><td>dry volume&nbsp;</td><td><code>[gal_wi]</code>&nbsp;</td><td><code>[GAL_WI]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[bu_us]/8</code>&nbsp;</td></tr><tr><td>peck&nbsp;</td><td>dry volume&nbsp;</td><td><code>[pk_us]</code>&nbsp;</td><td><code>[PK_US]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[bu_us]/4</code>&nbsp;</td></tr><tr><td>dry quart&nbsp;</td><td>dry volume&nbsp;</td><td><code>[dqt_us]</code>&nbsp;</td><td><code>[DQT_US]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[pk_us]/8</code>&nbsp;</td></tr><tr><td>dry pint&nbsp;</td><td>dry volume&nbsp;</td><td><code>[dpt_us]</code>&nbsp;</td><td><code>[DPT_US]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[dqt_us]/2</code>&nbsp;</td></tr><tr><td>tablespoon&nbsp;</td><td>volume&nbsp;</td><td><code>[tbs_us]</code>&nbsp;</td><td><code>[TBS_US]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[foz_us]/2</code>&nbsp;</td></tr><tr><td>teaspoon&nbsp;</td><td>volume&nbsp;</td><td><code>[tsp_us]</code>&nbsp;</td><td><code>[TSP_US]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[tbs_us]/3</code>&nbsp;</td></tr><tr><td>cup&nbsp;</td><td>volume&nbsp;</td><td><code>[cup_us]</code>&nbsp;</td><td><code>[CUP_US]</code>&nbsp;</td><td>no</td><td>16&nbsp;</td><td><code>[tbs_us]</code>&nbsp;</td></tr><tr><td>metric fluid ounce&nbsp;</td><td>fluid volume&nbsp;</td><td><code>[foz_m]</code>&nbsp;</td><td><code>[FOZ_M]</code>&nbsp;</td><td>no</td><td>30&nbsp;</td><td><code>mL</code>&nbsp;</td></tr><tr><td>metric cup&nbsp;</td><td>volume&nbsp;</td><td><code>[cup_m]</code>&nbsp;</td><td><code>[CUP_M]</code>&nbsp;</td><td>no</td><td>240&nbsp;</td><td><code>mL</code>&nbsp;</td></tr><tr><td>metric teaspoon&nbsp;</td><td>volume&nbsp;</td><td><code>[tsp_m]</code>&nbsp;</td><td><code>[TSP_M]</code>&nbsp;</td><td>no</td><td>5&nbsp;</td><td><code>mL</code>&nbsp;</td></tr><tr><td>metric tablespoon&nbsp;</td><td>volume&nbsp;</td><td><code>[tbs_m]</code>&nbsp;</td><td><code>[TBS_M]</code>&nbsp;</td><td>no</td><td>15&nbsp;</td><td><code>mL</code>&nbsp;</td></tr></table><comment><p class="comment">
            The U.S. fluid volumes have been defined based on Queen Anne's wine
            gallon which was in turn defined exactly as 231 cubic inch. Although
            we used international inch, we are not sure what inch definition is
            actually used for defining the exact size of a U.S. gallon. However,
            the differences between the various inches are minimal, even when
            raised to the 3rd power (i.e., the difference between the U.S. inch
            and the British Imperial inch remains in the sixth decimal digit.)
          </p><p class="comment">
            Dry measures are based on the bushel (corn bushel), originally defined
            in 1701 as &ldquo;any round measure with a plain and even bottom, being
            18.5 inches wide throughout and 8 inches deep.&rdquo; This definition,
            being (18.5/2)<emph role="sup">2</emph> &pi; &times; 8 = 2150.42017138221... cubic
            inch was later truncated to 2150.42 cubic inch exactly. At times the
            bushel was closely related with the Winchester gallon (corn gallon),
            which has been mentioned as an historical curiosity.
          </p><p class="comment">
            ANSI&nbsp;X3.50 defines symbols for the units cup, tablespoon and teaspoon
            which are predominantly used in cooking recipes but also in practical
            medicine. Similar units can often be found in European cook books, but
            are usually translated into metric units outside the U.S. For
            practical medicine these are still very handy units to give
            instructions to patients.
          </p></comment><p id="para-brit-volume" name="British Imperial volumes"><emph role="strong"><anchor id="para-38">&sect;38</anchor> British Imperial volumes</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            British Imperial volumes according to the Weights and Measures Act of
            1824 are defined in <tabref ref="brit-volumes"/>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            The meaning of the columns is declared in  <termref ref="para-34">&sect;34</termref>.
          </p><table id="brit-volumes" omit="printSymbol"><tr><th>name</th><th>kind of quantity</th><th>c/s</th><th>c/i</th><th>M</th><th>definition value</th><th>definition unit</th></tr><caption>British Imperial volumes</caption><tr><td>gallon&nbsp;</td><td>volume&nbsp;</td><td><code>[gal_br]</code>&nbsp;</td><td><code>[GAL_BR]</code>&nbsp;</td><td>no</td><td>4.54609&nbsp;</td><td><code>l</code>&nbsp;</td></tr><tr><td>peck&nbsp;</td><td>volume&nbsp;</td><td><code>[pk_br]</code>&nbsp;</td><td><code>[PK_BR]</code>&nbsp;</td><td>no</td><td>2&nbsp;</td><td><code>[gal_br]</code>&nbsp;</td></tr><tr><td>bushel&nbsp;</td><td>volume&nbsp;</td><td><code>[bu_br]</code>&nbsp;</td><td><code>[BU_BR]</code>&nbsp;</td><td>no</td><td>4&nbsp;</td><td><code>[pk_br]</code>&nbsp;</td></tr><tr><td>quart&nbsp;</td><td>volume&nbsp;</td><td><code>[qt_br]</code>&nbsp;</td><td><code>[QT_BR]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[gal_br]/4</code>&nbsp;</td></tr><tr><td>pint&nbsp;</td><td>volume&nbsp;</td><td><code>[pt_br]</code>&nbsp;</td><td><code>[PT_BR]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[qt_br]/2</code>&nbsp;</td></tr><tr><td>gill&nbsp;</td><td>volume&nbsp;</td><td><code>[gil_br]</code>&nbsp;</td><td><code>[GIL_BR]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[pt_br]/4</code>&nbsp;</td></tr><tr><td>fluid ounce&nbsp;</td><td>volume&nbsp;</td><td><code>[foz_br]</code>&nbsp;</td><td><code>[FOZ_BR]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[gil_br]/5</code>&nbsp;</td></tr><tr><td>fluid dram&nbsp;</td><td>volume&nbsp;</td><td><code>[fdr_br]</code>&nbsp;</td><td><code>[FDR_BR]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[foz_br]/8</code>&nbsp;</td></tr><tr><td>minim&nbsp;</td><td>volume&nbsp;</td><td><code>[min_br]</code>&nbsp;</td><td><code>[MIN_BR]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[fdr_br]/60</code>&nbsp;</td></tr></table><comment><p class="comment">
            The British Weights and Measures Act of 1824 removed the medieval
            distinction between wine and grain measures and defined one unified
            system of volumes based on a new Gallon that was defined similarly as
            the metric unit liter: &ldquo;10 imperial pounds weight of distilled
            water weighed in air against brass weights with the water and the air
            at a temperature of 62 degrees of Fahrenheit's thermometer and with
            the barometer at 30 inches.&rdquo;
          </p><p class="comment">
            With the current definition of the gallon as 277.421 cubic inches
            (approximately) and a density of water of 0.99878&nbsp;kg/l according
            to NIST data, the inch must have been approximately 2.5371&nbsp;cm at
            that time. Because of this difficulty with the original definition of
            the British gallon we based the British Imperial volumes on the gallon
            for which there is an exact metric equivalence, according to NIST,
            which provides usually well researched data.
          </p><p class="comment">
            Note that the subdivisions of the British Imperial system of volumes
            differs from the U.S. system of fluid volumes between gill and fluid
            ounce: in the British system 1&nbsp;oz&nbsp;fl equals 1/5&nbsp;gill where
            in the U.S. system 1&nbsp;oz&nbsp;fl equals 1/4&nbsp;gill. Thus, although
            the British system starts out with a 20% larger gallon, the British
            fluid ounce, fluid dram and minim are 4% smaller than the U.S. units
            with the same name.
          </p></comment><p name="avoirdupois weights"><emph role="strong"><anchor id="para-39">&sect;39</anchor> avoirdupois weights</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            The avoirdupois system of mass units is defined in <tabref ref="avoirdupois"/>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            The meaning of the columns is declared in  <termref ref="para-34">&sect;34</termref>.
          </p><comment><p class="comment">
            The avoirdupois system is used in the U.S. as well as in countries that
            use the British Imperial system. Avoirdupois is the default system of
            mass units used for all goods that &ldquo;have weight&rdquo;
            (fr. <emph>avoir du poids</emph>). Interestingly all three systems of
            weight are based on the same grain of barley, standardized to
            64.79891&nbsp;mg exactly [NIST].
          </p></comment><table id="avoirdupois" omit="printSymbol"><tr><th>name</th><th>kind of quantity</th><th>c/s</th><th>c/i</th><th>M</th><th>definition value</th><th>definition unit</th></tr><caption>Avoirdupois weights</caption><tr><td>grain&nbsp;</td><td>mass&nbsp;</td><td><code>[gr]</code>&nbsp;</td><td><code>[GR]</code>&nbsp;</td><td>no</td><td>64.79891&nbsp;</td><td><code>mg</code>&nbsp;</td></tr><tr><td>pound&nbsp;</td><td>mass&nbsp;</td><td><code>[lb_av]</code>&nbsp;</td><td><code>[LB_AV]</code>&nbsp;</td><td>no</td><td>7000&nbsp;</td><td><code>[gr]</code>&nbsp;</td></tr><tr><td>ounce&nbsp;</td><td>mass&nbsp;</td><td><code>[oz_av]</code>&nbsp;</td><td><code>[OZ_AV]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[lb_av]/16</code>&nbsp;</td></tr><tr><td>dram&nbsp;</td><td>mass&nbsp;</td><td><code>[dr_av]</code>&nbsp;</td><td><code>[DR_AV]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[oz_av]/16</code>&nbsp;</td></tr><tr><td>short hundredweight, U.S. hundredweight&nbsp;</td><td>mass&nbsp;</td><td><code>[scwt_av]</code>&nbsp;</td><td><code>[SCWT_AV]</code>&nbsp;</td><td>no</td><td>100&nbsp;</td><td><code>[lb_av]</code>&nbsp;</td></tr><tr><td>long hundredweight, British hundredweight&nbsp;</td><td>mass&nbsp;</td><td><code>[lcwt_av]</code>&nbsp;</td><td><code>[LCWT_AV]</code>&nbsp;</td><td>no</td><td>112&nbsp;</td><td><code>[lb_av]</code>&nbsp;</td></tr><tr><td>short ton, U.S. ton&nbsp;</td><td>mass&nbsp;</td><td><code>[ston_av]</code>&nbsp;</td><td><code>[STON_AV]</code>&nbsp;</td><td>no</td><td>20&nbsp;</td><td><code>[scwt_av]</code>&nbsp;</td></tr><tr><td>long ton, British ton&nbsp;</td><td>mass&nbsp;</td><td><code>[lton_av]</code>&nbsp;</td><td><code>[LTON_AV]</code>&nbsp;</td><td>no</td><td>20&nbsp;</td><td><code>[lcwt_av]</code>&nbsp;</td></tr><tr><td>stone, British stone&nbsp;</td><td>mass&nbsp;</td><td><code>[stone_av]</code>&nbsp;</td><td><code>[STONE_AV]</code>&nbsp;</td><td>no</td><td>14&nbsp;</td><td><code>[lb_av]</code>&nbsp;</td></tr></table><p name="troy weights"><emph role="strong"><anchor id="para-40">&sect;40</anchor> troy weights</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            The troy system of mass units is defined in <tabref ref="troy"/>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            The meaning of the columns is declared in  <termref ref="para-34">&sect;34</termref>.
          </p><comment><p class="comment">
            The troy system originates in Troyes, a City in the Champagne (France)
            that hosted a major European fair. The troy system was later used for
            measuring precious metals. The World Monetary Fund valued all
            currencies against the troy ounce of gold at least until the 1960s
            (advice appreciated). The troy ounce is still used in worldwide trade
            with gold, even in countries that otherwise use metric units
            (de. &ldquo;feinunze&rdquo;). The troy system retains the original Roman
            subdivision of the pound in 12 ounces. The Roman <emph>uncia</emph> was &ldquo;one
            twelfth&rdquo; of a <emph>libra</emph> (hence the symbol &ldquo;lb&rdquo; for the pound),
            just as the inch (also originating from la. &ldquo;libra&rdquo;  is one twelfth
            of a foot. The subdivision of 12 ounces/inches per pound/foot and 2
            foot per ell (la. &ldquo;cubit&rdquo;  apparently originated in the ancient
            Egypt and was carried on by the Greeks and Romans into the medieval
            Europe. However, there was always an ambiguity such that the
            subdivision of 1/12 could become 1/16 and vice versa, hence the
            avoirdupois ounce of 1/16 pound.
          </p><p class="comment">
            Note also that the troy pound was abolished in England on January 6,
            1879 [Jacques J. Proot, <emph>Anglo-Saxon weights &amp; measures</emph>, URL:
            <code>http://members.aol.com/JackProot/met/spvolas.html</code>].
          </p></comment><table id="troy" omit="printSymbol"><tr><th>name</th><th>kind of quantity</th><th>c/s</th><th>c/i</th><th>M</th><th>definition value</th><th>definition unit</th></tr><caption>Troy weights</caption><tr><td>pennyweight&nbsp;</td><td>mass&nbsp;</td><td><code>[pwt_tr]</code>&nbsp;</td><td><code>[PWT_TR]</code>&nbsp;</td><td>no</td><td>24&nbsp;</td><td><code>[gr]</code>&nbsp;</td></tr><tr><td>ounce&nbsp;</td><td>mass&nbsp;</td><td><code>[oz_tr]</code>&nbsp;</td><td><code>[OZ_TR]</code>&nbsp;</td><td>no</td><td>20&nbsp;</td><td><code>[pwt_tr]</code>&nbsp;</td></tr><tr><td>pound&nbsp;</td><td>mass&nbsp;</td><td><code>[lb_tr]</code>&nbsp;</td><td><code>[LB_TR]</code>&nbsp;</td><td>no</td><td>12&nbsp;</td><td><code>[oz_tr]</code>&nbsp;</td></tr></table><p name="apothecaries' weights."><emph role="strong"><anchor id="para-41">&sect;41</anchor> apothecaries' weights.</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            The apothecaries' system of mass units is defined in <tabref ref="apoth"/>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            The meaning of the columns is declared in  <termref ref="para-34">&sect;34</termref>.
          </p><table id="apoth" omit="printSymbol"><tr><th>name</th><th>kind of quantity</th><th>c/s</th><th>c/i</th><th>M</th><th>definition value</th><th>definition unit</th></tr><caption>Apothecaries' weights</caption><tr><td>scruple&nbsp;</td><td>mass&nbsp;</td><td><code>[sc_ap]</code>&nbsp;</td><td><code>[SC_AP]</code>&nbsp;</td><td>no</td><td>20&nbsp;</td><td><code>[gr]</code>&nbsp;</td></tr><tr><td>dram, drachm&nbsp;</td><td>mass&nbsp;</td><td><code>[dr_ap]</code>&nbsp;</td><td><code>[DR_AP]</code>&nbsp;</td><td>no</td><td>3&nbsp;</td><td><code>[sc_ap]</code>&nbsp;</td></tr><tr><td>ounce&nbsp;</td><td>mass&nbsp;</td><td><code>[oz_ap]</code>&nbsp;</td><td><code>[OZ_AP]</code>&nbsp;</td><td>no</td><td>8&nbsp;</td><td><code>[dr_ap]</code>&nbsp;</td></tr><tr><td>pound&nbsp;</td><td>mass&nbsp;</td><td><code>[lb_ap]</code>&nbsp;</td><td><code>[LB_AP]</code>&nbsp;</td><td>no</td><td>12&nbsp;</td><td><code>[oz_ap]</code>&nbsp;</td></tr><tr><td>metric ounce&nbsp;</td><td>mass&nbsp;</td><td><code>[oz_m]</code>&nbsp;</td><td><code>[OZ_M]</code>&nbsp;</td><td>no</td><td>28&nbsp;</td><td><code>g</code>&nbsp;</td></tr></table><comment><p class="comment">
            Note that some U.S. pharmacies still use this system of apothecaries'
            weights when measuring the amount of drugs. This system is very
            different from the avoirdupois system though based on the same
            grain. The apothecaries' dram is more than twice as much as the
            avoirdupois dram, the ounce is still 10% greater than the avoirdupois
            ounce while the pound is 20% less than the avoirdupois pound. The
            apothecaries' system, just as the troy system, keeps the original
            Roman subdivision of an ounce (la. &ldquo;uncia&rdquo;  to be 1/12 pound
            (la. &ldquo;libra&rdquo;). Hence is the apothecaries' pound about 22% smaller
            than the avoirdupois pound, while its subdivisions are greater than
            the respective avoirdupois subdivisions (ounce 10%, dram 119%). This
            difference in the weight systems is the most important reason why
            ANSI&nbsp;X3.50 should not be applied in medicine, where both systems are
            being used and therefore misinterpretations are inevitable.
          </p></comment><p name="typesetter's lengths"><emph role="strong"><anchor id="para-42">&sect;42</anchor> typesetter's lengths</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            The units of length as used in typesetting are defined in <tabref ref="typeset"/>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            The meaning of the columns is declared in <termref ref="para-34">&sect;34</termref>.
          </p><table id="typeset" omit="printSymbol"><tr><th>name</th><th>kind of quantity</th><th>c/s</th><th>c/i</th><th>M</th><th>definition value</th><th>definition unit</th></tr><caption>Units used in typesetting</caption><tr><td>line&nbsp;</td><td>length&nbsp;</td><td><code>[lne]</code>&nbsp;</td><td><code>[LNE]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[in_i]/12</code>&nbsp;</td></tr><tr><td>point&nbsp;</td><td>length&nbsp;</td><td><code>[pnt]</code>&nbsp;</td><td><code>[PNT]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[lne]/6</code>&nbsp;</td></tr><tr><td>pica&nbsp;</td><td>length&nbsp;</td><td><code>[pca]</code>&nbsp;</td><td><code>[PCA]</code>&nbsp;</td><td>no</td><td>12&nbsp;</td><td><code>[pnt]</code>&nbsp;</td></tr><tr><td>Printer's point&nbsp;</td><td>length&nbsp;</td><td><code>[pnt_pr]</code>&nbsp;</td><td><code>[PNT_PR]</code>&nbsp;</td><td>no</td><td>0.013837&nbsp;</td><td><code>[in_i]</code>&nbsp;</td></tr><tr><td>Printer's pica&nbsp;</td><td>length&nbsp;</td><td><code>[pca_pr]</code>&nbsp;</td><td><code>[PCA_PR]</code>&nbsp;</td><td>no</td><td>12&nbsp;</td><td><code>[pnt_pr]</code>&nbsp;</td></tr><tr><td>pied, French foot&nbsp;</td><td>length&nbsp;</td><td><code>[pied]</code>&nbsp;</td><td><code>[PIED]</code>&nbsp;</td><td>no</td><td>32.48&nbsp;</td><td><code>cm</code>&nbsp;</td></tr><tr><td>pouce, French inch&nbsp;</td><td>length&nbsp;</td><td><code>[pouce]</code>&nbsp;</td><td><code>[POUCE]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[pied]/12</code>&nbsp;</td></tr><tr><td>ligne, French line&nbsp;</td><td>length&nbsp;</td><td><code>[ligne]</code>&nbsp;</td><td><code>[LIGNE]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[pouce]/12</code>&nbsp;</td></tr><tr><td>didot, Didot's point&nbsp;</td><td>length&nbsp;</td><td><code>[didot]</code>&nbsp;</td><td><code>[DIDOT]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[ligne]/6</code>&nbsp;</td></tr><tr><td>cicero, Didot's pica&nbsp;</td><td>length&nbsp;</td><td><code>[cicero]</code>&nbsp;</td><td><code>[CICERO]</code>&nbsp;</td><td>no</td><td>12&nbsp;</td><td><code>[didot]</code>&nbsp;</td></tr></table><comment><p class="comment">
            There are three systems of typesetter's lengths in use today:
            Fran&ccedil;cois-Ambroise Didot (1730-1804), a publisher in Paris,
            invented this system based on the traditional subdivisions of the
            customary units: 1 line was 1/12 inch and 1/6 line was one
            point. Henceforth the size of letters were measured in point. However,
            the Didot system is based on the <emph>pouce</emph>, i.e. the french
            inch, which, just as the English inch, is 1/12 <emph>pied</emph>
            (foot). But the French foot was about 6.5% greater than the British
            Imperial foot. In the Anglo-American realm the typesetter's point was
            based on the British Imperial inch, with the same
            subdivisions. However, in the type foundries' industry the original
            definition of a point drifted apart, and in the late 19th century
            U.S. type foundries reestablished a slightly (0.375%) greater standard
            point. This point made its way back to the British. However, recently,
            the computer typesetting industry readjusted the point to its original
            size of 1/72 inch. All three systems, however, are still being used
            today.
          </p></comment></div2><div2><head>Other Legacy Units</head><p id="para-heat" name="legacy units for heat and temperature"><emph role="strong"><anchor id="para-43">&sect;43</anchor> legacy units for heat and temperature</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            Older units of heat (energy) and temperature are defined in <tabref ref="heat"/>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            The meaning of the columns is declared in  <termref ref="para-30">&sect;30</termref>.2.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
            Only the columns titled &ldquo;c/s,&rdquo; &ldquo;c/i,&rdquo;
            &ldquo;M,&rdquo; &ldquo;value,&rdquo; and &ldquo;definition&rdquo; are
            normative. Full name and print symbol are either not standardized or
            standardized by other bodies and are out of scope of <emph>The Unified Code for Units of Measure</emph>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;4</emph></emph>
            The function pair denoted &ldquo;<code>degf(5 K/9)</code>&rdquo; is
            defined as <emph>f</emph><emph role="sub">F</emph>(<emph>x</emph>) = 9/5 <emph>x</emph> - 459.67 to convert
            from kelvin to degree Fahrenheit, and
            <emph>f</emph><emph role="sub">F</emph><emph role="sup">-1</emph>(<emph>x</emph>) = 5/9 (<emph>x</emph> + 459.67) to
            convert from degree Fahrenheit back to kelvin.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;5</emph></emph>
            The function pair denoted &ldquo;<code>degre(5 K/4)</code>&rdquo; is
            defined as <emph>f</emph><emph role="sub">R&eacute;</emph>(<emph>x</emph>) = 4/5 <emph>x</emph> - 218.52 to convert
            from kelvin to degree R&eacute;aumur, and
            <emph>f</emph><emph role="sub">R&eacute;</emph><emph role="sup">-1</emph>(<emph>x</emph>) = 5/4 (<emph>x</emph> + 218.52) to
            convert from degree R&eacute;aumur back to kelvin.
          </p><table id="heat"><tr><th>name</th><th>kind of quantity</th><th>print</th><th>c/s</th><th>c/i</th><th>M</th><th>definition value</th><th>definition unit</th></tr><caption>Other Units for Heat and Temperature</caption><tr><td>degree Fahrenheit&nbsp;</td><td>temperature&nbsp;</td><td>&deg;F&nbsp;</td><td><code>[degF]</code>&nbsp;</td><td><code>[DEGF]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td><code>degf(5 K/9)</code>&nbsp;</td></tr><tr><td>degree Rankine&nbsp;</td><td>temperature&nbsp;</td><td>&deg;R&nbsp;</td><td><code>[degR]</code>&nbsp;</td><td><code>[degR]</code>&nbsp;</td><td>no</td><td>5&nbsp;</td><td><code>K/9</code>&nbsp;</td></tr><tr><td>degree R&eacute;aumur&nbsp;</td><td>temperature&nbsp;</td><td>&deg;R&eacute;&nbsp;</td><td><code>[degRe]</code>&nbsp;</td><td><code>[degRe]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td><code>degre(5 K/4)</code>&nbsp;</td></tr><tr><td>calorie at 15&nbsp;&deg;C&nbsp;</td><td>energy&nbsp;</td><td>cal<emph role="sub">15&deg;C</emph>&nbsp;</td><td><code>cal_[15]</code>&nbsp;</td><td><code>CAL_[15]</code>&nbsp;</td><td>yes</td><td>4.18580&nbsp;</td><td><code>J</code>&nbsp;</td></tr><tr><td>calorie at 20&nbsp;&deg;C&nbsp;</td><td>energy&nbsp;</td><td>cal<emph role="sub">20&deg;C</emph>&nbsp;</td><td><code>cal_[20]</code>&nbsp;</td><td><code>CAL_[20]</code>&nbsp;</td><td>yes</td><td>4.18190&nbsp;</td><td><code>J</code>&nbsp;</td></tr><tr><td>mean calorie&nbsp;</td><td>energy&nbsp;</td><td>cal<emph role="sub">m</emph>&nbsp;</td><td><code>cal_m</code>&nbsp;</td><td><code>CAL_M</code>&nbsp;</td><td>yes</td><td>4.19002&nbsp;</td><td><code>J</code>&nbsp;</td></tr><tr><td>international table calorie&nbsp;</td><td>energy&nbsp;</td><td>cal<emph role="sub">IT</emph>&nbsp;</td><td><code>cal_IT</code>&nbsp;</td><td><code>CAL_IT</code>&nbsp;</td><td>yes</td><td>4.1868&nbsp;</td><td><code>J</code>&nbsp;</td></tr><tr><td>thermochemical calorie&nbsp;</td><td>energy&nbsp;</td><td>cal<emph role="sub">th</emph>&nbsp;</td><td><code>cal_th</code>&nbsp;</td><td><code>CAL_TH</code>&nbsp;</td><td>yes</td><td>4.184&nbsp;</td><td><code>J</code>&nbsp;</td></tr><tr><td>calorie&nbsp;</td><td>energy&nbsp;</td><td>cal&nbsp;</td><td><code>cal</code>&nbsp;</td><td><code>CAL</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>cal_th</code>&nbsp;</td></tr><tr><td>nutrition label Calories&nbsp;</td><td>energy&nbsp;</td><td>Cal&nbsp;</td><td><code>[Cal]</code>&nbsp;</td><td><code>[CAL]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>kcal_th</code>&nbsp;</td></tr><tr><td>British thermal unit at 39&nbsp;&deg;F&nbsp;</td><td>energy&nbsp;</td><td>Btu<emph role="sub">39&deg;F</emph>&nbsp;</td><td><code>[Btu_39]</code>&nbsp;</td><td><code>[BTU_39]</code>&nbsp;</td><td>no</td><td>1.05967&nbsp;</td><td><code>kJ</code>&nbsp;</td></tr><tr><td>British thermal unit at 59&nbsp;&deg;F&nbsp;</td><td>energy&nbsp;</td><td>Btu<emph role="sub">59&deg;F</emph>&nbsp;</td><td><code>[Btu_59]</code>&nbsp;</td><td><code>[BTU_59]</code>&nbsp;</td><td>no</td><td>1.05480&nbsp;</td><td><code>kJ</code>&nbsp;</td></tr><tr><td>British thermal unit at 60&nbsp;&deg;F&nbsp;</td><td>energy&nbsp;</td><td>Btu<emph role="sub">60&deg;F</emph>&nbsp;</td><td><code>[Btu_60]</code>&nbsp;</td><td><code>[BTU_60]</code>&nbsp;</td><td>no</td><td>1.05468&nbsp;</td><td><code>kJ</code>&nbsp;</td></tr><tr><td>mean British thermal unit&nbsp;</td><td>energy&nbsp;</td><td>Btu<emph role="sub">m</emph>&nbsp;</td><td><code>[Btu_m]</code>&nbsp;</td><td><code>[BTU_M]</code>&nbsp;</td><td>no</td><td>1.05587&nbsp;</td><td><code>kJ</code>&nbsp;</td></tr><tr><td>international table British thermal unit&nbsp;</td><td>energy&nbsp;</td><td>Btu<emph role="sub">IT</emph>&nbsp;</td><td><code>[Btu_IT]</code>&nbsp;</td><td><code>[BTU_IT]</code>&nbsp;</td><td>no</td><td>1.05505585262&nbsp;</td><td><code>kJ</code>&nbsp;</td></tr><tr><td>thermochemical British thermal unit&nbsp;</td><td>energy&nbsp;</td><td>Btu<emph role="sub">th</emph>&nbsp;</td><td><code>[Btu_th]</code>&nbsp;</td><td><code>[BTU_TH]</code>&nbsp;</td><td>no</td><td>1.054350&nbsp;</td><td><code>kJ</code>&nbsp;</td></tr><tr><td>British thermal unit&nbsp;</td><td>energy&nbsp;</td><td>btu&nbsp;</td><td><code>[Btu]</code>&nbsp;</td><td><code>[BTU]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[Btu_th]</code>&nbsp;</td></tr><tr><td>horsepower&nbsp;</td><td>power&nbsp;</td><td>&nbsp;</td><td><code>[HP]</code>&nbsp;</td><td><code>[HP]</code>&nbsp;</td><td>no</td><td>550&nbsp;</td><td><code>[ft_i].[lbf_av]/s</code>&nbsp;</td></tr><tr><td>tex&nbsp;</td><td>linear mass density (of textile thread)&nbsp;</td><td>tex&nbsp;</td><td><code>tex</code>&nbsp;</td><td><code>TEX</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>g/km</code>&nbsp;</td></tr><tr><td>Denier&nbsp;</td><td>linear mass density (of textile thread)&nbsp;</td><td>den&nbsp;</td><td><code>[den]</code>&nbsp;</td><td><code>[DEN]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>g/9/km</code>&nbsp;</td></tr></table><comment><p class="comment">
            The degree Fahrenheit was missing in ANSI&nbsp;X3.50. HL7's
            &ldquo;ISO+/ANS+&rdquo; code defined the degree Fahrenheit under the
            symbol &ldquo;<code>DEGF</code>&rdquo; which is reflected here. This
            is the reason why <emph>The Unified Code for Units of Measure</emph> does not define a new symbol
            &ldquo;<code>Fah</code>&rdquo; similar to
            &ldquo;<code>Cel</code>&rdquo; of 
            ISO&nbsp;2955 for the degree Celsius.
          </p><p class="comment">
            Defining precise semantics for legacy units for &ldquo;quantity of
            heat&rdquo; is difficult. The many variants of these units are
            frequently confused because there is not just a calorie and not just a
            British thermal unit. The different calories usually being used vary
            by 1% but the confusion can result in an error as high as 100000%!
            Thus, if exactness and non-ambiguity is important one should use the
            joule to report amounts of heat, just like for any other energy and
            work kind-of-quantities.
          </p><p class="comment">
            The gram-calorie, sometimes called &ldquo;small calorie&rdquo; is
            defined as the amount of heat required to raise the temperature of 1
            gram of Water from 14.5&nbsp;&deg;C to 15.5&nbsp;&deg;C. According to
            <emph>Encyclopedia Britannica</emph>, this is the calorie most often used in
            engineering. There is also a less frequently used gram-calorie at
            19.5&nbsp;&deg;C to 20.5&nbsp;&deg;C and a mean calorie that is 1/100
            of the amount of heat required to raise the temperature from
            0&nbsp;&deg;C to 100&nbsp;&deg;C. The <emph>International Table</emph>
            calorie is defined by the <emph>International Conference on the
              Properties of Steam</emph> (1956) and is used in steam engineering. In
            chemistry a &ldquo;thermochemical&rdquo; calorie is used for reaction
            enthalpies.
          </p><p class="comment">
            To complete the confusion, there is also a kilogram-calorie (&ldquo;large
            calorie&rdquo; , that has a similar definition based on a kilogram
            instead of a gram of water. This kilocalorie has also been called
            &ldquo;calorie&rdquo; in the sloppy speech of everyday life about
            food. U.S. &ldquo;Nutrition Facts&rdquo; that label almost every
            American food say &ldquo;Calories: xxx&rdquo; The <emph>International
              Union of Nutritional Sciences</emph> recommends using either the joule
            or a kilocalorie based on the thermochemical calorie. Because of a
            perceived popular demand <emph>The Unified Code for Units of Measure</emph> defines the nutrition Calorie as
            &ldquo;<code>Cal</code>&rdquo; with the conventional capital first
            letter. For the case insensitive variant of <emph>The Unified Code for Units of Measure</emph>, the symbol is
            enclosed in square brackets (&ldquo;<code>[CAL]</code>&rdquo;).
          </p><p class="comment">
            Only the International Table calorie and the thermochemical calorie
            have exact definitions. To give some guidance in the confusing plenty
            of different calories, <emph>The Unified Code for Units of Measure</emph> defines a default symbol
            &ldquo;<code>cal</code>&rdquo; as an alias for the thermochemical
            calorie, because the calorie is mostly used today in medicine and
            biochemistry. On the other hand, we consider engineers smart enough to
            select the precise calorie they mean.
          </p><p class="comment">
            Similar to the calories, various &ldquo;British Thermal Unit&rdquo;
            (Btu) are defined and the confusion continues. One Btu is defined as
            the amount of heat necessary to raise the temperature of one
            avoirdupois pound of water by one degree Fahrenheit beginning from
            various temperatures (39&nbsp;&deg;F, 59&nbsp;&deg;F, or
            60&nbsp;&deg;F). There is also the International Table Btu and the
            thermochemical Btu. Just as with the calorie we define a default
            symbol &ldquo;<code>Btu</code>&rdquo; as an alias for the
            thermochemical Btu.
          </p></comment><p name="units used predominantly in clinical medicine"><emph role="strong"><anchor id="para-44">&sect;44</anchor> units used predominantly in clinical medicine</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            Units used mainly in clinical medicine are defined in <tabref ref="clinical"/>. 
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            The meaning of the columns is declared in  <termref ref="para-34">&sect;34</termref>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
            The function pair denoted &ldquo;<code>hpX(1 l)</code>&rdquo; is
            defined as <emph>f</emph><emph role="sub">hp X</emph>(<emph>x</emph>) = - lg <emph>x</emph> to
            convert from a number fraction (dilution) per liter to the
            homeopathic potency value of the decimal (X) series, and <emph>f</emph><emph role="sub">hp
              X</emph><emph role="sup">-1</emph>(<emph>x</emph>) = 10<emph role="sup">-<emph>x</emph></emph> to convert
            from the potency value back to the number fraction. Likewise, the
            function pair denoted &ldquo;<code>hpC(1 l)</code>&rdquo; is defined
            as <emph>f</emph><emph role="sub">hp C</emph>(<emph>x</emph>) = - ln(<emph>x</emph>) / ln(100)
            to convert from a number fraction (dilution) per liter to the
            homeopathic potency value of the centesimal (C) series, and <emph>f</emph><emph role="sub">hp
              C</emph><emph role="sup">-1</emph>(<emph>x</emph>) = 100<emph role="sup">-<emph>x</emph></emph> to convert
            from the potency value back to the number fraction. Analogous 
            functions are defined for the millesimal (M) series with basis 1,000 
            and the series and the quintamillesimal (Q) series with basis 50,000.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;4</emph></emph>
            The function pair denoted &ldquo;<code>100tan(1 rad)</code>&rdquo; is
            defined as <emph>f</emph><emph role="sub">PD</emph>(<emph>&alpha;</emph>) = tan(<emph>&alpha;</emph>) &times; 100 to
            convert from a plane angle <emph>&alpha;</emph> to a prism diopter value (or a
            slope percent value) and
            <emph>f</emph><emph role="sub">PD</emph><emph role="sup">-1</emph>(<emph>x</emph>) = arctan(<emph>x / 100</emph>) to
            convert from prism diopter (or slope percent) value <emph>x</emph> back to a plane angle.
          </p><table id="clinical"><tr><th>name</th><th>kind of quantity</th><th>print</th><th>c/s</th><th>c/i</th><th>M</th><th>definition value</th><th>definition unit</th></tr><caption>Units Used Predominantly in Clinical Medicine</caption><tr><td>meter of water column&nbsp;</td><td>pressure&nbsp;</td><td>m&nbsp;H<emph role="sub"><r>2</r></emph>O&nbsp;</td><td><code>m[H2O]</code>&nbsp;</td><td><code>M[H2O]</code>&nbsp;</td><td>yes</td><td>9.80665&nbsp;</td><td><code>kPa</code>&nbsp;</td></tr><tr><td>meter of mercury column&nbsp;</td><td>pressure&nbsp;</td><td>m&nbsp;Hg&nbsp;</td><td><code>m[Hg]</code>&nbsp;</td><td><code>M[HG]</code>&nbsp;</td><td>yes</td><td>133.3220&nbsp;</td><td><code>kPa</code>&nbsp;</td></tr><tr><td>inch of water column&nbsp;</td><td>pressure&nbsp;</td><td>in&nbsp;H<emph role="sub"><r>2</r></emph>O&nbsp;</td><td><code>[in_i'H2O]</code>&nbsp;</td><td><code>[IN_I'H2O]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>m[H2O].[in_i]/m</code>&nbsp;</td></tr><tr><td>inch of mercury column&nbsp;</td><td>pressure&nbsp;</td><td>in&nbsp;Hg&nbsp;</td><td><code>[in_i'Hg]</code>&nbsp;</td><td><code>[IN_I'HG]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>m[Hg].[in_i]/m</code>&nbsp;</td></tr><tr><td>peripheral vascular resistance unit&nbsp;</td><td>fluid resistance&nbsp;</td><td>P.R.U.&nbsp;</td><td><code>[PRU]</code>&nbsp;</td><td><code>[PRU]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>mm[Hg].s/ml</code>&nbsp;</td></tr><tr><td>Wood unit&nbsp;</td><td>fluid resistance&nbsp;</td><td>Wood U.&nbsp;</td><td><code>[wood'U]</code>&nbsp;</td><td><code>[WOOD'U]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>mm[Hg].min/L</code>&nbsp;</td></tr><tr><td>diopter&nbsp;</td><td>refraction of a lens&nbsp;</td><td>dpt&nbsp;</td><td><code>[diop]</code>&nbsp;</td><td><code>[DIOP]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>/m</code>&nbsp;</td></tr><tr><td>prism diopter&nbsp;</td><td>refraction of a prism&nbsp;</td><td>PD&nbsp;</td><td><code>[p'diop]</code>&nbsp;</td><td><code>[P'DIOP]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td><code>100tan(1 rad)</code>&nbsp;</td></tr><tr><td>percent of slope&nbsp;</td><td>slope&nbsp;</td><td>%&nbsp;</td><td><code>%[slope]</code>&nbsp;</td><td><code>%[SLOPE]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td><code>100tan(1 rad)</code>&nbsp;</td></tr><tr><td>mesh&nbsp;</td><td>lineic number&nbsp;</td><td>&nbsp;</td><td><code>[mesh_i]</code>&nbsp;</td><td><code>[MESH_I]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>/[in_i]</code>&nbsp;</td></tr><tr><td>Charri&egrave;re, french&nbsp;</td><td>gauge of catheters&nbsp;</td><td>Ch&nbsp;</td><td><code>[Ch]</code>&nbsp;</td><td><code>[CH]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>mm/3</code>&nbsp;</td></tr><tr><td>drop&nbsp;</td><td>volume&nbsp;</td><td>drp&nbsp;</td><td><code>[drp]</code>&nbsp;</td><td><code>[DRP]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>ml/20</code>&nbsp;</td></tr><tr><td>Hounsfield unit&nbsp;</td><td>x-ray attenuation&nbsp;</td><td>HF&nbsp;</td><td><code>[hnsf'U]</code>&nbsp;</td><td><code>[HNSF'U]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>1</code>&nbsp;</td></tr><tr><td>metabolic equivalent&nbsp;</td><td>metabolic cost of physical activity&nbsp;</td><td>MET&nbsp;</td><td><code>[MET]</code>&nbsp;</td><td><code>[MET]</code>&nbsp;</td><td>no</td><td>3.5&nbsp;</td><td><code>mL/min/kg</code>&nbsp;</td></tr><tr><td>homeopathic potency of decimal series (retired)&nbsp;</td><td>homeopathic potency (retired)&nbsp;</td><td>X&nbsp;</td><td><code>[hp'_X]</code>&nbsp;</td><td><code>[HP'_X]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td><code>hpX(1 1)</code>&nbsp;</td></tr><tr><td>homeopathic potency of centesimal series (retired)&nbsp;</td><td>homeopathic potency (retired)&nbsp;</td><td>C&nbsp;</td><td><code>[hp'_C]</code>&nbsp;</td><td><code>[HP'_C]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td><code>hpC(1 1)</code>&nbsp;</td></tr><tr><td>homeopathic potency of millesimal series (retired)&nbsp;</td><td>homeopathic potency (retired)&nbsp;</td><td>M&nbsp;</td><td><code>[hp'_M]</code>&nbsp;</td><td><code>[HP'_M]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td><code>hpM(1 1)</code>&nbsp;</td></tr><tr><td>homeopathic potency of quintamillesimal series (retired)&nbsp;</td><td>homeopathic potency (retired)&nbsp;</td><td>Q&nbsp;</td><td><code>[hp'_Q]</code>&nbsp;</td><td><code>[HP'_Q]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td><code>hpQ(1 1)</code>&nbsp;</td></tr><tr><td>homeopathic potency of decimal hahnemannian series&nbsp;</td><td>homeopathic potency (Hahnemann)&nbsp;</td><td>X&nbsp;</td><td><code>[hp_X]</code>&nbsp;</td><td><code>[HP_X]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>homeopathic potency of centesimal hahnemannian series&nbsp;</td><td>homeopathic potency (Hahnemann)&nbsp;</td><td>C&nbsp;</td><td><code>[hp_C]</code>&nbsp;</td><td><code>[HP_C]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>homeopathic potency of millesimal hahnemannian series&nbsp;</td><td>homeopathic potency (Hahnemann)&nbsp;</td><td>M&nbsp;</td><td><code>[hp_M]</code>&nbsp;</td><td><code>[HP_M]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>homeopathic potency of quintamillesimal hahnemannian series&nbsp;</td><td>homeopathic potency (Hahnemann)&nbsp;</td><td>Q&nbsp;</td><td><code>[hp_Q]</code>&nbsp;</td><td><code>[HP_Q]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>homeopathic potency of decimal korsakovian series&nbsp;</td><td>homeopathic potency (Korsakov)&nbsp;</td><td>X&nbsp;</td><td><code>[kp_X]</code>&nbsp;</td><td><code>[KP_X]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>homeopathic potency of centesimal korsakovian series&nbsp;</td><td>homeopathic potency (Korsakov)&nbsp;</td><td>C&nbsp;</td><td><code>[kp_C]</code>&nbsp;</td><td><code>[KP_C]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>homeopathic potency of millesimal korsakovian series&nbsp;</td><td>homeopathic potency (Korsakov)&nbsp;</td><td>M&nbsp;</td><td><code>[kp_M]</code>&nbsp;</td><td><code>[KP_M]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>homeopathic potency of quintamillesimal korsakovian series&nbsp;</td><td>homeopathic potency (Korsakov)&nbsp;</td><td>Q&nbsp;</td><td><code>[kp_Q]</code>&nbsp;</td><td><code>[KP_Q]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr></table><comment><p class="comment">
            Clinical medicine all over the world still uses &nbsp;mm&nbsp;Hg to
            measure arterial blood pressure, and often the instruments used are
            real mercury columns. Likewise, the central venous blood pressure is
            often measured using simple water columns which is very practical for
            the routine. The units &nbsp;m&nbsp;H<emph role="sub">2</emph>O and &nbsp;m&nbsp;Hg
            are metric units even though they are &ldquo;not accepted&rdquo; for
            use with the SI for quite a while. Although more and more hospitals in
            Europe switch to using the pascal to measure partial pressures in
            blood gas analysis, the older units will not vanish any time soon.
          </p><p class="comment">
            In the U.S. the inch is sometimes used instead of the millimeter, and
            because the inch is non-metric the inch of mercury or water columns is
            non-metric as well.
          </p><p class="comment">
            The peripheral vascular resistance unit is the vascular resistance on
            which a perfusion pressure of 1&nbsp;mm&nbsp;Hg causes a flow of
            1&nbsp;ml/s.
          </p><p class="comment">
            The &ldquo;mesh&rdquo; occurs in the NIST Guide to the SI. It seems like it is
            the customary counterpart of the diopter.
          </p><p class="comment">
            The unit &ldquo;charri&egrave;re&rdquo; originates from a French manufacturer of
            medical instruments by that name. One charri&egrave;re is the gauge of a
            catheter with a circumference of approximately 1&nbsp;mm 
            such that it is by convention exactly one third of a millimeter. 
            In the U.S. the charri&egrave;re is simply called &ldquo;french&rdquo; 
          </p><note><p class="comment">
              Note that <emph>Unified Code for Units of Measure</emph> versions prior to 1.9 defined this unit as 1/&pi;, this use, 
              however this was never common use of the unit. 
              This is why the definition has been corrected instead of adding another one.
            </p></note><p class="comment">
            A drop is a variable amount of fluid and depends on the device and
            technique used to produce the drop and on the physical properties of
            the fluid. This is similar to units like cup, tablespoon, and teaspoon
            that depend on the spoon or cup and are not exact either. However, in
            clinical medicine medication is dispensed by drops and unlike a
            &ldquo;tablet&rdquo; a drop refers to a real physical kind of quantity, volume,
            though not very exact.
          </p><note><p class="comment">
              Note that <emph>Unified Code for Units of Measure</emph> versions prior to 1.9 defined this unit as mL/12, this use, 
              however this was not common use of the unit.  
              This is why the definition has been corrected instead of adding another one.
              Typically it is stated as mL/20.
              Original research using a 20 mL syringe filled to 5 mL shows that 
              1 mL has 25 drops of water, 
              when tensides are added, the number goes up to 45. 
              A saturated saline solution required 30 and plant oil 35. 
              The speed of dropping, pressure and position of the syringe or the lumen of the outlet, 
              open or partially clogged with wax, 
              did not have a significant influence on the number of drops.
              While the original research suggests that the division should be by 25 or more, we use the common notion.
              It is discouraged to use the drop as any standard unit.
            </p></note><p class="comment">
            The Hounsfield unit is a unit of X-ray attenuation used in evaluating
            CT scans. It is defined on an interval scale where air is -1000 HF,
            water is 0 HF and bone is +1000 HF. Any advice as to how this unit can
            be related to metric units of radiant intensity decremence is
            appreciated.
          </p><p class="comment">
            We have always pointed out that the homeopathic teaching takes potency
            not as equivalent to dilution and the C and X series would not equate
            to each other in the strictly numerical manner. Homeopathic potency
            includes the &ldquo;agitation&rdquo; (a vigorous shaking) that needs
            to occur in every step of the dilluting process. Therefore as of April 2010, 
            the homeopathic units are declared "arbitrary units", that is, they 
            are no longer convertible. Therefore, also, we discontinue defining them
            using the dilution functions. The dilution functions sometimes cause
            truly astronomical values, leading to overflow conditions, e.g. in 
            such potencies as 30 C or 100 X or 10 M, which do actually occur in
            homeopathics that are on the market. The previous units continue to
            exist as "retired", but their symbols now have a prime (apostrophe) in
            them.
          </p></comment><p name="chemical and biochemical units"><emph role="strong"><anchor id="para-45">&sect;45</anchor> chemical and biochemical units</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            Units used mainly in chemical and biochemical laboratories are defined
            in <tabref ref="chemical"/>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            The meaning of the columns is declared in  <termref ref="para-43">&sect;43</termref>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
            The function pair denoted &ldquo;<code>ph(1 mol/l)</code>&rdquo; is
            defined as <emph>f</emph><emph role="sub">pH</emph>(<emph>x</emph>) = - lg <emph>x</emph> to
            convert from moles per liter to the pH value, and
            <emph>f</emph><emph role="sub">pH</emph><emph role="sup">-1</emph>(<emph>x</emph>) = 10<emph role="sup">-<emph>x</emph></emph>
            to convert from the pH value back to moles per liter.
          </p><table id="chemical"><tr><th>name</th><th>kind of quantity</th><th>print</th><th>c/s</th><th>c/i</th><th>M</th><th>definition value</th><th>definition unit</th></tr><caption>Units used in Chemical and Biomedical Laboratories</caption><tr><td>equivalents&nbsp;</td><td>amount of substance&nbsp;</td><td>eq&nbsp;</td><td><code>eq</code>&nbsp;</td><td><code>EQ</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>mol</code>&nbsp;</td></tr><tr><td>osmole&nbsp;</td><td>amount of substance (dissolved particles)&nbsp;</td><td>osm&nbsp;</td><td><code>osm</code>&nbsp;</td><td><code>OSM</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>mol</code>&nbsp;</td></tr><tr><td>pH&nbsp;</td><td>acidity&nbsp;</td><td>pH&nbsp;</td><td><code>[pH]</code>&nbsp;</td><td><code>[PH]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td><code>pH(1 mol/l)</code>&nbsp;</td></tr><tr><td>gram percent&nbsp;</td><td>mass concentration&nbsp;</td><td>g%&nbsp;</td><td><code>g%</code>&nbsp;</td><td><code>G%</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>g/dl</code>&nbsp;</td></tr><tr><td>Svedberg unit&nbsp;</td><td>sedimentation coefficient&nbsp;</td><td>S&nbsp;</td><td><code>[S]</code>&nbsp;</td><td><code>[S]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>10*-13.s</code>&nbsp;</td></tr><tr><td>high power field&nbsp;</td><td>view area in microscope&nbsp;</td><td>HPF&nbsp;</td><td><code>[HPF]</code>&nbsp;</td><td><code>[HPF]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>1</code>&nbsp;</td></tr><tr><td>low power field&nbsp;</td><td>view area in microscope&nbsp;</td><td>LPF&nbsp;</td><td><code>[LPF]</code>&nbsp;</td><td><code>[LPF]</code>&nbsp;</td><td>no</td><td>100&nbsp;</td><td><code>1</code>&nbsp;</td></tr><tr><td>katal&nbsp;</td><td>catalytic activity&nbsp;</td><td>kat&nbsp;</td><td><code>kat</code>&nbsp;</td><td><code>KAT</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>mol/s</code>&nbsp;</td></tr><tr><td>Unit&nbsp;</td><td>catalytic activity&nbsp;</td><td>U&nbsp;</td><td><code>U</code>&nbsp;</td><td><code>U</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>umol/min</code>&nbsp;</td></tr><tr><td>international unit&nbsp;</td><td>arbitrary&nbsp;</td><td>IU&nbsp;</td><td><code>[iU]</code>&nbsp;</td><td><code>[IU]</code>&nbsp;</td><td>yes</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>international unit&nbsp;</td><td>arbitrary&nbsp;</td><td>i.U.&nbsp;</td><td><code>[IU]</code>&nbsp;</td><td><code>[IU]</code>&nbsp;</td><td>yes</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>arbitrary unit&nbsp;</td><td>arbitrary&nbsp;</td><td>arb. U&nbsp;</td><td><code>[arb'U]</code>&nbsp;</td><td><code>[ARB'U]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>United States Pharmacopeia unit&nbsp;</td><td>arbitrary&nbsp;</td><td>U.S.P.&nbsp;</td><td><code>[USP'U]</code>&nbsp;</td><td><code>[USP'U]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>GPL unit&nbsp;</td><td>biologic activity of anticardiolipin IgG&nbsp;</td><td>&nbsp;</td><td><code>[GPL'U]</code>&nbsp;</td><td><code>[GPL'U]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>MPL unit&nbsp;</td><td>biologic activity of anticardiolipin IgM&nbsp;</td><td>&nbsp;</td><td><code>[MPL'U]</code>&nbsp;</td><td><code>[MPL'U]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>APL unit&nbsp;</td><td>biologic activity of anticardiolipin IgA&nbsp;</td><td>&nbsp;</td><td><code>[APL'U]</code>&nbsp;</td><td><code>[APL'U]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>Bethesda unit&nbsp;</td><td>biologic activity of factor VIII inhibitor&nbsp;</td><td>&nbsp;</td><td><code>[beth'U]</code>&nbsp;</td><td><code>[BETH'U]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>anti factor Xa unit&nbsp;</td><td>biologic activity of factor Xa inhibitor (heparin)&nbsp;</td><td>&nbsp;</td><td><code>[anti'Xa'U]</code>&nbsp;</td><td><code>[ANTI'XA'U]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>Todd unit&nbsp;</td><td>biologic activity antistreptolysin O&nbsp;</td><td>&nbsp;</td><td><code>[todd'U]</code>&nbsp;</td><td><code>[TODD'U]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>Dye unit&nbsp;</td><td>biologic activity of amylase&nbsp;</td><td>&nbsp;</td><td><code>[dye'U]</code>&nbsp;</td><td><code>[DYE'U]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>Somogyi unit&nbsp;</td><td>biologic activity of amylase&nbsp;</td><td>&nbsp;</td><td><code>[smgy'U]</code>&nbsp;</td><td><code>[SMGY'U]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>Bodansky unit&nbsp;</td><td>biologic activity of phosphatase&nbsp;</td><td>&nbsp;</td><td><code>[bdsk'U]</code>&nbsp;</td><td><code>[BDSK'U]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>King-Armstrong unit&nbsp;</td><td>biologic activity of phosphatase&nbsp;</td><td>&nbsp;</td><td><code>[ka'U]</code>&nbsp;</td><td><code>[KA'U]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>Kunkel unit&nbsp;</td><td>arbitrary biologic activity&nbsp;</td><td>&nbsp;</td><td><code>[knk'U]</code>&nbsp;</td><td><code>[KNK'U]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>Mac Lagan unit&nbsp;</td><td>arbitrary biologic activity&nbsp;</td><td>&nbsp;</td><td><code>[mclg'U]</code>&nbsp;</td><td><code>[MCLG'U]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>tuberculin unit&nbsp;</td><td>biologic activity of tuberculin&nbsp;</td><td>&nbsp;</td><td><code>[tb'U]</code>&nbsp;</td><td><code>[TB'U]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>50% cell culture infectious dose&nbsp;</td><td>biologic activity (infectivity) of an infectious agent preparation&nbsp;</td><td>CCID<emph role="sub">50</emph>&nbsp;</td><td><code>[CCID_50]</code>&nbsp;</td><td><code>[CCID_50]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>50% tissue culture infectious dose&nbsp;</td><td>biologic activity (infectivity) of an infectious agent preparation&nbsp;</td><td>TCID<emph role="sub">50</emph>&nbsp;</td><td><code>[TCID_50]</code>&nbsp;</td><td><code>[TCID_50]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>50% embryo infectious dose&nbsp;</td><td>biologic activity (infectivity) of an infectious agent preparation&nbsp;</td><td>EID<emph role="sub">50</emph>&nbsp;</td><td><code>[EID_50]</code>&nbsp;</td><td><code>[EID_50]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>plaque forming units&nbsp;</td><td>amount of an infectious agent&nbsp;</td><td>PFU&nbsp;</td><td><code>[PFU]</code>&nbsp;</td><td><code>[PFU]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>focus forming units&nbsp;</td><td>amount of an infectious agent&nbsp;</td><td>FFU&nbsp;</td><td><code>[FFU]</code>&nbsp;</td><td><code>[FFU]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>colony forming units&nbsp;</td><td>amount of a proliferating organism&nbsp;</td><td>CFU&nbsp;</td><td><code>[CFU]</code>&nbsp;</td><td><code>[CFU]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>index of reactivity&nbsp;</td><td>amount of an allergen calibrated through in-vivo testing using the Stallergenes&reg; method&nbsp;</td><td>IR&nbsp;</td><td><code>[IR]</code>&nbsp;</td><td><code>[IR]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>bioequivalent allergen unit&nbsp;</td><td>amount of an allergen calibrated through in-vivo testing based on the ID50EAL method of (intradermal dilution for 50mm sum of erythema diameters&nbsp;</td><td>BAU&nbsp;</td><td><code>[BAU]</code>&nbsp;</td><td><code>[BAU]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>allergen unit&nbsp;</td><td>procedure defined amount of an allergen using some reference standard&nbsp;</td><td>AU&nbsp;</td><td><code>[AU]</code>&nbsp;</td><td><code>[AU]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>allergen unit for Ambrosia artemisiifolia&nbsp;</td><td>procedure defined amount of the major allergen of ragweed&nbsp;</td><td>Amb a 1 U&nbsp;</td><td><code>[Amb'a'1'U]</code>&nbsp;</td><td><code>[AMB'A'1'U]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>protein nitrogen unit&nbsp;</td><td>procedure defined amount of a protein substance&nbsp;</td><td>PNU&nbsp;</td><td><code>[PNU]</code>&nbsp;</td><td><code>[PNU]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>Limit of flocculation&nbsp;</td><td>procedure defined amount of an antigen substance&nbsp;</td><td>Lf&nbsp;</td><td><code>[Lf]</code>&nbsp;</td><td><code>[LF]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>D-antigen unit&nbsp;</td><td>procedure defined amount of a poliomyelitis d-antigen substance&nbsp;</td><td>&nbsp;</td><td><code>[D'ag'U]</code>&nbsp;</td><td><code>[D'AG'U]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>fibrinogen equivalent unit&nbsp;</td><td>amount of fibrinogen broken down into the measured d-dimers&nbsp;</td><td>&nbsp;</td><td><code>[FEU]</code>&nbsp;</td><td><code>[FEU]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>ELISA unit&nbsp;</td><td>arbitrary ELISA unit&nbsp;</td><td>&nbsp;</td><td><code>[ELU]</code>&nbsp;</td><td><code>[ELU]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr><tr><td>Ehrlich unit&nbsp;</td><td>Ehrlich unit&nbsp;</td><td>&nbsp;</td><td><code>[EU]</code>&nbsp;</td><td><code>[EU]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td>&bull;&nbsp;</td></tr></table><comment><p class="comment">
            The amount of electrolytes (including acids and bases) is often
            reported as <emph>equivalents</emph> instead of amount of substance. This
            habit originates in the measuring technique of titration. <emph>The Unified Code for Units of Measure</emph>
            does not endorse using equivalents. We rather recommend to calculate
            the proper amount of substance after titration, so that
            1&nbsp;eq of Na<emph role="sup">+</emph> ions is 1&nbsp;mol, but
            1&nbsp;eq of Ca<emph role="sup">++</emph> ions is
            0.5&nbsp;mol. The problem with equivalents is that the measurement
            results are difficult to compare because their magnitude depends on
            the degree of ionization of the substance. That is to say, the meaning
            of equivalents depend not only on the substance, but also on the state
            that the substance is in. For example, in iron we have to distinguish
            Fe<emph role="sup">2+</emph> from Fe<emph role="sup">3+</emph>, so that no one can be sure how much 1&nbsp;eq
            of iron really is.
          </p><p class="comment">
            Degrees of acidity are normally measured as &ldquo;the pH value&rdquo; that is
            the negative decadic logarithmus of the concentration of free protons
            (or hydronium ions) expressed in 1&nbsp;mol/l. Usually the pH value
            is considered a dimensionless quantity. With the semantics of special
            units (<termref ref="para-21">&sect;&sect;21ff</termref>). <emph>The Unified Code for Units of Measure</emph> can link the pH value tighter to the system
            of proper units. Thus &ldquo;<code>[pH]</code>&rdquo; is defined as a unit symbol with
            the corresponding unit 1&nbsp;mol/l. This allows conversions between
            pH and concentrations, and---because <emph>The Unified Code for Units of Measure</emph> identifies the mole with
            the Avogadro number---can be converted to an absolute number of
            protons: for example, pH 7.4 converts instantly to 0.04&nbsp;&mu;mol/l
            and approximately 23975 protons per picoliter.
          </p><p class="comment">
            The unit osmol as the amount of dissolved particles is to be used with
            caution because it interferes with &ldquo;osmolar&rdquo; which is the amount of
            dissolved particles per liter.
          </p><p class="comment">
            The gram-percent (g%) is a metric unit that has the same origin as
            %vol. Originally it was a dimensionless quantity expressing a ratio of
            two masses and thus equal to 1/100&nbsp;g/g. Because water is the most
            important solvent in biochemistry and 1&nbsp;g of a solution in water
            has a volume of approximately 1&nbsp;ml, the meaning of the unit
            1&nbsp;g% drifted towards 1/100&nbsp;g/ml and farther off to
            1&nbsp;g/dl. That way, the unit 1&nbsp;g% regained a proper dimension
            (mass concentration, <emph role="emph">M</emph>/<emph role="emph">L</emph><emph role="sup">3</emph>). Most
            often it is used as 1&nbsp;mg% = 1&nbsp;mg/dl but all other SI
            prefixes are possible.
          </p><p class="comment">
            The Svedberg unit S is used to classify macromolecules (e.g.,
            ribosomes) in different phases of a centrifugate.
          </p><p class="comment">
            The units &ldquo;high power field&rdquo; (HPF) and &ldquo;low power field&rdquo; (LPF) are
            used in microscopic analysis mostly of urine sediments. These units
            are used in semi-quantitative estimations of the abundance of things
            like crystals, bacteria or red and white blood cells. The number of
            the objects of interest is counted in one view field in the microscope
            with a 10 times (low) or 100 times (high) magnifying objective lens
            and then reported as the number per LPF or per HPF
            respectively. Obviously the number of objects seen depends on the way
            the slide is prepared: the amount of emulgate dropped, its initial
            dilution, and the way the drop is smeared. These preparations of the
            slides are usually carried out with great routine but little
            exactness, hence LPF and HPF can hardly relate to any exact and
            meaningful volume.
          </p><p class="comment">
            The best we could do is to define LPF and HPF as areas of the viewed
            field. However, the area of the field varies with the kind of eyepiece
            used in the microscope. The so called &ldquo;field number&rdquo; of
            the eyepiece, i.e., the diameter of the view area is typically between
            18&nbsp;mm and 25&nbsp;mm which is divided by the magnification of the
            objective lense to yield the actual field diameter <emph>d</emph>. Because the
            area <emph>A</emph> = &pi;&nbsp;d<emph role="sup">2</emph>, the LPF can be anywhere
            between 2.5&nbsp;mm^2 and 5&nbsp;mm^2 and the HPF between
            0.025&nbsp;mm^2 and 0.05&nbsp;mm^2. Because of this inexactness, we
            define LPF and HPF as dimensionless quantities with magnitudes that
            reflect the ratio of the view areas, i.e. 100:1. This allows at least
            to convert between numbers per LPF and per HPF and vice versa.
          </p><p class="comment">
            The unit &ldquo;U&rdquo; of enzymatic activity was defined in 1964 by
            the <emph>International Union of Biochemistry</emph> as the catalytic
            activity that catalyzes the transformation of 1&nbsp;&mu;mol of the
            substrate per minute. This unit is defined so that normal biological
            enzyme activities are in the range of 1&nbsp;U-100&nbsp;U. This unit
            could not be adopted by the CGPM because it violates the style rules
            of the SI, i.e. &ldquo;unit&rdquo; is a very indistinctive word,
            &ldquo;U&rdquo; is a capital letter, and the definition is not
            coherent with the SI. 
          </p><p class="comment">
            An SI-coherent unit katal 1&nbsp;kat = 1&nbsp;mol/s, had been proposed
            for adoption into the SI over 30 years ago and was finally adopted by
            the CGPM in 1999. However, perhaps because the unit katal is 7 orders
            of magnitudes greater than normal catalytic activities, in practice
            the katal has not gained much in popularity over the unit
            &ldquo;U&rdquo;.
          </p><p class="comment">
            In its 1999 decision to add the katal to the SI, the CGPM explicitly
            &ldquo;recommends that when the katal is used, the measurand be
            specified by reference to the measurement procedure; the measurement
            procedure must identify the indicator reaction.&rdquo;  The general
            problem with catalytic activities is that these heavily depend not
            only on the substance but on many side-conditions, such as
            temperature, acidity of the solution, presence or absence of
            cofactors, inhibitors or activators, and the amount of substrate.
            Particularly a catalytic activity measured <emph>in vitro</emph> says
            little about the activity <emph>in vivo</emph>. Hence the use of katal
            alone without specifying exactly the measurement method, is not 
            sufficient to improve comparability of the measurement of catalytic 
            substances.
          </p><p class="comment">
            Because of the influence of the measurement method, results of
            biologic activity measurement cannot usually be converted. This is a
            particular problem with the many named arbitrary units that are still
            used. <emph>The Unified Code for Units of Measure</emph> initially defined all arbitrary units as
            dimensionless. But since this leads to the false conclusion that all
            arbitrary units are the same, the <emph>Unified Code for Units of Measure</emph> now accounts for arbitrary units
            using a special flag. When a unit is marked as arbitrary, it is 
            isolated from all other units, and no result can be converted from 
            and to that unit (See <termref ref="para-24">&sect;24</termref>).
          </p><p class="comment">
            The unit &ldquo;TCID<emph role="sub">50</emph>&rdquo; expresses the result of
            quantifying an infectious agent in tissue culture. It is a titer, expressing the
            highest dilution of the specimen which produces a cytopathic effect in
            50% of the cell cultures or wells inoculated.
            
            [Sources: Clinical Microbiology Reviews, July 1998, Vol. 11(3), p. 533-554]
          </p><p class="comment">
            The unit &ldquo;CCID<emph role="sub">50</emph>&rdquo; expresses the result of
            quantifying an infectious agent in a cell culture. It is a titer, expressing the
            highest dilution of the specimen which produces a cytopathic effect in
            50% of the cell cultures or wells inoculated.
            
            [Sources: Schmidt NJ. Cell culture procedures for diagnostic
            virology, p. 78-79. In Schmidt NJ, Emmons RW (ed.),
            <emph>Diagnostic procedures for viral, rickettsial and chlamydial
              infections</emph>, 5th ed. American Public Health Association, Inc.,
            Washington, D.C.]
          </p><p class="comment">
            The unit &ldquo;PFU&rdquo; measures viral infectivity in a sensitive assay in cell
            culture where the titer is determined by counting the number of
            visible plaques developed following viral infection of a sensitive
            cell culture and results recorded as PFU/ml.
          </p><p class="comment">
            The unit &ldquo;FFU&rdquo; measures viral infectivity in a sensitive
            assay in cell culture, for example, using immunofocus or vital dyes
            technology.  For example, the titer is determined by visualizing
            infected areas of a cell monolayer by probing with virus-specific
            antibodies and results are recorded as FFU/ml.
            
            [Sources: <emph>WHO expert committee on biological standardization (55th Edition).</emph> WHO Technical Report #932;]
          </p><p class="comment">
            The unit &ldquo;BAU&rdquo; measures amount of an allergen based on an in-vivo calibrated test using the Intradermal Dilution for 50mm sum of Erythema Diameters (ID50EAL) Method.
            
            [Source: <emph>Turkeltaub PC. Biological Standardization based on
              Quantitative Skin Testing - The 1D50 EAL Method. Arbeiten aus dem
              Paul-Ehrlich-Institut, dem Georg-Speyer-Haus und dem
              Ferdinand-Blum-Institut, Band 80 Gustav Fischer Verlag' Stuttgart, New
              York. 1987</emph>]
          </p><p class="comment">
            EDITORIAL NOTE: This method needs to be further investigated to
            determine a quantitative model which relates that would relate 1 BAU
            with a standardized amount of substance of the standardized allergenic
            protein. The situation is not unlike the titer and is not worse than
            for many of the arbitrary units listed already. In a future revision a
            stronger formalized metrologic model will be added to this
            specification.
          </p><p class="comment">
            The unit &ldquo;AU&rdquo; (for allergen unit) is for the amount of an
            allergen based some procedure defined and allergen specific reference
            standard. Note, do not confuse with astronomical unit, distinguish
            <code>[AU]</code> from <code>AU</code></p><p class="comment">
            The unit &ldquo;IR&rdquo; has been defined to measure the
            allergenicity of an allergen extract. The allergen extract contains
            100 IR/ml when, on a skin prick-test using a Stallerpoint&reg;, it induces
            a wheal diameter of 7 mm in 30 patients sensitized to this allergen,
            (geometric mean).  The cutaneous reactivity of these patients is
            simultaneously demonstrated by a positive skin prick-test to either 9
            % codeine phosphate or 10 mg/ml histamine. The IR unit of Stallergenes
            is not comparable to the units used by other allergen manufacturers.
          </p><p class="comment">
            EDITORIAL NOTE: Should more manufacturer specific units come up in the 
            future, we will include a manufacturer abbreviation in the unit symbol.
          </p><p class="comment">
            The unit &ldquo;Amb a 1 U&rdquo; is an arbitrary unit for the
            amount of Amb a 1, a 38 kD glycoprotein that is the major allergen in
            short ragweed (Ambrosia artemisiifolia) pollen allergen extracts. The
            amount of Amb a 1 units are determined by an in-vitro comparison of a
            test short ragweed extract to a FDA CBER Amb a 1 reference standard.
            Amb a 1 is the up-to-date term for the short ragweed pollen allergen
            that was originally described as Antigen E. They are
            synonyms. Although Antigen E is no longer used in the scientific
            literature, its meaning is unambiguous. The manufacturers are still
            licensed to use Antigen E as the designation. Therefore, Amb a 1 U =
            AgE U.  There is an empiric relationship between Amb a 1 U and BAU
            (350 Amb a 1 U/mL = 100,000 BAU/mL). It was based on studies done
            decades ago on 15 study subjects. FDA's CBER considered mandating a
            conversion to BAU/mL in the labeling of short ragweed pollen products,
            based on AgE content, but this was never implemented.  CBER provides
            two US standard reagents to manufacturers for their determination of
            Amb a 1 content, a reference standard and a reference serum. The assay
            used is a radial immunodiffusion assay (RID). Solid references
            discussing the relationship between Antigen E U/mL/Amb a 1 U/mL and
            micrograms of Antigen E U/mL/Amb a 1/mL are being researched.
          </p><p class="comment">
            EDITORIAL NOTE: The University of Texas' Structural Database of
            Allergenic Proteins (SDAP) contains close to 1000 allergens,
            isoallergens. Comparing the prospect of thousands of such special
            units for every allergen, one begins to appreciate even the
            metrologically complex BAU unit.
          </p><p class="comment">
            The unit &ldquo;PNU&rdquo; is defined as follows: 1 PNU/ml is
            equivalent to 1 x 10-5 mg of nitrogen determined to be in the material
            precipitated from 1 ml of allergenic extract by phosphotungstic acid
            (micro-Kjeldahl method). Typically, 1 mg of protein nitrogen equals
            100,000 PNU. The unit &ldquo;PNU&rdquo; is an old protein unit
            unrelated to SI units. Several hundred products, from several
            manufacturers, are labeled in PNUs, and a switch to SI units for
            protein content is impractical.
          </p><p class="comment">
            The unit &ldquo;Lf&rdquo; is called the &ldquo;Limit of
            Flocculation&rdquo; or &ldquo;limes flocculationis&rdquo;. It is based
            on an antigen-antibody precipitation reaction and used for the
            quantification of the antigenic content of tetanus and diphteria toxin
            and toxoid. The limes flocculationis is the smallest amount of antigen
            that when mixed with one unit (Ramon) of antitoxin (antibody),
            produces the most rapid floccules in the flocculation test. For a
            purified crystalline tetanus or diphteria toxin 1 Lf is equivalent to
            ~ 2 &mu;g of protein. For tetanus and diphtheria toxoids, antigenic
            purity is defined and controlled by Lf units per mg of protein
            nitrogen. 
          </p><p class="comment">
            Many sources describe the unit of antitoxin as "international unit"
            (IU), however, this is no longer correct. It was correct for the first
            international standard for antitoxin, established in 1920s. It had an
            arbitrary unit defined as IU for in vivo antitoxic activity and that
            unit was also used for establishing Lf units of toxins and toxoids,
            that is why this standard had a ratio of 1 between flocculating
            activity (Lf) and antitoxic activity (IU). When WHO replaced that
            standard in 1970s, the second international standard related to Lf by
            a factor of 1.4 instead of 1. Ultimately, WHO decided to move to the
            toxoid standards and calibrated tetanus toxoid for flocculation using
            Lf unit (not IU). With the implementation of WHO standards for
            flocculation as tetanus and diphtheria toxoids, antitoxin standards
            were discontinued by the WHO.  [Source: <emph>Lyng J. Quantitative
              Estimation of Diphtheria and Tetanus Toxoids - 4 - Toxoids as
              International Reference Materials Defining Lf-units for Diphtheria and
              Tetanus Toxoids. Biologicals (1990) 18, 11-17.</emph> Also on the
            definition of the IU for antitoxin: <emph>Spaun J, Lyng J. Replacement
              of the International Standard for Tetanus Antitoxin and the Use of the
              Standard in the Flocculation Test. Bull. Wid Hith Org. 1970, 42,
              523-534.</emph><code>http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2427455</code> and
            personal communication with FDA CBER representatives.]
          </p></comment><p name="levels"><emph role="strong"><anchor id="para-46">&sect;46</anchor> levels</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            Pseudo-units defined to express logarithms of ratios between two
            quantities of the same kind are defined in <tabref ref="levels"/>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            The meaning of the columns is declared in  <termref ref="para-43">&sect;43</termref>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
            The function pairs denoted &ldquo;<code>ln</code>&rdquo;
            &ldquo;<code>lg</code>&rdquo; and &ldquo;<code>2lg</code>&rdquo; are
            defined as the natural logarithm, the decadic logarithm, and the
            decadic logarithm times two with their respective inverse functions.
          </p><table id="levels"><tr><th>name</th><th>kind of quantity</th><th>print</th><th>c/s</th><th>c/i</th><th>M</th><th>definition value</th><th>definition unit</th></tr><caption>Levels</caption><tr><td>neper&nbsp;</td><td>level&nbsp;</td><td>Np&nbsp;</td><td><code>Np</code>&nbsp;</td><td><code>NEP</code>&nbsp;</td><td>yes</td><td>&bull;&nbsp;</td><td><code>ln(1 1)</code>&nbsp;</td></tr><tr><td>bel&nbsp;</td><td>level&nbsp;</td><td>B&nbsp;</td><td><code>B</code>&nbsp;</td><td><code>B</code>&nbsp;</td><td>yes</td><td>&bull;&nbsp;</td><td><code>lg(1 1)</code>&nbsp;</td></tr><tr><td>bel sound pressure&nbsp;</td><td>pressure level&nbsp;</td><td>B(SPL)&nbsp;</td><td><code>B[SPL]</code>&nbsp;</td><td><code>B[SPL]</code>&nbsp;</td><td>yes</td><td>&bull;&nbsp;</td><td><code>2lg(2 10*-5.Pa)</code>&nbsp;</td></tr><tr><td>bel volt&nbsp;</td><td>electric potential level&nbsp;</td><td>B(V)&nbsp;</td><td><code>B[V]</code>&nbsp;</td><td><code>B[V]</code>&nbsp;</td><td>yes</td><td>&bull;&nbsp;</td><td><code>2lg(1 V)</code>&nbsp;</td></tr><tr><td>bel millivolt&nbsp;</td><td>electric potential level&nbsp;</td><td>B(mV)&nbsp;</td><td><code>B[mV]</code>&nbsp;</td><td><code>B[MV]</code>&nbsp;</td><td>yes</td><td>&bull;&nbsp;</td><td><code>2lg(1 mV)</code>&nbsp;</td></tr><tr><td>bel microvolt&nbsp;</td><td>electric potential level&nbsp;</td><td>B(&mu;V)&nbsp;</td><td><code>B[uV]</code>&nbsp;</td><td><code>B[UV]</code>&nbsp;</td><td>yes</td><td>&bull;&nbsp;</td><td><code>2lg(1 uV)</code>&nbsp;</td></tr><tr><td>bel 10 nanovolt&nbsp;</td><td>electric potential level&nbsp;</td><td>B(10 nV)&nbsp;</td><td><code>B[10.nV]</code>&nbsp;</td><td><code>B[10.NV]</code>&nbsp;</td><td>yes</td><td>&bull;&nbsp;</td><td><code>2lg(10 nV)</code>&nbsp;</td></tr><tr><td>bel watt&nbsp;</td><td>power level&nbsp;</td><td>B(W)&nbsp;</td><td><code>B[W]</code>&nbsp;</td><td><code>B[W]</code>&nbsp;</td><td>yes</td><td>&bull;&nbsp;</td><td><code>lg(1 W)</code>&nbsp;</td></tr><tr><td>bel kilowatt&nbsp;</td><td>power level&nbsp;</td><td>B(kW)&nbsp;</td><td><code>B[kW]</code>&nbsp;</td><td><code>B[KW]</code>&nbsp;</td><td>yes</td><td>&bull;&nbsp;</td><td><code>lg(1 kW)</code>&nbsp;</td></tr></table><comment><p class="comment">
            These units are &ldquo;pseudo-units&rdquo; because of their standardized
            definition as being logarithms of a ratio of two measurements with the
            same kind-of-quantity: first, the units cancel out, and second, the
            logarithm does not produce a new unit. These units were defined as
            &ldquo;metric&rdquo; because they are used as such, although a multiplication
            operation is not defined on these quantities. Multiplication of the
            measurement value with a scalar <emph>r</emph> is equivalent to raising the
            original ratio to the <emph>r</emph>-th power.
          </p><p class="comment">
            According to NIST, the neper is used as the ratio level of field
            quantities and the bel is used for the level of power quantities. The
            factor 2 comes into play when field quantities (like electric
            potential) are expressed in decibel. The specialized bel-units B(V),
            B(mV), B(W), etc. are defined as the level of the measured quantity
            with reference quantities 1&nbsp;V, 1&nbsp;mV, and 1&nbsp;W
            respectively. [NIST Sp.&nbsp;Pub. 811, 1995 Edition]
          </p><p class="comment">
            Given the sound pressure level expressed in dB(SPL) it is feasible to
            define dB(A) for the A scale of loudness. Similar units such as phon
            and sone could be defined as well if a good approximation for the
            respective characteristic functions are available. Any advice is
            welcome.
          </p></comment><p name="miscellaneous units"><emph role="strong"><anchor id="para-47">&sect;47</anchor> miscellaneous units</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            Not otherwise classified units are defined in <tabref ref="misc"/>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            The meaning of the columns is declared in  <termref ref="para-30">&sect;30</termref>.2.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
            Only the columns titled &ldquo;c/s,&rdquo; &ldquo;c/i,&rdquo;
            &ldquo;M,&rdquo; &ldquo;value,&rdquo; and &ldquo;definition&rdquo; are
            normative. Full name and print symbol are either not standardized or
            standardized by other bodies and are out of scope of <emph>The Unified Code for Units of Measure</emph>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;4</emph></emph>
            The function pair denoted &ldquo;<code>sqrt</code>&rdquo; is defined as
            the square root with its respective inverse function, the square.
          </p><table id="misc"><tr><th>name</th><th>kind of quantity</th><th>print</th><th>c/s</th><th>c/i</th><th>M</th><th>definition value</th><th>definition unit</th></tr><caption>Miscellaneous Units</caption><tr><td>stere&nbsp;</td><td>volume&nbsp;</td><td>st&nbsp;</td><td><code>st</code>&nbsp;</td><td><code>STR</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>m3</code>&nbsp;</td></tr><tr><td>&Aring;ngstr&ouml;m&nbsp;</td><td>length&nbsp;</td><td>&Aring;&nbsp;</td><td><code>Ao</code>&nbsp;</td><td><code>AO</code>&nbsp;</td><td>no</td><td>0.1&nbsp;</td><td><code>nm</code>&nbsp;</td></tr><tr><td>barn&nbsp;</td><td>action area&nbsp;</td><td>b&nbsp;</td><td><code>b</code>&nbsp;</td><td><code>BRN</code>&nbsp;</td><td>no</td><td>100&nbsp;</td><td><code>fm2</code>&nbsp;</td></tr><tr><td>technical atmosphere&nbsp;</td><td>pressure&nbsp;</td><td>at&nbsp;</td><td><code>att</code>&nbsp;</td><td><code>ATT</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>kgf/cm2</code>&nbsp;</td></tr><tr><td>mho&nbsp;</td><td>electric conductance&nbsp;</td><td>mho&nbsp;</td><td><code>mho</code>&nbsp;</td><td><code>MHO</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>S</code>&nbsp;</td></tr><tr><td>pound per square inch&nbsp;</td><td>pressure&nbsp;</td><td>psi&nbsp;</td><td><code>[psi]</code>&nbsp;</td><td><code>[PSI]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>[lbf_av]/[in_i]2</code>&nbsp;</td></tr><tr><td>circle&nbsp;</td><td>plane angle&nbsp;</td><td>circ&nbsp;</td><td><code>circ</code>&nbsp;</td><td><code>CIRC</code>&nbsp;</td><td>no</td><td>2&nbsp;</td><td><code>[pi].rad</code>&nbsp;</td></tr><tr><td>sphere&nbsp;</td><td>solid angle&nbsp;</td><td>sph&nbsp;</td><td><code>sph</code>&nbsp;</td><td><code>SPH</code>&nbsp;</td><td>no</td><td>4&nbsp;</td><td><code>[pi].sr</code>&nbsp;</td></tr><tr><td>metric carat&nbsp;</td><td>mass&nbsp;</td><td>ct<emph role="sub">m</emph>&nbsp;</td><td><code>[car_m]</code>&nbsp;</td><td><code>[CAR_M]</code>&nbsp;</td><td>no</td><td>0.2&nbsp;</td><td><code>g</code>&nbsp;</td></tr><tr><td>carat of gold alloys&nbsp;</td><td>mass fraction&nbsp;</td><td>ct<emph role="sub"><r>Au</r></emph>&nbsp;</td><td><code>[car_Au]</code>&nbsp;</td><td><code>[CAR_AU]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>/24</code>&nbsp;</td></tr><tr><td>Smoot&nbsp;</td><td>length&nbsp;</td><td>&nbsp;</td><td><code>[smoot]</code>&nbsp;</td><td><code>[SMOOT]</code>&nbsp;</td><td>no</td><td>67&nbsp;</td><td><code>[in_i]</code>&nbsp;</td></tr><tr><td>meter per square seconds per square root of hertz&nbsp;</td><td>amplitude spectral density&nbsp;</td><td>&nbsp;</td><td><code>[m/s2/Hz^(1/2)]</code>&nbsp;</td><td><code>[M/S2/HZ^(1/2)]</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td><code>sqrt(1 m2/s4/Hz)</code>&nbsp;</td></tr><tr><td>Nephelometric Turbidity Unit&nbsp;</td><td>turbidity&nbsp;</td><td>&nbsp;</td><td><code>[NTU]</code>&nbsp;</td><td><code>[NTU]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>1</code>&nbsp;</td></tr><tr><td>Formazin Nephelometric Unit&nbsp;</td><td>turbidity&nbsp;</td><td>&nbsp;</td><td><code>[FNU]</code>&nbsp;</td><td><code>[FNU]</code>&nbsp;</td><td>no</td><td>1&nbsp;</td><td><code>1</code>&nbsp;</td></tr></table><comment><p class="comment">
            Although called &ldquo;metric carat,&rdquo; the carat really is a
            customary unit, still used for precious gems. The word carat comes
            from Greek
            &kappa;&epsilon;&rho;&alpha;&tau;&#943;&kappa;&omicron;&nu; (small
            horn) that originally was the horn-shaped grain of a locust-tree
            species in the pea family, hence the carat grain is about three barley
            grain that the other English systems of weights are based on. The arab
            carat was 1/24 of an ounce, the Imperial carat (1877) was
            205.3&nbsp;mg or 3.168&nbsp;grain. In other European cities, the carat
            was 205.8&nbsp;mg (Hamburg, Lisboa) but there were great variations
            from 188.5&nbsp;mg (Bologna) to 213.5&nbsp;mg (Torino). Due to these
            variations no customary carat has gained importance today aside from
            the &ldquo;metric carat&rdquo; defined as 200&nbsp;mg exactly. 
            [<emph>All About Carats</emph> URL:
            <code>http://www.channel1.com/users/scales/carat-def.htm</code>]
          </p><p class="comment">
            The &ldquo;Mark&rdquo; was a mass unit for precious metals (K&ouml;ln 234&nbsp;g,
            Paris 245&nbsp;g, Wien 277&nbsp;g). A mark of gold was subdivided into
            24 &ldquo;karat,&rdquo; a mark of silver into 16 &ldquo;lot.&rdquo;  This led to the other
            use of the unit &ldquo;carat&rdquo; to mean 1/24 in measuring the finesse of
            pure gold in an alloy. For example, an 8 carat gold alloy contains 8
            parts of gold on 16 parts of silver = 8/24 = 1/3, or 333 per
            mille. This carat is spelled &ldquo;karat&rdquo; in the U.S. while other
            countries do not use different spellings.
          </p><p class="comment">
            The unit &ldquo;<code>[m/s2/Hz^(1/2)]</code>&rdquo; is defined as a special unit to represent the odd fractional exponent of the second obtaining for the unit of the amplitude spectral density (ASD). It is defined based on the unit for the power spectral density (PSD), that is 1 (m/s2)<emph role="sup">2</emph>/Hz or 1 m<emph role="sup">2</emph> &middot; s<emph role="sup">-3</emph>. Since the two measurements are directly comparable, PSD = ASD<emph role="sup">2</emph>. 
          </p></comment></div2><div2><head>Prefixes and Units Used in Information Technology</head><p name="units used in information technology"><emph role="strong"><anchor id="para-48">&sect;48</anchor> units used in information technology</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            Units used in information technology are defined in table 22.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
            The meaning of the columns is declared in  <termref ref="para-43">&sect;43</termref>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
            The function pair denoted &ldquo;<code>ld</code>&rdquo; is defined as
            the dual logarithm with its respective inverse function
            <emph>f</emph><emph role="sup">-1</emph>(<emph>x</emph>) = 2<emph role="sup">x</emph>).
          </p><comment><p class="comment">
            This table is not complete. There are other units such as shannon
            (Sh), erlang (E), or hartley (Hart), for which we had no quantitative
            definitions. Any advice is appreciated.
          </p><p class="comment">
            The bit is defined twice. One definition with a subscript letter
            &lsquo;s&lsquo; is defined as the logarithmus dualis of the number of
            distinct signals. However this unit can not practically be used to
            express more than 1000 bits. Especially when the bit is used to
            express transmission rate or memory capacities, floating point
            registers would quickly overflow. Therefore we define a second symbol
            for bit, without the suffix, to be the dimensionless unit 1.
          </p><p class="comment">
            The baud (Bd) is the number of distinct signals transmitted per second,
            it is <emph>not</emph> the same as bits per second since one distinct signal
            usually carries more than one bit of information.
          </p></comment><table id="infotech"><tr><th>name</th><th>kind of quantity</th><th>print</th><th>c/s</th><th>c/i</th><th>M</th><th>definition value</th><th>definition unit</th></tr><caption>Units used in Information Science and Technology</caption><tr><td>bit&nbsp;</td><td>amount of information&nbsp;</td><td>bit<emph role="sub">s</emph>&nbsp;</td><td><code>bit_s</code>&nbsp;</td><td><code>BIT_S</code>&nbsp;</td><td>no</td><td>&bull;&nbsp;</td><td><code>ld(1 1)</code>&nbsp;</td></tr><tr><td>bit&nbsp;</td><td>amount of information&nbsp;</td><td>bit&nbsp;</td><td><code>bit</code>&nbsp;</td><td><code>BIT</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>1</code>&nbsp;</td></tr><tr><td>byte&nbsp;</td><td>amount of information&nbsp;</td><td>B&nbsp;</td><td><code>By</code>&nbsp;</td><td><code>BY</code>&nbsp;</td><td>yes</td><td>8&nbsp;</td><td><code>bit</code>&nbsp;</td></tr><tr><td>baud&nbsp;</td><td>signal transmission rate&nbsp;</td><td>Bd&nbsp;</td><td><code>Bd</code>&nbsp;</td><td><code>BD</code>&nbsp;</td><td>yes</td><td>1&nbsp;</td><td><code>/s</code>&nbsp;</td></tr></table><p id="para-pfx" name="prefixes"><emph role="strong"><anchor id="para-49">&sect;49</anchor> prefixes</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
            The prefix symbols based on powers of two for use in information
            technology as proposed by the IEEE are defined in <tabref ref="infopfx"/>.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph> 
            The meaning of the columns is declared in <termref ref="para-49">&sect;49</termref>.2.
          &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
            Only the columns titled &ldquo;c/s,&rdquo; &ldquo;c/i,&rdquo; and
            &ldquo;value,&rdquo; are normative. Full name and print symbol are out
            of scope of <emph>The Unified Code for Units of Measure</emph>.
          </p><comment><p class="comment">
            This table reflects proposed prefixes which are not yet standardized.
            [Bruce Barrow, <emph>A Lesson in Megabytes.</emph> IEEE Standards
            Bearer, January 1997]
          </p></comment><table id="infopfx"><tr><th>name</th><th>print</th><th>c/s</th><th>c/i</th><th>value</th></tr><caption>The special prefix symbols for powers of 2</caption><tr><td>kibi&nbsp;</td><td>Ki&nbsp;</td><td><code>Ki</code></td><td><code>KIB</code></td><td>1024&nbsp;</td></tr><tr><td>mebi&nbsp;</td><td>Mi&nbsp;</td><td><code>Mi</code></td><td><code>MIB</code></td><td>1048576&nbsp;</td></tr><tr><td>gibi&nbsp;</td><td>Gi&nbsp;</td><td><code>Gi</code></td><td><code>GIB</code></td><td>1073741824&nbsp;</td></tr><tr><td>tebi&nbsp;</td><td>Ti&nbsp;</td><td><code>Ti</code></td><td><code>TIB</code></td><td>1099511627776&nbsp;</td></tr></table></div2></div1></body><back><div1><head>Examples for some Non-Units.</head><p name="Non-units"><emph role="strong"><anchor id="para-50">&sect;50</anchor> Non-units</emph>
    &nbsp;&nbsp;&nbsp;
    &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;1</emph></emph>
          Symbols commonly used as units that are no real units of measurements
          are not defined by <emph>The Unified Code for Units of Measure</emph>.
        &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;2</emph></emph>
          Users are free to use curly braces expressions (<termref ref="para-12">&sect;12</termref>) if they think it is important to use symbols
          rather than the default unit <emph role="strong">1</emph>.
        &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;3</emph></emph>
          Curly braces expressions are equivalent to the unit <emph role="strong">1</emph>. The
          details of the annotations in the curly braces have no defined meaning
          in <emph>The Unified Code for Units of Measure</emph>.
        &nbsp;<emph role="strong"><emph role="sup">&nbsp;&#9632;4</emph></emph><tabref ref="junk"/> gives some example for those non-units but is not
          normative.
        </p><table id="junk"><tr><th>name</th><th>kind of quantity</th><th>print</th><th>c/s</th><th>c/i</th><th>M</th><th>definition value</th><th>definition unit</th></tr><caption>Examples for Non-Units</caption><tr><td>particles total count&nbsp;</td><td>number&nbsp;</td><td>tot.&nbsp;</td><td><code>{tot}</code>&nbsp;</td><td><code>{TOT}</code>&nbsp;</td><td>no</td><td>&nbsp;</td><td><code>1</code>&nbsp;</td></tr><tr><td>tablets&nbsp;</td><td>number&nbsp;</td><td>tbl.&nbsp;</td><td><code>{tbl}</code>&nbsp;</td><td><code>{TBL}</code>&nbsp;</td><td>no</td><td>&nbsp;</td><td><code>1</code>&nbsp;</td></tr><tr><td>red blood cell count&nbsp;</td><td>number&nbsp;</td><td>R.B.C.&nbsp;</td><td><code>{rbc}</code>&nbsp;</td><td><code>{RBC}</code>&nbsp;</td><td>no</td><td>&nbsp;</td><td><code>1</code>&nbsp;</td></tr><tr><td>gram meter per heartbeat&nbsp;</td><td>proportional to ventricular stroke work&nbsp;</td><td>g&middot; m/H.B.&nbsp;</td><td><code>g.m/{H.B.}</code>&nbsp;</td><td><code>G.M/{H.B.}</code>&nbsp;</td><td>no</td><td>&nbsp;</td><td><code>g.m</code>&nbsp;</td></tr><tr><td>gram-force meter per heartbeat&nbsp;</td><td>ventricular stroke work&nbsp;</td><td>gf&middot; m/H.B.&nbsp;</td><td><code>gf.m/{H.B.}</code>&nbsp;</td><td><code>GF.M/{H.B.}</code>&nbsp;</td><td>no</td><td>&nbsp;</td><td><code>gf.m</code>&nbsp;</td></tr><tr><td>kilogram of wet tissue&nbsp;</td><td>mass&nbsp;</td><td>kg(wet tissue)&nbsp;</td><td><code>kg{wet'tis}</code>&nbsp;</td><td><code>KG{wet'tis}</code>&nbsp;</td><td>no</td><td>&nbsp;</td><td><code>kg</code>&nbsp;</td></tr><tr><td>milligram of creatinine&nbsp;</td><td>mass&nbsp;</td><td>mg(creat.)&nbsp;</td><td><code>mg{creat}</code>&nbsp;</td><td><code>MG{creat}</code>&nbsp;</td><td>no</td><td>&nbsp;</td><td><code>mg</code>&nbsp;</td></tr></table></div1><comment><p class="comment">
        Although customarily cardiac stroke work is notated as "g.m" this is not a true unit of work. Instead one should use gram-force meter.
      </p></comment><div1><head>Summary of Conflicts</head><p><emph>The Unified Code for Units of Measure</emph> is designed and maintained so that severe name conflicts do
        not occur. However, avoiding all conflicts is possible only at the
        cost of defining very unusual symbols for those units. As the <tabref ref="conflicts"/> shows, all current conflicts are of type IVa between
        metric and nonmetric units. This means that there is only a conflict
        if the metric predicate is violated so that non-metric units are used
        with a prefix.
        
        <emph role="small"> [Schadow G, McDonald CJ et al: Units of Measure in
          Clinical Information Systems. <emph>JAMIA</emph> 6(2); Mar/Apr
          1999. p.&nbsp;151-162.]
        </emph></p><table id="conflicts"><caption>Summary of name conflicts</caption><tr><td>Gb </td><td> G-b    </td><td> Type IVa (metric-nonmetric)</td></tr><tr><td>Pa </td><td> P-a    </td><td> Type IVa (metric-nonmetric)</td></tr><tr><td>ph </td><td> p-h    </td><td> Type IVa (metric-nonmetric)</td></tr><tr><td>cd </td><td> c-d    </td><td> Type IVa (metric-nonmetric)</td></tr><tr><td>CD </td><td> C-D    </td><td> Type IVa (metric-nonmetric)</td></tr></table></div1><div1><head>Alphabetic Index</head><div2><head>Alphabetic Index By Name</head><table class="plain" border="0" cellpadding="0" cellspacing="0"><tr valign="top"><td class="small" width="47%">(retired),  homeopathic potency of centesimal series &ndash; homeopathic potency (retired) &ndash; [hp'_C]: <termref ref="para-44">&sect;44</termref><br/>(retired),  homeopathic potency of decimal series &ndash; homeopathic potency (retired) &ndash; [hp'_X]: <termref ref="para-44">&sect;44</termref><br/>(retired),  homeopathic potency of millesimal series &ndash; homeopathic potency (retired) &ndash; [hp'_M]: <termref ref="para-44">&sect;44</termref><br/>(retired),  homeopathic potency of quintamillesimal series &ndash; homeopathic potency (retired) &ndash; [hp'_Q]: <termref ref="para-44">&sect;44</termref><br/>10 nanovolt,  bel &ndash; electric potential level &ndash; B[10.nV]: <termref ref="para-46">&sect;46</termref><br/>15&nbsp;&deg;C,  calorie at &ndash; energy &ndash; cal_[15]: <termref ref="para-43">&sect;43</termref><br/>20&nbsp;&deg;C,  calorie at &ndash; energy &ndash; cal_[20]: <termref ref="para-43">&sect;43</termref><br/>39&nbsp;&deg;F,  British thermal unit at &ndash; energy &ndash; [Btu_39]: <termref ref="para-43">&sect;43</termref><br/>50% cell culture infectious dose &ndash; biologic activity (infectivity) of an infectious agent preparation &ndash; [CCID_50]: <termref ref="para-45">&sect;45</termref><br/>50% embryo infectious dose &ndash; biologic activity (infectivity) of an infectious agent preparation &ndash; [EID_50]: <termref ref="para-45">&sect;45</termref><br/>50% tissue culture infectious dose &ndash; biologic activity (infectivity) of an infectious agent preparation &ndash; [TCID_50]: <termref ref="para-45">&sect;45</termref><br/>59&nbsp;&deg;F,  British thermal unit at &ndash; energy &ndash; [Btu_59]: <termref ref="para-43">&sect;43</termref><br/>60&nbsp;&deg;F,  British thermal unit at &ndash; energy &ndash; [Btu_60]: <termref ref="para-43">&sect;43</termref><br/>APL unit &ndash; biologic activity of anticardiolipin IgA &ndash; [APL'U]: <termref ref="para-45">&sect;45</termref><br/>Ambrosia artemisiifolia,  allergen unit for &ndash; procedure defined amount of the major allergen of ragweed &ndash; [Amb'a'1'U]: <termref ref="para-45">&sect;45</termref><br/>Bethesda unit &ndash; biologic activity of factor VIII inhibitor &ndash; [beth'U]: <termref ref="para-45">&sect;45</termref><br/>Biot &ndash; electric current &ndash; Bi: <termref ref="para-33">&sect;33</termref><br/>Bodansky unit &ndash; biologic activity of phosphatase &ndash; [bdsk'U]: <termref ref="para-45">&sect;45</termref><br/>Boltzmann constant &ndash; (unclassified) &ndash; [k]: <termref ref="para-32">&sect;32</termref><br/>British hundredweight &ndash; mass &ndash; [lcwt_av]: <termref ref="para-39">&sect;39</termref><br/>British stone &ndash; mass &ndash; [stone_av]: <termref ref="para-39">&sect;39</termref><br/>British thermal unit at 39&nbsp;&deg;F &ndash; energy &ndash; [Btu_39]: <termref ref="para-43">&sect;43</termref><br/>British thermal unit at 59&nbsp;&deg;F &ndash; energy &ndash; [Btu_59]: <termref ref="para-43">&sect;43</termref><br/>British thermal unit at 60&nbsp;&deg;F &ndash; energy &ndash; [Btu_60]: <termref ref="para-43">&sect;43</termref><br/>British thermal unit &ndash; energy &ndash; [Btu]: <termref ref="para-43">&sect;43</termref><br/>British thermal unit,  international table &ndash; energy &ndash; [Btu_IT]: <termref ref="para-43">&sect;43</termref><br/>British thermal unit,  mean &ndash; energy &ndash; [Btu_m]: <termref ref="para-43">&sect;43</termref><br/>British thermal unit,  thermochemical &ndash; energy &ndash; [Btu_th]: <termref ref="para-43">&sect;43</termref><br/>British ton &ndash; mass &ndash; [lton_av]: <termref ref="para-39">&sect;39</termref><br/>Calories,  nutrition label &ndash; energy &ndash; [Cal]: <termref ref="para-43">&sect;43</termref><br/>Celsius,  degree &ndash; temperature &ndash; Cel: <termref ref="para-30">&sect;30</termref><br/>Charri&egrave;re &ndash; gauge of catheters &ndash; [Ch]: <termref ref="para-44">&sect;44</termref><br/>Curie &ndash; radioactivity &ndash; Ci: <termref ref="para-33">&sect;33</termref><br/>D-antigen unit &ndash; procedure defined amount of a poliomyelitis d-antigen substance &ndash; [D'ag'U]: <termref ref="para-45">&sect;45</termref><br/>Denier &ndash; linear mass density (of textile thread) &ndash; [den]: <termref ref="para-43">&sect;43</termref><br/>Didot's pica &ndash; length &ndash; [cicero]: <termref ref="para-42">&sect;42</termref><br/>Didot's point &ndash; length &ndash; [didot]: <termref ref="para-42">&sect;42</termref><br/>Dye unit &ndash; biologic activity of amylase &ndash; [dye'U]: <termref ref="para-45">&sect;45</termref><br/>ELISA unit &ndash; arbitrary ELISA unit &ndash; [ELU]: <termref ref="para-45">&sect;45</termref><br/>Ehrlich unit &ndash; Ehrlich unit &ndash; [EU]: <termref ref="para-45">&sect;45</termref><br/>Engineer's chain &ndash; length &ndash; [rch_us]: <termref ref="para-35">&sect;35</termref><br/>Fahrenheit,  degree &ndash; temperature &ndash; [degF]: <termref ref="para-43">&sect;43</termref><br/>Formazin Nephelometric Unit &ndash; turbidity &ndash; [FNU]: <termref ref="para-47">&sect;47</termref><br/>French foot &ndash; length &ndash; [pied]: <termref ref="para-42">&sect;42</termref><br/>French inch &ndash; length &ndash; [pouce]: <termref ref="para-42">&sect;42</termref><br/>French line &ndash; length &ndash; [ligne]: <termref ref="para-42">&sect;42</termref><br/>GPL unit &ndash; biologic activity of anticardiolipin IgG &ndash; [GPL'U]: <termref ref="para-45">&sect;45</termref><br/>Gal &ndash; acceleration &ndash; Gal: <termref ref="para-33">&sect;33</termref><br/>Gauss &ndash; magnetic flux density &ndash; G: <termref ref="para-33">&sect;33</termref><br/>Gilbert &ndash; magnetic tension &ndash; Gb: <termref ref="para-33">&sect;33</termref><br/>Gregorian month,  mean &ndash; time &ndash; mo_g: <termref ref="para-31">&sect;31</termref><br/>Gregorian year,  mean &ndash; time &ndash; a_g: <termref ref="para-31">&sect;31</termref><br/>Gunter's chain &ndash; length &ndash; [ch_br]: <termref ref="para-36">&sect;36</termref><br/>Gunter's chain &ndash; length &ndash; [ch_us]: <termref ref="para-35">&sect;35</termref><br/>Gunter's chain,  link for &ndash; length &ndash; [lk_br]: <termref ref="para-36">&sect;36</termref><br/>Gunter's chain,  link for &ndash; length &ndash; [lk_us]: <termref ref="para-35">&sect;35</termref><br/>Hounsfield unit &ndash; x-ray attenuation &ndash; [hnsf'U]: <termref ref="para-44">&sect;44</termref><br/>Julian month,  mean &ndash; time &ndash; mo_j: <termref ref="para-31">&sect;31</termref><br/>Julian year,  mean &ndash; time &ndash; a_j: <termref ref="para-31">&sect;31</termref><br/>Kayser &ndash; lineic number &ndash; Ky: <termref ref="para-33">&sect;33</termref><br/>King-Armstrong unit &ndash; biologic activity of phosphatase &ndash; [ka'U]: <termref ref="para-45">&sect;45</termref><br/>Kunkel unit &ndash; arbitrary biologic activity &ndash; [knk'U]: <termref ref="para-45">&sect;45</termref><br/>Lagan unit,  Mac &ndash; arbitrary biologic activity &ndash; [mclg'U]: <termref ref="para-45">&sect;45</termref><br/>Lambert &ndash; brightness &ndash; Lmb: <termref ref="para-33">&sect;33</termref><br/>Limit of flocculation &ndash; procedure defined amount of an antigen substance &ndash; [Lf]: <termref ref="para-45">&sect;45</termref><br/>MPL unit &ndash; biologic activity of anticardiolipin IgM &ndash; [MPL'U]: <termref ref="para-45">&sect;45</termref><br/>Mac Lagan unit &ndash; arbitrary biologic activity &ndash; [mclg'U]: <termref ref="para-45">&sect;45</termref><br/>Maxwell &ndash; flux of magnetic induction &ndash; Mx: <termref ref="para-33">&sect;33</termref><br/>Nephelometric Turbidity Unit &ndash; turbidity &ndash; [NTU]: <termref ref="para-47">&sect;47</termref><br/>Nephelometric Unit,  Formazin &ndash; turbidity &ndash; [FNU]: <termref ref="para-47">&sect;47</termref><br/>Newtonian constant of gravitation &ndash; (unclassified) &ndash; [G]: <termref ref="para-32">&sect;32</termref><br/>Oersted &ndash; magnetic field intensity &ndash; Oe: <termref ref="para-33">&sect;33</termref><br/>Pharmacopeia unit,  United States &ndash; arbitrary &ndash; [USP'U]: <termref ref="para-45">&sect;45</termref><br/>Planck constant &ndash; action &ndash; [h]: <termref ref="para-32">&sect;32</termref><br/>Poise &ndash; dynamic viscosity &ndash; P: <termref ref="para-33">&sect;33</termref><br/>Printer's pica &ndash; length &ndash; [pca_pr]: <termref ref="para-42">&sect;42</termref><br/>Printer's point &ndash; length &ndash; [pnt_pr]: <termref ref="para-42">&sect;42</termref><br/>Queen&nbsp;Anne's wine gallon &ndash; fluid volume &ndash; [gal_us]: <termref ref="para-37">&sect;37</termref><br/>Ramden's chain &ndash; length &ndash; [rch_us]: <termref ref="para-35">&sect;35</termref><br/>Ramden's chain,  link for &ndash; length &ndash; [rlk_us]: <termref ref="para-35">&sect;35</termref><br/>Rankine,  degree &ndash; temperature &ndash; [degR]: <termref ref="para-43">&sect;43</termref><br/>Roentgen &ndash; ion dose &ndash; R: <termref ref="para-33">&sect;33</termref><br/>R&eacute;aumur,  degree &ndash; temperature &ndash; [degRe]: <termref ref="para-43">&sect;43</termref><br/>Smoot &ndash; length &ndash; [smoot]: <termref ref="para-47">&sect;47</termref><br/>Somogyi unit &ndash; biologic activity of amylase &ndash; [smgy'U]: <termref ref="para-45">&sect;45</termref><br/>States Pharmacopeia unit,  United &ndash; arbitrary &ndash; [USP'U]: <termref ref="para-45">&sect;45</termref><br/>Stokes &ndash; kinematic viscosity &ndash; St: <termref ref="para-33">&sect;33</termref><br/>Surveyor's chain &ndash; length &ndash; [ch_us]: <termref ref="para-35">&sect;35</termref><br/>Svedberg unit &ndash; sedimentation coefficient &ndash; [S]: <termref ref="para-45">&sect;45</termref><br/>Todd unit &ndash; biologic activity antistreptolysin O &ndash; [todd'U]: <termref ref="para-45">&sect;45</termref><br/>Turbidity Unit,  Nephelometric &ndash; turbidity &ndash; [NTU]: <termref ref="para-47">&sect;47</termref><br/>U.S. hundredweight &ndash; mass &ndash; [scwt_av]: <termref ref="para-39">&sect;39</termref><br/>U.S. ton &ndash; mass &ndash; [ston_av]: <termref ref="para-39">&sect;39</termref><br/>Unit &ndash; catalytic activity &ndash; U: <termref ref="para-45">&sect;45</termref><br/>Unit,  Formazin Nephelometric &ndash; turbidity &ndash; [FNU]: <termref ref="para-47">&sect;47</termref><br/>Unit,  Nephelometric Turbidity &ndash; turbidity &ndash; [NTU]: <termref ref="para-47">&sect;47</termref><br/>United States Pharmacopeia unit &ndash; arbitrary &ndash; [USP'U]: <termref ref="para-45">&sect;45</termref><br/>Wood unit &ndash; fluid resistance &ndash; [wood'U]: <termref ref="para-44">&sect;44</termref><br/>Xa unit,  anti factor &ndash; biologic activity of factor Xa inhibitor (heparin) &ndash; [anti'Xa'U]: <termref ref="para-45">&sect;45</termref><br/>absorbed dose,  radiation &ndash; energy dose &ndash; RAD: <termref ref="para-33">&sect;33</termref><br/>acceleration of free fall,  standard &ndash; acceleration &ndash; [g]: <termref ref="para-32">&sect;32</termref><br/>acre &ndash; area &ndash; [acr_br]: <termref ref="para-36">&sect;36</termref><br/>acre &ndash; area &ndash; [acr_us]: <termref ref="para-35">&sect;35</termref><br/>allergen unit for Ambrosia artemisiifolia &ndash; procedure defined amount of the major allergen of ragweed &ndash; [Amb'a'1'U]: <termref ref="para-45">&sect;45</termref><br/>allergen unit &ndash; procedure defined amount of an allergen using some reference standard &ndash; [AU]: <termref ref="para-45">&sect;45</termref><br/>allergen unit,  bioequivalent &ndash; amount of an allergen calibrated through in-vivo testing based on the ID50EAL method of (intradermal dilution for 50mm sum of erythema diameters &ndash; [BAU]: <termref ref="para-45">&sect;45</termref><br/>alloys,  carat of gold &ndash; mass fraction &ndash; [car_Au]: <termref ref="para-47">&sect;47</termref><br/>amp&egrave;re &ndash; electric current &ndash; A: <termref ref="para-30">&sect;30</termref><br/>anti factor Xa unit &ndash; biologic activity of factor Xa inhibitor (heparin) &ndash; [anti'Xa'U]: <termref ref="para-45">&sect;45</termref><br/>arbitrary powers,  the number ten for &ndash; number &ndash; 10*: <termref ref="para-29">&sect;29</termref><br/>arbitrary powers,  the number ten for &ndash; number &ndash; 10^: <termref ref="para-29">&sect;29</termref><br/>arbitrary unit &ndash; arbitrary &ndash; [arb'U]: <termref ref="para-45">&sect;45</termref><br/>are &ndash; area &ndash; ar: <termref ref="para-31">&sect;31</termref><br/>artemisiifolia,  allergen unit for Ambrosia &ndash; procedure defined amount of the major allergen of ragweed &ndash; [Amb'a'1'U]: <termref ref="para-45">&sect;45</termref><br/>astronomic unit &ndash; length &ndash; AU: <termref ref="para-31">&sect;31</termref><br/>atmosphere,  standard &ndash; pressure &ndash; atm: <termref ref="para-32">&sect;32</termref><br/>atmosphere,  technical &ndash; pressure &ndash; att: <termref ref="para-47">&sect;47</termref><br/>atomic mass unit,  unified &ndash; mass &ndash; u: <termref ref="para-31">&sect;31</termref><br/>atto &ndash; prefix  &ndash; a: <termref ref="para-27">&sect;27</termref><br/>bar &ndash; pressure &ndash; bar: <termref ref="para-31">&sect;31</termref><br/>barn &ndash; action area &ndash; b: <termref ref="para-47">&sect;47</termref><br/>barrel &ndash; fluid volume &ndash; [bbl_us]: <termref ref="para-37">&sect;37</termref><br/>baud &ndash; signal transmission rate &ndash; Bd: <termref ref="para-48">&sect;48</termref><br/>becquerel &ndash; radioactivity &ndash; Bq: <termref ref="para-30">&sect;30</termref><br/>bel 10 nanovolt &ndash; electric potential level &ndash; B[10.nV]: <termref ref="para-46">&sect;46</termref><br/>bel kilowatt &ndash; power level &ndash; B[kW]: <termref ref="para-46">&sect;46</termref><br/>bel microvolt &ndash; electric potential level &ndash; B[uV]: <termref ref="para-46">&sect;46</termref><br/>bel millivolt &ndash; electric potential level &ndash; B[mV]: <termref ref="para-46">&sect;46</termref><br/>bel sound pressure &ndash; pressure level &ndash; B[SPL]: <termref ref="para-46">&sect;46</termref><br/>bel volt &ndash; electric potential level &ndash; B[V]: <termref ref="para-46">&sect;46</termref><br/>bel watt &ndash; power level &ndash; B[W]: <termref ref="para-46">&sect;46</termref><br/>bel &ndash; level &ndash; B: <termref ref="para-46">&sect;46</termref><br/>billion,  parts per &ndash; fraction &ndash; [ppb]: <termref ref="para-29">&sect;29</termref><br/>bioequivalent allergen unit &ndash; amount of an allergen calibrated through in-vivo testing based on the ID50EAL method of (intradermal dilution for 50mm sum of erythema diameters &ndash; [BAU]: <termref ref="para-45">&sect;45</termref><br/>bit &ndash; amount of information &ndash; bit: <termref ref="para-48">&sect;48</termref><br/>bit &ndash; amount of information &ndash; bit_s: <termref ref="para-48">&sect;48</termref><br/>blood cell count,  red &ndash; number &ndash; {rbc}: <termref ref="para-50">&sect;50</termref><br/>board foot &ndash; volume &ndash; [bf_i]: <termref ref="para-34">&sect;34</termref><br/>bushel &ndash; dry volume &ndash; [bu_us]: <termref ref="para-37">&sect;37</termref><br/>bushel &ndash; volume &ndash; [bu_br]: <termref ref="para-38">&sect;38</termref><br/>byte &ndash; amount of information &ndash; By: <termref ref="para-48">&sect;48</termref><br/>calorie at 15&nbsp;&deg;C &ndash; energy &ndash; cal_[15]: <termref ref="para-43">&sect;43</termref><br/>calorie at 20&nbsp;&deg;C &ndash; energy &ndash; cal_[20]: <termref ref="para-43">&sect;43</termref><br/>calorie &ndash; energy &ndash; cal: <termref ref="para-43">&sect;43</termref><br/>calorie,  international table &ndash; energy &ndash; cal_IT: <termref ref="para-43">&sect;43</termref><br/>calorie,  mean &ndash; energy &ndash; cal_m: <termref ref="para-43">&sect;43</termref><br/>calorie,  thermochemical &ndash; energy &ndash; cal_th: <termref ref="para-43">&sect;43</termref><br/>candela &ndash; luminous intensity &ndash; cd: <termref ref="para-28">&sect;28</termref><br/>carat of gold alloys &ndash; mass fraction &ndash; [car_Au]: <termref ref="para-47">&sect;47</termref><br/>carat,  metric &ndash; mass &ndash; [car_m]: <termref ref="para-47">&sect;47</termref><br/>cell count,  red blood &ndash; number &ndash; {rbc}: <termref ref="para-50">&sect;50</termref><br/>cell culture infectious dose,  50% &ndash; biologic activity (infectivity) of an infectious agent preparation &ndash; [CCID_50]: <termref ref="para-45">&sect;45</termref><br/>centesimal hahnemannian series,  homeopathic potency of &ndash; homeopathic potency (Hahnemann) &ndash; [hp_C]: <termref ref="para-44">&sect;44</termref><br/>centesimal korsakovian series,  homeopathic potency of &ndash; homeopathic potency (Korsakov) &ndash; [kp_C]: <termref ref="para-44">&sect;44</termref><br/>centesimal series (retired),  homeopathic potency of &ndash; homeopathic potency (retired) &ndash; [hp'_C]: <termref ref="para-44">&sect;44</termref><br/>centi &ndash; prefix  &ndash; c: <termref ref="para-27">&sect;27</termref><br/>chain,  Engineer's &ndash; length &ndash; [rch_us]: <termref ref="para-35">&sect;35</termref><br/>chain,  Gunter's &ndash; length &ndash; [ch_br]: <termref ref="para-36">&sect;36</termref><br/>chain,  Gunter's &ndash; length &ndash; [ch_us]: <termref ref="para-35">&sect;35</termref><br/>chain,  Ramden's &ndash; length &ndash; [rch_us]: <termref ref="para-35">&sect;35</termref><br/>chain,  Surveyor's &ndash; length &ndash; [ch_us]: <termref ref="para-35">&sect;35</termref><br/>chain,  link for Gunter's &ndash; length &ndash; [lk_br]: <termref ref="para-36">&sect;36</termref><br/>chain,  link for Gunter's &ndash; length &ndash; [lk_us]: <termref ref="para-35">&sect;35</termref><br/>chain,  link for Ramden's &ndash; length &ndash; [rlk_us]: <termref ref="para-35">&sect;35</termref><br/>charge,  elementary &ndash; electric charge &ndash; [e]: <termref ref="para-32">&sect;32</termref><br/>cicero &ndash; length &ndash; [cicero]: <termref ref="para-42">&sect;42</termref><br/>circle &ndash; plane angle &ndash; circ: <termref ref="para-47">&sect;47</termref><br/>circular mil &ndash; area &ndash; [cml_i]: <termref ref="para-34">&sect;34</termref><br/>colony forming units &ndash; amount of a proliferating organism &ndash; [CFU]: <termref ref="para-45">&sect;45</termref><br/>column,  inch of mercury &ndash; pressure &ndash; [in_i'Hg]: <termref ref="para-44">&sect;44</termref><br/>column,  inch of water &ndash; pressure &ndash; [in_i'H2O]: <termref ref="para-44">&sect;44</termref><br/>column,  meter of mercury &ndash; pressure &ndash; m[Hg]: <termref ref="para-44">&sect;44</termref><br/>column,  meter of water &ndash; pressure &ndash; m[H2O]: <termref ref="para-44">&sect;44</termref><br/>constant of gravitation,  Newtonian &ndash; (unclassified) &ndash; [G]: <termref ref="para-32">&sect;32</termref><br/>constant,  Boltzmann &ndash; (unclassified) &ndash; [k]: <termref ref="para-32">&sect;32</termref><br/>constant,  Planck &ndash; action &ndash; [h]: <termref ref="para-32">&sect;32</termref><br/>cord &ndash; fluid volume &ndash; [crd_us]: <termref ref="para-37">&sect;37</termref><br/>cord &ndash; volume &ndash; [cr_i]: <termref ref="para-34">&sect;34</termref><br/>coulomb &ndash; electric charge &ndash; C: <termref ref="para-28">&sect;28</termref><br/>count,  particles total &ndash; number &ndash; {tot}: <termref ref="para-50">&sect;50</termref><br/>count,  red blood cell &ndash; number &ndash; {rbc}: <termref ref="para-50">&sect;50</termref><br/>creatinine,  milligram of &ndash; mass &ndash; mg{creat}: <termref ref="para-50">&sect;50</termref><br/>cubic foot &ndash; volume &ndash; [cft_i]: <termref ref="para-34">&sect;34</termref><br/>cubic inch &ndash; volume &ndash; [cin_i]: <termref ref="para-34">&sect;34</termref><br/>cubic yard &ndash; volume &ndash; [cyd_i]: <termref ref="para-34">&sect;34</termref><br/>culture infectious dose,  50% cell &ndash; biologic activity (infectivity) of an infectious agent preparation &ndash; [CCID_50]: <termref ref="para-45">&sect;45</termref><br/>culture infectious dose,  50% tissue &ndash; biologic activity (infectivity) of an infectious agent preparation &ndash; [TCID_50]: <termref ref="para-45">&sect;45</termref><br/>cup &ndash; volume &ndash; [cup_us]: <termref ref="para-37">&sect;37</termref><br/>cup,  metric &ndash; volume &ndash; [cup_m]: <termref ref="para-37">&sect;37</termref><br/>day &ndash; time &ndash; d: <termref ref="para-31">&sect;31</termref><br/>deci &ndash; prefix  &ndash; d: <termref ref="para-27">&sect;27</termref><br/>decimal hahnemannian series,  homeopathic potency of &ndash; homeopathic potency (Hahnemann) &ndash; [hp_X]: <termref ref="para-44">&sect;44</termref><br/>decimal korsakovian series,  homeopathic potency of &ndash; homeopathic potency (Korsakov) &ndash; [kp_X]: <termref ref="para-44">&sect;44</termref><br/>decimal series (retired),  homeopathic potency of &ndash; homeopathic potency (retired) &ndash; [hp'_X]: <termref ref="para-44">&sect;44</termref><br/>degree Celsius &ndash; temperature &ndash; Cel: <termref ref="para-30">&sect;30</termref><br/>degree Fahrenheit &ndash; temperature &ndash; [degF]: <termref ref="para-43">&sect;43</termref><br/>degree Rankine &ndash; temperature &ndash; [degR]: <termref ref="para-43">&sect;43</termref><br/>degree R&eacute;aumur &ndash; temperature &ndash; [degRe]: <termref ref="para-43">&sect;43</termref><br/>degree &ndash; plane angle &ndash; deg: <termref ref="para-31">&sect;31</termref><br/>deka &ndash; prefix  &ndash; da: <termref ref="para-27">&sect;27</termref><br/>didot &ndash; length &ndash; [didot]: <termref ref="para-42">&sect;42</termref><br/>diopter &ndash; refraction of a lens &ndash; [diop]: <termref ref="para-44">&sect;44</termref><br/>diopter,  prism &ndash; refraction of a prism &ndash; [p'diop]: <termref ref="para-44">&sect;44</termref><br/>dose,  50% cell culture infectious &ndash; biologic activity (infectivity) of an infectious agent preparation &ndash; [CCID_50]: <termref ref="para-45">&sect;45</termref><br/>dose,  50% embryo infectious &ndash; biologic activity (infectivity) of an infectious agent preparation &ndash; [EID_50]: <termref ref="para-45">&sect;45</termref><br/>dose,  50% tissue culture infectious &ndash; biologic activity (infectivity) of an infectious agent preparation &ndash; [TCID_50]: <termref ref="para-45">&sect;45</termref><br/>dose,  radiation absorbed &ndash; energy dose &ndash; RAD: <termref ref="para-33">&sect;33</termref><br/>drachm &ndash; mass &ndash; [dr_ap]: <termref ref="para-41">&sect;41</termref><br/>dram &ndash; mass &ndash; [dr_ap]: <termref ref="para-41">&sect;41</termref><br/>dram &ndash; mass &ndash; [dr_av]: <termref ref="para-39">&sect;39</termref><br/>dram,  fluid &ndash; fluid volume &ndash; [fdr_us]: <termref ref="para-37">&sect;37</termref><br/>dram,  fluid &ndash; volume &ndash; [fdr_br]: <termref ref="para-38">&sect;38</termref><br/>drop &ndash; volume &ndash; [drp]: <termref ref="para-44">&sect;44</termref><br/>dry pint &ndash; dry volume &ndash; [dpt_us]: <termref ref="para-37">&sect;37</termref><br/>dry quart &ndash; dry volume &ndash; [dqt_us]: <termref ref="para-37">&sect;37</termref><br/>dyne &ndash; force &ndash; dyn: <termref ref="para-33">&sect;33</termref><br/>electron mass &ndash; mass &ndash; [m_e]: <termref ref="para-32">&sect;32</termref><br/>electronvolt &ndash; energy &ndash; eV: <termref ref="para-31">&sect;31</termref><br/>elementary charge &ndash; electric charge &ndash; [e]: <termref ref="para-32">&sect;32</termref><br/>embryo infectious dose,  50% &ndash; biologic activity (infectivity) of an infectious agent preparation &ndash; [EID_50]: <termref ref="para-45">&sect;45</termref><br/>equivalent man,  radiation &ndash; dose equivalent &ndash; REM: <termref ref="para-33">&sect;33</termref><br/>equivalent unit,  fibrinogen &ndash; amount of fibrinogen broken down into the measured d-dimers &ndash; [FEU]: <termref ref="para-45">&sect;45</termref><br/>equivalent,  metabolic &ndash; metabolic cost of physical activity &ndash; [MET]: <termref ref="para-44">&sect;44</termref><br/>equivalents &ndash; amount of substance &ndash; eq: <termref ref="para-45">&sect;45</termref><br/>erg &ndash; energy &ndash; erg: <termref ref="para-33">&sect;33</termref><br/>exa &ndash; prefix  &ndash; E: <termref ref="para-27">&sect;27</termref><br/>factor Xa unit,  anti &ndash; biologic activity of factor Xa inhibitor (heparin) &ndash; [anti'Xa'U]: <termref ref="para-45">&sect;45</termref><br/>fall,  standard acceleration of free &ndash; acceleration &ndash; [g]: <termref ref="para-32">&sect;32</termref><br/>farad &ndash; electric capacitance &ndash; F: <termref ref="para-30">&sect;30</termref><br/>fathom &ndash; depth of water &ndash; [fth_i]: <termref ref="para-34">&sect;34</termref><br/>fathom &ndash; length &ndash; [fth_br]: <termref ref="para-36">&sect;36</termref><br/>fathom &ndash; length &ndash; [fth_us]: <termref ref="para-35">&sect;35</termref><br/>femto &ndash; prefix  &ndash; f: <termref ref="para-27">&sect;27</termref><br/>fibrinogen equivalent unit &ndash; amount of fibrinogen broken down into the measured d-dimers &ndash; [FEU]: <termref ref="para-45">&sect;45</termref><br/>field,  high power &ndash; view area in microscope &ndash; [HPF]: <termref ref="para-45">&sect;45</termref><br/>field,  low power &ndash; view area in microscope &ndash; [LPF]: <termref ref="para-45">&sect;45</termref><br/>flocculation,  Limit of &ndash; procedure defined amount of an antigen substance &ndash; [Lf]: <termref ref="para-45">&sect;45</termref><br/>fluid dram &ndash; fluid volume &ndash; [fdr_us]: <termref ref="para-37">&sect;37</termref><br/>fluid dram &ndash; volume &ndash; [fdr_br]: <termref ref="para-38">&sect;38</termref><br/>fluid ounce &ndash; fluid volume &ndash; [foz_us]: <termref ref="para-37">&sect;37</termref><br/>fluid ounce &ndash; volume &ndash; [foz_br]: <termref ref="para-38">&sect;38</termref><br/>fluid ounce,  metric &ndash; fluid volume &ndash; [foz_m]: <termref ref="para-37">&sect;37</termref><br/>focus forming units &ndash; amount of an infectious agent &ndash; [FFU]: <termref ref="para-45">&sect;45</termref><br/>foot &ndash; length &ndash; [ft_br]: <termref ref="para-36">&sect;36</termref><br/>foot &ndash; length &ndash; [ft_i]: <termref ref="para-34">&sect;34</termref><br/>foot &ndash; length &ndash; [ft_us]: <termref ref="para-35">&sect;35</termref><br/>foot,  French &ndash; length &ndash; [pied]: <termref ref="para-42">&sect;42</termref><br/>foot,  board &ndash; volume &ndash; [bf_i]: <termref ref="para-34">&sect;34</termref><br/>foot,  cubic &ndash; volume &ndash; [cft_i]: <termref ref="para-34">&sect;34</termref><br/>foot,  square &ndash; area &ndash; [sft_i]: <termref ref="para-34">&sect;34</termref><br/>force,  pound &ndash; force &ndash; [lbf_av]: <termref ref="para-32">&sect;32</termref><br/>forming units,  colony &ndash; amount of a proliferating organism &ndash; [CFU]: <termref ref="para-45">&sect;45</termref><br/>forming units,  focus &ndash; amount of an infectious agent &ndash; [FFU]: <termref ref="para-45">&sect;45</termref><br/>forming units,  plaque &ndash; amount of an infectious agent &ndash; [PFU]: <termref ref="para-45">&sect;45</termref><br/>free fall,  standard acceleration of &ndash; acceleration &ndash; [g]: <termref ref="para-32">&sect;32</termref><br/>french &ndash; gauge of catheters &ndash; [Ch]: <termref ref="para-44">&sect;44</termref><br/>furlong &ndash; length &ndash; [fur_us]: <termref ref="para-35">&sect;35</termref><br/>gallon &ndash; volume &ndash; [gal_br]: <termref ref="para-38">&sect;38</termref><br/>gallon,  Queen&nbsp;Anne's wine &ndash; fluid volume &ndash; [gal_us]: <termref ref="para-37">&sect;37</termref><br/>gallon,  historical winchester &ndash; dry volume &ndash; [gal_wi]: <termref ref="para-37">&sect;37</termref><br/>gibi &ndash; prefix  &ndash; Gi: <termref ref="para-49">&sect;49</termref><br/>giga &ndash; prefix  &ndash; G: <termref ref="para-27">&sect;27</termref><br/>gill &ndash; fluid volume &ndash; [gil_us]: <termref ref="para-37">&sect;37</termref><br/>gill &ndash; volume &ndash; [gil_br]: <termref ref="para-38">&sect;38</termref><br/>gold alloys,  carat of &ndash; mass fraction &ndash; [car_Au]: <termref ref="para-47">&sect;47</termref><br/>gon &ndash; plane angle &ndash; gon: <termref ref="para-31">&sect;31</termref><br/>grade &ndash; plane angle &ndash; gon: <termref ref="para-31">&sect;31</termref><br/>grain &ndash; mass &ndash; [gr]: <termref ref="para-39">&sect;39</termref><br/>gram meter per heartbeat &ndash; proportional to ventricular stroke work &ndash; g.m/{H.B.}: <termref ref="para-50">&sect;50</termref><br/>gram percent &ndash; mass concentration &ndash; g%: <termref ref="para-45">&sect;45</termref><br/>gram &ndash; mass &ndash; g: <termref ref="para-28">&sect;28</termref><br/>gram-force meter per heartbeat &ndash; ventricular stroke work &ndash; gf.m/{H.B.}: <termref ref="para-50">&sect;50</termref><br/>gram-force &ndash; force &ndash; gf: <termref ref="para-32">&sect;32</termref><br/>gravitation,  Newtonian constant of &ndash; (unclassified) &ndash; [G]: <termref ref="para-32">&sect;32</termref><br/>gray &ndash; energy dose &ndash; Gy: <termref ref="para-30">&sect;30</termref><br/>hahnemannian series,  homeopathic potency of centesimal &ndash; homeopathic potency (Hahnemann) &ndash; [hp_C]: <termref ref="para-44">&sect;44</termref><br/>hahnemannian series,  homeopathic potency of decimal &ndash; homeopathic potency (Hahnemann) &ndash; [hp_X]: <termref ref="para-44">&sect;44</termref><br/>hahnemannian series,  homeopathic potency of millesimal &ndash; homeopathic potency (Hahnemann) &ndash; [hp_M]: <termref ref="para-44">&sect;44</termref><br/>hahnemannian series,  homeopathic potency of quintamillesimal &ndash; homeopathic potency (Hahnemann) &ndash; [hp_Q]: <termref ref="para-44">&sect;44</termref><br/>hand &ndash; height of horses &ndash; [hd_i]: <termref ref="para-34">&sect;34</termref><br/>heartbeat,  gram meter per &ndash; proportional to ventricular stroke work &ndash; g.m/{H.B.}: <termref ref="para-50">&sect;50</termref><br/>heartbeat,  gram-force meter per &ndash; ventricular stroke work &ndash; gf.m/{H.B.}: <termref ref="para-50">&sect;50</termref><br/>hecto &ndash; prefix  &ndash; h: <termref ref="para-27">&sect;27</termref><br/>henry &ndash; inductance &ndash; H: <termref ref="para-30">&sect;30</termref><br/>hertz &ndash; frequency &ndash; Hz: <termref ref="para-30">&sect;30</termref><br/>hertz,  meter per square seconds per square root of &ndash; amplitude spectral density &ndash; [m/s2/Hz^(1/2)]: <termref ref="para-47">&sect;47</termref><br/>high power field &ndash; view area in microscope &ndash; [HPF]: <termref ref="para-45">&sect;45</termref><br/>historical winchester gallon &ndash; dry volume &ndash; [gal_wi]: <termref ref="para-37">&sect;37</termref><br/>homeopathic potency of centesimal hahnemannian series &ndash; homeopathic potency (Hahnemann) &ndash; [hp_C]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency of centesimal korsakovian series &ndash; homeopathic potency (Korsakov) &ndash; [kp_C]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency of centesimal series (retired) &ndash; homeopathic potency (retired) &ndash; [hp'_C]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency of decimal hahnemannian series &ndash; homeopathic potency (Hahnemann) &ndash; [hp_X]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency of decimal korsakovian series &ndash; homeopathic potency (Korsakov) &ndash; [kp_X]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency of decimal series (retired) &ndash; homeopathic potency (retired) &ndash; [hp'_X]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency of millesimal hahnemannian series &ndash; homeopathic potency (Hahnemann) &ndash; [hp_M]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency of millesimal korsakovian series &ndash; homeopathic potency (Korsakov) &ndash; [kp_M]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency of millesimal series (retired) &ndash; homeopathic potency (retired) &ndash; [hp'_M]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency of quintamillesimal hahnemannian series &ndash; homeopathic potency (Hahnemann) &ndash; [hp_Q]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency of quintamillesimal korsakovian series &ndash; homeopathic potency (Korsakov) &ndash; [kp_Q]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency of quintamillesimal series (retired) &ndash; homeopathic potency (retired) &ndash; [hp'_Q]: <termref ref="para-44">&sect;44</termref><br/>horsepower &ndash; power &ndash; [HP]: <termref ref="para-43">&sect;43</termref><br/>hour &ndash; time &ndash; h: <termref ref="para-31">&sect;31</termref><br/>hundredweight,  British &ndash; mass &ndash; [lcwt_av]: <termref ref="para-39">&sect;39</termref><br/>hundredweight,  U.S. &ndash; mass &ndash; [scwt_av]: <termref ref="para-39">&sect;39</termref><br/>hundredweight,  long &ndash; mass &ndash; [lcwt_av]: <termref ref="para-39">&sect;39</termref><br/>hundredweight,  short &ndash; mass &ndash; [scwt_av]: <termref ref="para-39">&sect;39</termref><br/>inch of mercury column &ndash; pressure &ndash; [in_i'Hg]: <termref ref="para-44">&sect;44</termref><br/>inch of water column &ndash; pressure &ndash; [in_i'H2O]: <termref ref="para-44">&sect;44</termref><br/>inch &ndash; length &ndash; [in_br]: <termref ref="para-36">&sect;36</termref><br/>inch &ndash; length &ndash; [in_i]: <termref ref="para-34">&sect;34</termref><br/>inch &ndash; length &ndash; [in_us]: <termref ref="para-35">&sect;35</termref><br/>inch,  French &ndash; length &ndash; [pouce]: <termref ref="para-42">&sect;42</termref><br/>inch,  cubic &ndash; volume &ndash; [cin_i]: <termref ref="para-34">&sect;34</termref><br/>inch,  pound per square &ndash; pressure &ndash; [psi]: <termref ref="para-47">&sect;47</termref><br/>inch,  square &ndash; area &ndash; [sin_i]: <termref ref="para-34">&sect;34</termref><br/>index of reactivity &ndash; amount of an allergen calibrated through in-vivo testing using the Stallergenes&reg; method &ndash; [IR]: <termref ref="para-45">&sect;45</termref><br/>infectious dose,  50% cell culture &ndash; biologic activity (infectivity) of an infectious agent preparation &ndash; [CCID_50]: <termref ref="para-45">&sect;45</termref><br/>infectious dose,  50% embryo &ndash; biologic activity (infectivity) of an infectious agent preparation &ndash; [EID_50]: <termref ref="para-45">&sect;45</termref><br/>infectious dose,  50% tissue culture &ndash; biologic activity (infectivity) of an infectious agent preparation &ndash; [TCID_50]: <termref ref="para-45">&sect;45</termref><br/>international table British thermal unit &ndash; energy &ndash; [Btu_IT]: <termref ref="para-43">&sect;43</termref><br/>international table calorie &ndash; energy &ndash; cal_IT: <termref ref="para-43">&sect;43</termref><br/>international unit &ndash; arbitrary &ndash; [IU]: <termref ref="para-45">&sect;45</termref><br/>international unit &ndash; arbitrary &ndash; [iU]: <termref ref="para-45">&sect;45</termref><br/>joule &ndash; energy &ndash; J: <termref ref="para-30">&sect;30</termref><br/>katal &ndash; catalytic activity &ndash; kat: <termref ref="para-45">&sect;45</termref><br/>kelvin &ndash; temperature &ndash; K: <termref ref="para-28">&sect;28</termref><br/>kibi &ndash; prefix  &ndash; Ki: <termref ref="para-49">&sect;49</termref><br/>kilo &ndash; prefix  &ndash; k: <termref ref="para-27">&sect;27</termref><br/>kilogram of wet tissue &ndash; mass &ndash; kg{wet'tis}: <termref ref="para-50">&sect;50</termref><br/>kilowatt,  bel &ndash; power level &ndash; B[kW]: <termref ref="para-46">&sect;46</termref><br/></td><td class="small" width="6%">&nbsp;&nbsp;&nbsp;</td><td class="small" width="47%">knot &ndash; velocity &ndash; [kn_br]: <termref ref="para-36">&sect;36</termref><br/>knot &ndash; velocity &ndash; [kn_i]: <termref ref="para-34">&sect;34</termref><br/>korsakovian series,  homeopathic potency of centesimal &ndash; homeopathic potency (Korsakov) &ndash; [kp_C]: <termref ref="para-44">&sect;44</termref><br/>korsakovian series,  homeopathic potency of decimal &ndash; homeopathic potency (Korsakov) &ndash; [kp_X]: <termref ref="para-44">&sect;44</termref><br/>korsakovian series,  homeopathic potency of millesimal &ndash; homeopathic potency (Korsakov) &ndash; [kp_M]: <termref ref="para-44">&sect;44</termref><br/>korsakovian series,  homeopathic potency of quintamillesimal &ndash; homeopathic potency (Korsakov) &ndash; [kp_Q]: <termref ref="para-44">&sect;44</termref><br/>label Calories,  nutrition &ndash; energy &ndash; [Cal]: <termref ref="para-43">&sect;43</termref><br/>light,  velocity of &ndash; velocity &ndash; [c]: <termref ref="para-32">&sect;32</termref><br/>light-year &ndash; length &ndash; [ly]: <termref ref="para-32">&sect;32</termref><br/>ligne &ndash; length &ndash; [ligne]: <termref ref="para-42">&sect;42</termref><br/>line &ndash; length &ndash; [lne]: <termref ref="para-42">&sect;42</termref><br/>line,  French &ndash; length &ndash; [ligne]: <termref ref="para-42">&sect;42</termref><br/>link for Gunter's chain &ndash; length &ndash; [lk_br]: <termref ref="para-36">&sect;36</termref><br/>link for Gunter's chain &ndash; length &ndash; [lk_us]: <termref ref="para-35">&sect;35</termref><br/>link for Ramden's chain &ndash; length &ndash; [rlk_us]: <termref ref="para-35">&sect;35</termref><br/>liter &ndash; volume &ndash; L: <termref ref="para-31">&sect;31</termref><br/>liter &ndash; volume &ndash; l: <termref ref="para-31">&sect;31</termref><br/>long hundredweight &ndash; mass &ndash; [lcwt_av]: <termref ref="para-39">&sect;39</termref><br/>long ton &ndash; mass &ndash; [lton_av]: <termref ref="para-39">&sect;39</termref><br/>low power field &ndash; view area in microscope &ndash; [LPF]: <termref ref="para-45">&sect;45</termref><br/>lumen &ndash; luminous flux &ndash; lm: <termref ref="para-30">&sect;30</termref><br/>lux &ndash; illuminance &ndash; lx: <termref ref="para-30">&sect;30</termref><br/>man,  radiation equivalent &ndash; dose equivalent &ndash; REM: <termref ref="para-33">&sect;33</termref><br/>mass unit,  unified atomic &ndash; mass &ndash; u: <termref ref="para-31">&sect;31</termref><br/>mass,  electron &ndash; mass &ndash; [m_e]: <termref ref="para-32">&sect;32</termref><br/>mass,  proton &ndash; mass &ndash; [m_p]: <termref ref="para-32">&sect;32</termref><br/>mean British thermal unit &ndash; energy &ndash; [Btu_m]: <termref ref="para-43">&sect;43</termref><br/>mean Gregorian month &ndash; time &ndash; mo_g: <termref ref="para-31">&sect;31</termref><br/>mean Gregorian year &ndash; time &ndash; a_g: <termref ref="para-31">&sect;31</termref><br/>mean Julian month &ndash; time &ndash; mo_j: <termref ref="para-31">&sect;31</termref><br/>mean Julian year &ndash; time &ndash; a_j: <termref ref="para-31">&sect;31</termref><br/>mean calorie &ndash; energy &ndash; cal_m: <termref ref="para-43">&sect;43</termref><br/>mebi &ndash; prefix  &ndash; Mi: <termref ref="para-49">&sect;49</termref><br/>mega &ndash; prefix  &ndash; M: <termref ref="para-27">&sect;27</termref><br/>mercury column,  inch of &ndash; pressure &ndash; [in_i'Hg]: <termref ref="para-44">&sect;44</termref><br/>mercury column,  meter of &ndash; pressure &ndash; m[Hg]: <termref ref="para-44">&sect;44</termref><br/>mesh &ndash; lineic number &ndash; [mesh_i]: <termref ref="para-44">&sect;44</termref><br/>metabolic equivalent &ndash; metabolic cost of physical activity &ndash; [MET]: <termref ref="para-44">&sect;44</termref><br/>meter of mercury column &ndash; pressure &ndash; m[Hg]: <termref ref="para-44">&sect;44</termref><br/>meter of water column &ndash; pressure &ndash; m[H2O]: <termref ref="para-44">&sect;44</termref><br/>meter per heartbeat,  gram &ndash; proportional to ventricular stroke work &ndash; g.m/{H.B.}: <termref ref="para-50">&sect;50</termref><br/>meter per heartbeat,  gram-force &ndash; ventricular stroke work &ndash; gf.m/{H.B.}: <termref ref="para-50">&sect;50</termref><br/>meter per square seconds per square root of hertz &ndash; amplitude spectral density &ndash; [m/s2/Hz^(1/2)]: <termref ref="para-47">&sect;47</termref><br/>meter &ndash; length &ndash; m: <termref ref="para-28">&sect;28</termref><br/>metric carat &ndash; mass &ndash; [car_m]: <termref ref="para-47">&sect;47</termref><br/>metric cup &ndash; volume &ndash; [cup_m]: <termref ref="para-37">&sect;37</termref><br/>metric fluid ounce &ndash; fluid volume &ndash; [foz_m]: <termref ref="para-37">&sect;37</termref><br/>metric ounce &ndash; mass &ndash; [oz_m]: <termref ref="para-41">&sect;41</termref><br/>metric tablespoon &ndash; volume &ndash; [tbs_m]: <termref ref="para-37">&sect;37</termref><br/>metric teaspoon &ndash; volume &ndash; [tsp_m]: <termref ref="para-37">&sect;37</termref><br/>mho &ndash; electric conductance &ndash; mho: <termref ref="para-47">&sect;47</termref><br/>micro &ndash; prefix  &ndash; u: <termref ref="para-27">&sect;27</termref><br/>microvolt,  bel &ndash; electric potential level &ndash; B[uV]: <termref ref="para-46">&sect;46</termref><br/>mil &ndash; length &ndash; [mil_i]: <termref ref="para-34">&sect;34</termref><br/>mil &ndash; length &ndash; [mil_us]: <termref ref="para-35">&sect;35</termref><br/>mil,  circular &ndash; area &ndash; [cml_i]: <termref ref="para-34">&sect;34</termref><br/>mile &ndash; length &ndash; [mi_br]: <termref ref="para-36">&sect;36</termref><br/>mile &ndash; length &ndash; [mi_i]: <termref ref="para-34">&sect;34</termref><br/>mile &ndash; length &ndash; [mi_us]: <termref ref="para-35">&sect;35</termref><br/>mile,  nautical &ndash; length &ndash; [nmi_br]: <termref ref="para-36">&sect;36</termref><br/>mile,  nautical &ndash; length &ndash; [nmi_i]: <termref ref="para-34">&sect;34</termref><br/>mile,  square &ndash; area &ndash; [smi_us]: <termref ref="para-35">&sect;35</termref><br/>millesimal hahnemannian series,  homeopathic potency of &ndash; homeopathic potency (Hahnemann) &ndash; [hp_M]: <termref ref="para-44">&sect;44</termref><br/>millesimal korsakovian series,  homeopathic potency of &ndash; homeopathic potency (Korsakov) &ndash; [kp_M]: <termref ref="para-44">&sect;44</termref><br/>millesimal series (retired),  homeopathic potency of &ndash; homeopathic potency (retired) &ndash; [hp'_M]: <termref ref="para-44">&sect;44</termref><br/>milli &ndash; prefix  &ndash; m: <termref ref="para-27">&sect;27</termref><br/>milligram of creatinine &ndash; mass &ndash; mg{creat}: <termref ref="para-50">&sect;50</termref><br/>million,  parts per &ndash; fraction &ndash; [ppm]: <termref ref="para-29">&sect;29</termref><br/>millivolt,  bel &ndash; electric potential level &ndash; B[mV]: <termref ref="para-46">&sect;46</termref><br/>minim &ndash; fluid volume &ndash; [min_us]: <termref ref="para-37">&sect;37</termref><br/>minim &ndash; volume &ndash; [min_br]: <termref ref="para-38">&sect;38</termref><br/>minute &ndash; plane angle &ndash; ': <termref ref="para-31">&sect;31</termref><br/>minute &ndash; time &ndash; min: <termref ref="para-31">&sect;31</termref><br/>mole &ndash; amount of substance &ndash; mol: <termref ref="para-30">&sect;30</termref><br/>month &ndash; time &ndash; mo: <termref ref="para-31">&sect;31</termref><br/>month,  mean Gregorian &ndash; time &ndash; mo_g: <termref ref="para-31">&sect;31</termref><br/>month,  mean Julian &ndash; time &ndash; mo_j: <termref ref="para-31">&sect;31</termref><br/>month,  synodal &ndash; time &ndash; mo_s: <termref ref="para-31">&sect;31</termref><br/>nano &ndash; prefix  &ndash; n: <termref ref="para-27">&sect;27</termref><br/>nanovolt,  bel 10 &ndash; electric potential level &ndash; B[10.nV]: <termref ref="para-46">&sect;46</termref><br/>nautical mile &ndash; length &ndash; [nmi_br]: <termref ref="para-36">&sect;36</termref><br/>nautical mile &ndash; length &ndash; [nmi_i]: <termref ref="para-34">&sect;34</termref><br/>neper &ndash; level &ndash; Np: <termref ref="para-46">&sect;46</termref><br/>newton &ndash; force &ndash; N: <termref ref="para-30">&sect;30</termref><br/>nitrogen unit,  protein &ndash; procedure defined amount of a protein substance &ndash; [PNU]: <termref ref="para-45">&sect;45</termref><br/>number pi,  the &ndash; number &ndash; [pi]: <termref ref="para-29">&sect;29</termref><br/>number ten for arbitrary powers,  the &ndash; number &ndash; 10*: <termref ref="para-29">&sect;29</termref><br/>number ten for arbitrary powers,  the &ndash; number &ndash; 10^: <termref ref="para-29">&sect;29</termref><br/>nutrition label Calories &ndash; energy &ndash; [Cal]: <termref ref="para-43">&sect;43</termref><br/>ohm &ndash; electric resistance &ndash; Ohm: <termref ref="para-30">&sect;30</termref><br/>osmole &ndash; amount of substance (dissolved particles) &ndash; osm: <termref ref="para-45">&sect;45</termref><br/>ounce &ndash; mass &ndash; [oz_ap]: <termref ref="para-41">&sect;41</termref><br/>ounce &ndash; mass &ndash; [oz_av]: <termref ref="para-39">&sect;39</termref><br/>ounce &ndash; mass &ndash; [oz_tr]: <termref ref="para-40">&sect;40</termref><br/>ounce,  fluid &ndash; fluid volume &ndash; [foz_us]: <termref ref="para-37">&sect;37</termref><br/>ounce,  fluid &ndash; volume &ndash; [foz_br]: <termref ref="para-38">&sect;38</termref><br/>ounce,  metric fluid &ndash; fluid volume &ndash; [foz_m]: <termref ref="para-37">&sect;37</termref><br/>ounce,  metric &ndash; mass &ndash; [oz_m]: <termref ref="para-41">&sect;41</termref><br/>pH &ndash; acidity &ndash; [pH]: <termref ref="para-45">&sect;45</termref><br/>pace &ndash; length &ndash; [pc_br]: <termref ref="para-36">&sect;36</termref><br/>parsec &ndash; length &ndash; pc: <termref ref="para-31">&sect;31</termref><br/>particles total count &ndash; number &ndash; {tot}: <termref ref="para-50">&sect;50</termref><br/>parts per billion &ndash; fraction &ndash; [ppb]: <termref ref="para-29">&sect;29</termref><br/>parts per million &ndash; fraction &ndash; [ppm]: <termref ref="para-29">&sect;29</termref><br/>parts per thousand &ndash; fraction &ndash; [ppth]: <termref ref="para-29">&sect;29</termref><br/>parts per trillion &ndash; fraction &ndash; [pptr]: <termref ref="para-29">&sect;29</termref><br/>pascal &ndash; pressure &ndash; Pa: <termref ref="para-30">&sect;30</termref><br/>peck &ndash; dry volume &ndash; [pk_us]: <termref ref="para-37">&sect;37</termref><br/>peck &ndash; volume &ndash; [pk_br]: <termref ref="para-38">&sect;38</termref><br/>pennyweight &ndash; mass &ndash; [pwt_tr]: <termref ref="para-40">&sect;40</termref><br/>per billion,  parts &ndash; fraction &ndash; [ppb]: <termref ref="para-29">&sect;29</termref><br/>per heartbeat,  gram meter &ndash; proportional to ventricular stroke work &ndash; g.m/{H.B.}: <termref ref="para-50">&sect;50</termref><br/>per heartbeat,  gram-force meter &ndash; ventricular stroke work &ndash; gf.m/{H.B.}: <termref ref="para-50">&sect;50</termref><br/>per million,  parts &ndash; fraction &ndash; [ppm]: <termref ref="para-29">&sect;29</termref><br/>per square inch,  pound &ndash; pressure &ndash; [psi]: <termref ref="para-47">&sect;47</termref><br/>per square root of hertz,  meter per square seconds &ndash; amplitude spectral density &ndash; [m/s2/Hz^(1/2)]: <termref ref="para-47">&sect;47</termref><br/>per square seconds per square root of hertz,  meter &ndash; amplitude spectral density &ndash; [m/s2/Hz^(1/2)]: <termref ref="para-47">&sect;47</termref><br/>per thousand,  parts &ndash; fraction &ndash; [ppth]: <termref ref="para-29">&sect;29</termref><br/>per trillion,  parts &ndash; fraction &ndash; [pptr]: <termref ref="para-29">&sect;29</termref><br/>percent of slope &ndash; slope &ndash; %[slope]: <termref ref="para-44">&sect;44</termref><br/>percent &ndash; fraction &ndash; %: <termref ref="para-29">&sect;29</termref><br/>percent,  gram &ndash; mass concentration &ndash; g%: <termref ref="para-45">&sect;45</termref><br/>peripheral vascular resistance unit &ndash; fluid resistance &ndash; [PRU]: <termref ref="para-44">&sect;44</termref><br/>permeability of vacuum &ndash; magnetic permeability &ndash; [mu_0]: <termref ref="para-32">&sect;32</termref><br/>permittivity of vacuum &ndash; electric permittivity &ndash; [eps_0]: <termref ref="para-32">&sect;32</termref><br/>peta &ndash; prefix  &ndash; P: <termref ref="para-27">&sect;27</termref><br/>phot &ndash; illuminance &ndash; ph: <termref ref="para-33">&sect;33</termref><br/>pi,  the number &ndash; number &ndash; [pi]: <termref ref="para-29">&sect;29</termref><br/>pica &ndash; length &ndash; [pca]: <termref ref="para-42">&sect;42</termref><br/>pica,  Didot's &ndash; length &ndash; [cicero]: <termref ref="para-42">&sect;42</termref><br/>pica,  Printer's &ndash; length &ndash; [pca_pr]: <termref ref="para-42">&sect;42</termref><br/>pico &ndash; prefix  &ndash; p: <termref ref="para-27">&sect;27</termref><br/>pied &ndash; length &ndash; [pied]: <termref ref="para-42">&sect;42</termref><br/>pint &ndash; fluid volume &ndash; [pt_us]: <termref ref="para-37">&sect;37</termref><br/>pint &ndash; volume &ndash; [pt_br]: <termref ref="para-38">&sect;38</termref><br/>pint,  dry &ndash; dry volume &ndash; [dpt_us]: <termref ref="para-37">&sect;37</termref><br/>plaque forming units &ndash; amount of an infectious agent &ndash; [PFU]: <termref ref="para-45">&sect;45</termref><br/>point &ndash; length &ndash; [pnt]: <termref ref="para-42">&sect;42</termref><br/>point,  Didot's &ndash; length &ndash; [didot]: <termref ref="para-42">&sect;42</termref><br/>point,  Printer's &ndash; length &ndash; [pnt_pr]: <termref ref="para-42">&sect;42</termref><br/>potency of centesimal hahnemannian series,  homeopathic &ndash; homeopathic potency (Hahnemann) &ndash; [hp_C]: <termref ref="para-44">&sect;44</termref><br/>potency of centesimal korsakovian series,  homeopathic &ndash; homeopathic potency (Korsakov) &ndash; [kp_C]: <termref ref="para-44">&sect;44</termref><br/>potency of centesimal series (retired),  homeopathic &ndash; homeopathic potency (retired) &ndash; [hp'_C]: <termref ref="para-44">&sect;44</termref><br/>potency of decimal hahnemannian series,  homeopathic &ndash; homeopathic potency (Hahnemann) &ndash; [hp_X]: <termref ref="para-44">&sect;44</termref><br/>potency of decimal korsakovian series,  homeopathic &ndash; homeopathic potency (Korsakov) &ndash; [kp_X]: <termref ref="para-44">&sect;44</termref><br/>potency of decimal series (retired),  homeopathic &ndash; homeopathic potency (retired) &ndash; [hp'_X]: <termref ref="para-44">&sect;44</termref><br/>potency of millesimal hahnemannian series,  homeopathic &ndash; homeopathic potency (Hahnemann) &ndash; [hp_M]: <termref ref="para-44">&sect;44</termref><br/>potency of millesimal korsakovian series,  homeopathic &ndash; homeopathic potency (Korsakov) &ndash; [kp_M]: <termref ref="para-44">&sect;44</termref><br/>potency of millesimal series (retired),  homeopathic &ndash; homeopathic potency (retired) &ndash; [hp'_M]: <termref ref="para-44">&sect;44</termref><br/>potency of quintamillesimal hahnemannian series,  homeopathic &ndash; homeopathic potency (Hahnemann) &ndash; [hp_Q]: <termref ref="para-44">&sect;44</termref><br/>potency of quintamillesimal korsakovian series,  homeopathic &ndash; homeopathic potency (Korsakov) &ndash; [kp_Q]: <termref ref="para-44">&sect;44</termref><br/>potency of quintamillesimal series (retired),  homeopathic &ndash; homeopathic potency (retired) &ndash; [hp'_Q]: <termref ref="para-44">&sect;44</termref><br/>pouce &ndash; length &ndash; [pouce]: <termref ref="para-42">&sect;42</termref><br/>pound force &ndash; force &ndash; [lbf_av]: <termref ref="para-32">&sect;32</termref><br/>pound per square inch &ndash; pressure &ndash; [psi]: <termref ref="para-47">&sect;47</termref><br/>pound &ndash; mass &ndash; [lb_ap]: <termref ref="para-41">&sect;41</termref><br/>pound &ndash; mass &ndash; [lb_av]: <termref ref="para-39">&sect;39</termref><br/>pound &ndash; mass &ndash; [lb_tr]: <termref ref="para-40">&sect;40</termref><br/>power field,  high &ndash; view area in microscope &ndash; [HPF]: <termref ref="para-45">&sect;45</termref><br/>power field,  low &ndash; view area in microscope &ndash; [LPF]: <termref ref="para-45">&sect;45</termref><br/>powers,  the number ten for arbitrary &ndash; number &ndash; 10*: <termref ref="para-29">&sect;29</termref><br/>powers,  the number ten for arbitrary &ndash; number &ndash; 10^: <termref ref="para-29">&sect;29</termref><br/>pressure,  bel sound &ndash; pressure level &ndash; B[SPL]: <termref ref="para-46">&sect;46</termref><br/>prism diopter &ndash; refraction of a prism &ndash; [p'diop]: <termref ref="para-44">&sect;44</termref><br/>protein nitrogen unit &ndash; procedure defined amount of a protein substance &ndash; [PNU]: <termref ref="para-45">&sect;45</termref><br/>proton mass &ndash; mass &ndash; [m_p]: <termref ref="para-32">&sect;32</termref><br/>quart &ndash; fluid volume &ndash; [qt_us]: <termref ref="para-37">&sect;37</termref><br/>quart &ndash; volume &ndash; [qt_br]: <termref ref="para-38">&sect;38</termref><br/>quart,  dry &ndash; dry volume &ndash; [dqt_us]: <termref ref="para-37">&sect;37</termref><br/>quintamillesimal hahnemannian series,  homeopathic potency of &ndash; homeopathic potency (Hahnemann) &ndash; [hp_Q]: <termref ref="para-44">&sect;44</termref><br/>quintamillesimal korsakovian series,  homeopathic potency of &ndash; homeopathic potency (Korsakov) &ndash; [kp_Q]: <termref ref="para-44">&sect;44</termref><br/>quintamillesimal series (retired),  homeopathic potency of &ndash; homeopathic potency (retired) &ndash; [hp'_Q]: <termref ref="para-44">&sect;44</termref><br/>radian &ndash; plane angle &ndash; rad: <termref ref="para-28">&sect;28</termref><br/>radiation absorbed dose &ndash; energy dose &ndash; RAD: <termref ref="para-33">&sect;33</termref><br/>radiation equivalent man &ndash; dose equivalent &ndash; REM: <termref ref="para-33">&sect;33</termref><br/>reactivity,  index of &ndash; amount of an allergen calibrated through in-vivo testing using the Stallergenes&reg; method &ndash; [IR]: <termref ref="para-45">&sect;45</termref><br/>red blood cell count &ndash; number &ndash; {rbc}: <termref ref="para-50">&sect;50</termref><br/>resistance unit,  peripheral vascular &ndash; fluid resistance &ndash; [PRU]: <termref ref="para-44">&sect;44</termref><br/>rod &ndash; length &ndash; [rd_br]: <termref ref="para-36">&sect;36</termref><br/>rod &ndash; length &ndash; [rd_us]: <termref ref="para-35">&sect;35</termref><br/>rod,  square &ndash; area &ndash; [srd_us]: <termref ref="para-35">&sect;35</termref><br/>root of hertz,  meter per square seconds per square &ndash; amplitude spectral density &ndash; [m/s2/Hz^(1/2)]: <termref ref="para-47">&sect;47</termref><br/>scruple &ndash; mass &ndash; [sc_ap]: <termref ref="para-41">&sect;41</termref><br/>second &ndash; plane angle &ndash; '': <termref ref="para-31">&sect;31</termref><br/>second &ndash; time &ndash; s: <termref ref="para-28">&sect;28</termref><br/>seconds per square root of hertz,  meter per square &ndash; amplitude spectral density &ndash; [m/s2/Hz^(1/2)]: <termref ref="para-47">&sect;47</termref><br/>section &ndash; area &ndash; [sct]: <termref ref="para-35">&sect;35</termref><br/>series (retired),  homeopathic potency of centesimal &ndash; homeopathic potency (retired) &ndash; [hp'_C]: <termref ref="para-44">&sect;44</termref><br/>series (retired),  homeopathic potency of decimal &ndash; homeopathic potency (retired) &ndash; [hp'_X]: <termref ref="para-44">&sect;44</termref><br/>series (retired),  homeopathic potency of millesimal &ndash; homeopathic potency (retired) &ndash; [hp'_M]: <termref ref="para-44">&sect;44</termref><br/>series (retired),  homeopathic potency of quintamillesimal &ndash; homeopathic potency (retired) &ndash; [hp'_Q]: <termref ref="para-44">&sect;44</termref><br/>series,  homeopathic potency of centesimal hahnemannian &ndash; homeopathic potency (Hahnemann) &ndash; [hp_C]: <termref ref="para-44">&sect;44</termref><br/>series,  homeopathic potency of centesimal korsakovian &ndash; homeopathic potency (Korsakov) &ndash; [kp_C]: <termref ref="para-44">&sect;44</termref><br/>series,  homeopathic potency of decimal hahnemannian &ndash; homeopathic potency (Hahnemann) &ndash; [hp_X]: <termref ref="para-44">&sect;44</termref><br/>series,  homeopathic potency of decimal korsakovian &ndash; homeopathic potency (Korsakov) &ndash; [kp_X]: <termref ref="para-44">&sect;44</termref><br/>series,  homeopathic potency of millesimal hahnemannian &ndash; homeopathic potency (Hahnemann) &ndash; [hp_M]: <termref ref="para-44">&sect;44</termref><br/>series,  homeopathic potency of millesimal korsakovian &ndash; homeopathic potency (Korsakov) &ndash; [kp_M]: <termref ref="para-44">&sect;44</termref><br/>series,  homeopathic potency of quintamillesimal hahnemannian &ndash; homeopathic potency (Hahnemann) &ndash; [hp_Q]: <termref ref="para-44">&sect;44</termref><br/>series,  homeopathic potency of quintamillesimal korsakovian &ndash; homeopathic potency (Korsakov) &ndash; [kp_Q]: <termref ref="para-44">&sect;44</termref><br/>short hundredweight &ndash; mass &ndash; [scwt_av]: <termref ref="para-39">&sect;39</termref><br/>short ton &ndash; mass &ndash; [ston_av]: <termref ref="para-39">&sect;39</termref><br/>siemens &ndash; electric conductance &ndash; S: <termref ref="para-30">&sect;30</termref><br/>sievert &ndash; dose equivalent &ndash; Sv: <termref ref="para-30">&sect;30</termref><br/>slope,  percent of &ndash; slope &ndash; %[slope]: <termref ref="para-44">&sect;44</termref><br/>sound pressure,  bel &ndash; pressure level &ndash; B[SPL]: <termref ref="para-46">&sect;46</termref><br/>sphere &ndash; solid angle &ndash; sph: <termref ref="para-47">&sect;47</termref><br/>square foot &ndash; area &ndash; [sft_i]: <termref ref="para-34">&sect;34</termref><br/>square inch &ndash; area &ndash; [sin_i]: <termref ref="para-34">&sect;34</termref><br/>square inch,  pound per &ndash; pressure &ndash; [psi]: <termref ref="para-47">&sect;47</termref><br/>square mile &ndash; area &ndash; [smi_us]: <termref ref="para-35">&sect;35</termref><br/>square rod &ndash; area &ndash; [srd_us]: <termref ref="para-35">&sect;35</termref><br/>square root of hertz,  meter per square seconds per &ndash; amplitude spectral density &ndash; [m/s2/Hz^(1/2)]: <termref ref="para-47">&sect;47</termref><br/>square seconds per square root of hertz,  meter per &ndash; amplitude spectral density &ndash; [m/s2/Hz^(1/2)]: <termref ref="para-47">&sect;47</termref><br/>square yard &ndash; area &ndash; [syd_i]: <termref ref="para-34">&sect;34</termref><br/>standard acceleration of free fall &ndash; acceleration &ndash; [g]: <termref ref="para-32">&sect;32</termref><br/>standard atmosphere &ndash; pressure &ndash; atm: <termref ref="para-32">&sect;32</termref><br/>steradian &ndash; solid angle &ndash; sr: <termref ref="para-30">&sect;30</termref><br/>stere &ndash; volume &ndash; st: <termref ref="para-47">&sect;47</termref><br/>stilb &ndash; lum. intensity density &ndash; sb: <termref ref="para-33">&sect;33</termref><br/>stone &ndash; mass &ndash; [stone_av]: <termref ref="para-39">&sect;39</termref><br/>stone,  British &ndash; mass &ndash; [stone_av]: <termref ref="para-39">&sect;39</termref><br/>synodal month &ndash; time &ndash; mo_s: <termref ref="para-31">&sect;31</termref><br/>table British thermal unit,  international &ndash; energy &ndash; [Btu_IT]: <termref ref="para-43">&sect;43</termref><br/>table calorie,  international &ndash; energy &ndash; cal_IT: <termref ref="para-43">&sect;43</termref><br/>tablespoon &ndash; volume &ndash; [tbs_us]: <termref ref="para-37">&sect;37</termref><br/>tablespoon,  metric &ndash; volume &ndash; [tbs_m]: <termref ref="para-37">&sect;37</termref><br/>tablets &ndash; number &ndash; {tbl}: <termref ref="para-50">&sect;50</termref><br/>teaspoon &ndash; volume &ndash; [tsp_us]: <termref ref="para-37">&sect;37</termref><br/>teaspoon,  metric &ndash; volume &ndash; [tsp_m]: <termref ref="para-37">&sect;37</termref><br/>tebi &ndash; prefix  &ndash; Ti: <termref ref="para-49">&sect;49</termref><br/>technical atmosphere &ndash; pressure &ndash; att: <termref ref="para-47">&sect;47</termref><br/>ten for arbitrary powers,  the number &ndash; number &ndash; 10*: <termref ref="para-29">&sect;29</termref><br/>ten for arbitrary powers,  the number &ndash; number &ndash; 10^: <termref ref="para-29">&sect;29</termref><br/>tera &ndash; prefix  &ndash; T: <termref ref="para-27">&sect;27</termref><br/>tesla &ndash; magnetic flux density &ndash; T: <termref ref="para-30">&sect;30</termref><br/>tex &ndash; linear mass density (of textile thread) &ndash; tex: <termref ref="para-43">&sect;43</termref><br/>thermal unit at 39&nbsp;&deg;F,  British &ndash; energy &ndash; [Btu_39]: <termref ref="para-43">&sect;43</termref><br/>thermal unit at 59&nbsp;&deg;F,  British &ndash; energy &ndash; [Btu_59]: <termref ref="para-43">&sect;43</termref><br/>thermal unit at 60&nbsp;&deg;F,  British &ndash; energy &ndash; [Btu_60]: <termref ref="para-43">&sect;43</termref><br/>thermal unit,  British &ndash; energy &ndash; [Btu]: <termref ref="para-43">&sect;43</termref><br/>thermal unit,  international table British &ndash; energy &ndash; [Btu_IT]: <termref ref="para-43">&sect;43</termref><br/>thermal unit,  mean British &ndash; energy &ndash; [Btu_m]: <termref ref="para-43">&sect;43</termref><br/>thermal unit,  thermochemical British &ndash; energy &ndash; [Btu_th]: <termref ref="para-43">&sect;43</termref><br/>thermochemical British thermal unit &ndash; energy &ndash; [Btu_th]: <termref ref="para-43">&sect;43</termref><br/>thermochemical calorie &ndash; energy &ndash; cal_th: <termref ref="para-43">&sect;43</termref><br/>thousand,  parts per &ndash; fraction &ndash; [ppth]: <termref ref="para-29">&sect;29</termref><br/>tissue culture infectious dose,  50% &ndash; biologic activity (infectivity) of an infectious agent preparation &ndash; [TCID_50]: <termref ref="para-45">&sect;45</termref><br/>tissue,  kilogram of wet &ndash; mass &ndash; kg{wet'tis}: <termref ref="para-50">&sect;50</termref><br/>ton,  British &ndash; mass &ndash; [lton_av]: <termref ref="para-39">&sect;39</termref><br/>ton,  U.S. &ndash; mass &ndash; [ston_av]: <termref ref="para-39">&sect;39</termref><br/>ton,  long &ndash; mass &ndash; [lton_av]: <termref ref="para-39">&sect;39</termref><br/>ton,  short &ndash; mass &ndash; [ston_av]: <termref ref="para-39">&sect;39</termref><br/>tonne &ndash; mass &ndash; t: <termref ref="para-31">&sect;31</termref><br/>total count,  particles &ndash; number &ndash; {tot}: <termref ref="para-50">&sect;50</termref><br/>township &ndash; area &ndash; [twp]: <termref ref="para-35">&sect;35</termref><br/>trillion,  parts per &ndash; fraction &ndash; [pptr]: <termref ref="para-29">&sect;29</termref><br/>tropical year &ndash; time &ndash; a_t: <termref ref="para-31">&sect;31</termref><br/>tuberculin unit &ndash; biologic activity of tuberculin &ndash; [tb'U]: <termref ref="para-45">&sect;45</termref><br/>unified atomic mass unit &ndash; mass &ndash; u: <termref ref="para-31">&sect;31</termref><br/>unit at 39&nbsp;&deg;F,  British thermal &ndash; energy &ndash; [Btu_39]: <termref ref="para-43">&sect;43</termref><br/>unit at 59&nbsp;&deg;F,  British thermal &ndash; energy &ndash; [Btu_59]: <termref ref="para-43">&sect;43</termref><br/>unit at 60&nbsp;&deg;F,  British thermal &ndash; energy &ndash; [Btu_60]: <termref ref="para-43">&sect;43</termref><br/>unit for Ambrosia artemisiifolia,  allergen &ndash; procedure defined amount of the major allergen of ragweed &ndash; [Amb'a'1'U]: <termref ref="para-45">&sect;45</termref><br/>unit,  APL &ndash; biologic activity of anticardiolipin IgA &ndash; [APL'U]: <termref ref="para-45">&sect;45</termref><br/>unit,  Bethesda &ndash; biologic activity of factor VIII inhibitor &ndash; [beth'U]: <termref ref="para-45">&sect;45</termref><br/>unit,  Bodansky &ndash; biologic activity of phosphatase &ndash; [bdsk'U]: <termref ref="para-45">&sect;45</termref><br/>unit,  British thermal &ndash; energy &ndash; [Btu]: <termref ref="para-43">&sect;43</termref><br/>unit,  D-antigen &ndash; procedure defined amount of a poliomyelitis d-antigen substance &ndash; [D'ag'U]: <termref ref="para-45">&sect;45</termref><br/>unit,  Dye &ndash; biologic activity of amylase &ndash; [dye'U]: <termref ref="para-45">&sect;45</termref><br/>unit,  ELISA &ndash; arbitrary ELISA unit &ndash; [ELU]: <termref ref="para-45">&sect;45</termref><br/>unit,  Ehrlich &ndash; Ehrlich unit &ndash; [EU]: <termref ref="para-45">&sect;45</termref><br/>unit,  GPL &ndash; biologic activity of anticardiolipin IgG &ndash; [GPL'U]: <termref ref="para-45">&sect;45</termref><br/>unit,  Hounsfield &ndash; x-ray attenuation &ndash; [hnsf'U]: <termref ref="para-44">&sect;44</termref><br/>unit,  King-Armstrong &ndash; biologic activity of phosphatase &ndash; [ka'U]: <termref ref="para-45">&sect;45</termref><br/>unit,  Kunkel &ndash; arbitrary biologic activity &ndash; [knk'U]: <termref ref="para-45">&sect;45</termref><br/>unit,  MPL &ndash; biologic activity of anticardiolipin IgM &ndash; [MPL'U]: <termref ref="para-45">&sect;45</termref><br/>unit,  Mac Lagan &ndash; arbitrary biologic activity &ndash; [mclg'U]: <termref ref="para-45">&sect;45</termref><br/>unit,  Somogyi &ndash; biologic activity of amylase &ndash; [smgy'U]: <termref ref="para-45">&sect;45</termref><br/>unit,  Svedberg &ndash; sedimentation coefficient &ndash; [S]: <termref ref="para-45">&sect;45</termref><br/>unit,  Todd &ndash; biologic activity antistreptolysin O &ndash; [todd'U]: <termref ref="para-45">&sect;45</termref><br/>unit,  United States Pharmacopeia &ndash; arbitrary &ndash; [USP'U]: <termref ref="para-45">&sect;45</termref><br/>unit,  Wood &ndash; fluid resistance &ndash; [wood'U]: <termref ref="para-44">&sect;44</termref><br/>unit,  allergen &ndash; procedure defined amount of an allergen using some reference standard &ndash; [AU]: <termref ref="para-45">&sect;45</termref><br/>unit,  anti factor Xa &ndash; biologic activity of factor Xa inhibitor (heparin) &ndash; [anti'Xa'U]: <termref ref="para-45">&sect;45</termref><br/>unit,  arbitrary &ndash; arbitrary &ndash; [arb'U]: <termref ref="para-45">&sect;45</termref><br/>unit,  astronomic &ndash; length &ndash; AU: <termref ref="para-31">&sect;31</termref><br/>unit,  bioequivalent allergen &ndash; amount of an allergen calibrated through in-vivo testing based on the ID50EAL method of (intradermal dilution for 50mm sum of erythema diameters &ndash; [BAU]: <termref ref="para-45">&sect;45</termref><br/>unit,  fibrinogen equivalent &ndash; amount of fibrinogen broken down into the measured d-dimers &ndash; [FEU]: <termref ref="para-45">&sect;45</termref><br/>unit,  international table British thermal &ndash; energy &ndash; [Btu_IT]: <termref ref="para-43">&sect;43</termref><br/>unit,  international &ndash; arbitrary &ndash; [IU]: <termref ref="para-45">&sect;45</termref><br/>unit,  international &ndash; arbitrary &ndash; [iU]: <termref ref="para-45">&sect;45</termref><br/>unit,  mean British thermal &ndash; energy &ndash; [Btu_m]: <termref ref="para-43">&sect;43</termref><br/>unit,  peripheral vascular resistance &ndash; fluid resistance &ndash; [PRU]: <termref ref="para-44">&sect;44</termref><br/>unit,  protein nitrogen &ndash; procedure defined amount of a protein substance &ndash; [PNU]: <termref ref="para-45">&sect;45</termref><br/>unit,  thermochemical British thermal &ndash; energy &ndash; [Btu_th]: <termref ref="para-43">&sect;43</termref><br/>unit,  tuberculin &ndash; biologic activity of tuberculin &ndash; [tb'U]: <termref ref="para-45">&sect;45</termref><br/>unit,  unified atomic mass &ndash; mass &ndash; u: <termref ref="para-31">&sect;31</termref><br/>units,  colony forming &ndash; amount of a proliferating organism &ndash; [CFU]: <termref ref="para-45">&sect;45</termref><br/>units,  focus forming &ndash; amount of an infectious agent &ndash; [FFU]: <termref ref="para-45">&sect;45</termref><br/>units,  plaque forming &ndash; amount of an infectious agent &ndash; [PFU]: <termref ref="para-45">&sect;45</termref><br/>vacuum,  permeability of &ndash; magnetic permeability &ndash; [mu_0]: <termref ref="para-32">&sect;32</termref><br/>vacuum,  permittivity of &ndash; electric permittivity &ndash; [eps_0]: <termref ref="para-32">&sect;32</termref><br/>vascular resistance unit,  peripheral &ndash; fluid resistance &ndash; [PRU]: <termref ref="para-44">&sect;44</termref><br/>velocity of light &ndash; velocity &ndash; [c]: <termref ref="para-32">&sect;32</termref><br/>volt &ndash; electric potential &ndash; V: <termref ref="para-30">&sect;30</termref><br/>volt,  bel &ndash; electric potential level &ndash; B[V]: <termref ref="para-46">&sect;46</termref><br/>water column,  inch of &ndash; pressure &ndash; [in_i'H2O]: <termref ref="para-44">&sect;44</termref><br/>water column,  meter of &ndash; pressure &ndash; m[H2O]: <termref ref="para-44">&sect;44</termref><br/>watt &ndash; power &ndash; W: <termref ref="para-30">&sect;30</termref><br/>watt,  bel &ndash; power level &ndash; B[W]: <termref ref="para-46">&sect;46</termref><br/>weber &ndash; magnetic flux &ndash; Wb: <termref ref="para-30">&sect;30</termref><br/>week &ndash; time &ndash; wk: <termref ref="para-31">&sect;31</termref><br/>wet tissue,  kilogram of &ndash; mass &ndash; kg{wet'tis}: <termref ref="para-50">&sect;50</termref><br/>winchester gallon,  historical &ndash; dry volume &ndash; [gal_wi]: <termref ref="para-37">&sect;37</termref><br/>wine gallon,  Queen&nbsp;Anne's &ndash; fluid volume &ndash; [gal_us]: <termref ref="para-37">&sect;37</termref><br/>yard &ndash; length &ndash; [yd_br]: <termref ref="para-36">&sect;36</termref><br/>yard &ndash; length &ndash; [yd_i]: <termref ref="para-34">&sect;34</termref><br/>yard &ndash; length &ndash; [yd_us]: <termref ref="para-35">&sect;35</termref><br/>yard,  cubic &ndash; volume &ndash; [cyd_i]: <termref ref="para-34">&sect;34</termref><br/>yard,  square &ndash; area &ndash; [syd_i]: <termref ref="para-34">&sect;34</termref><br/>year &ndash; time &ndash; a: <termref ref="para-31">&sect;31</termref><br/>year,  mean Gregorian &ndash; time &ndash; a_g: <termref ref="para-31">&sect;31</termref><br/>year,  mean Julian &ndash; time &ndash; a_j: <termref ref="para-31">&sect;31</termref><br/>year,  tropical &ndash; time &ndash; a_t: <termref ref="para-31">&sect;31</termref><br/>yocto &ndash; prefix  &ndash; y: <termref ref="para-27">&sect;27</termref><br/>yotta &ndash; prefix  &ndash; Y: <termref ref="para-27">&sect;27</termref><br/>zepto &ndash; prefix  &ndash; z: <termref ref="para-27">&sect;27</termref><br/>zetta &ndash; prefix  &ndash; Z: <termref ref="para-27">&sect;27</termref><br/>&Aring;ngstr&ouml;m &ndash; length &ndash; Ao: <termref ref="para-47">&sect;47</termref><br/></td></tr></table></div2><div2><head>Alphabetic Index By Symbol</head><table class="plain" border="0" cellpadding="0" cellspacing="0"><tr valign="top"><td class="small" width="47%">% &ndash; percent &ndash; fraction: <termref ref="para-29">&sect;29</termref><br/>%[slope] &ndash; percent of slope &ndash; slope: <termref ref="para-44">&sect;44</termref><br/>' &ndash; minute &ndash; plane angle: <termref ref="para-31">&sect;31</termref><br/>'' &ndash; second &ndash; plane angle: <termref ref="para-31">&sect;31</termref><br/>10* &ndash; the number ten for arbitrary powers &ndash; number: <termref ref="para-29">&sect;29</termref><br/>10^ &ndash; the number ten for arbitrary powers &ndash; number: <termref ref="para-29">&sect;29</termref><br/>A &ndash; amp&egrave;re &ndash; electric current: <termref ref="para-30">&sect;30</termref><br/>AU &ndash; astronomic unit &ndash; length: <termref ref="para-31">&sect;31</termref><br/>Ao &ndash; &Aring;ngstr&ouml;m &ndash; length: <termref ref="para-47">&sect;47</termref><br/>B &ndash; bel &ndash; level: <termref ref="para-46">&sect;46</termref><br/>B[10.nV] &ndash; bel 10 nanovolt &ndash; electric potential level: <termref ref="para-46">&sect;46</termref><br/>B[SPL] &ndash; bel sound pressure &ndash; pressure level: <termref ref="para-46">&sect;46</termref><br/>B[V] &ndash; bel volt &ndash; electric potential level: <termref ref="para-46">&sect;46</termref><br/>B[W] &ndash; bel watt &ndash; power level: <termref ref="para-46">&sect;46</termref><br/>B[kW] &ndash; bel kilowatt &ndash; power level: <termref ref="para-46">&sect;46</termref><br/>B[mV] &ndash; bel millivolt &ndash; electric potential level: <termref ref="para-46">&sect;46</termref><br/>B[uV] &ndash; bel microvolt &ndash; electric potential level: <termref ref="para-46">&sect;46</termref><br/>Bd &ndash; baud &ndash; signal transmission rate: <termref ref="para-48">&sect;48</termref><br/>Bi &ndash; Biot &ndash; electric current: <termref ref="para-33">&sect;33</termref><br/>Bq &ndash; becquerel &ndash; radioactivity: <termref ref="para-30">&sect;30</termref><br/>By &ndash; byte &ndash; amount of information: <termref ref="para-48">&sect;48</termref><br/>C &ndash; coulomb &ndash; electric charge: <termref ref="para-28">&sect;28</termref><br/>Cel &ndash; degree Celsius &ndash; temperature: <termref ref="para-30">&sect;30</termref><br/>Ci &ndash; Curie &ndash; radioactivity: <termref ref="para-33">&sect;33</termref><br/>E &ndash; exa &ndash; prefix : <termref ref="para-27">&sect;27</termref><br/>F &ndash; farad &ndash; electric capacitance: <termref ref="para-30">&sect;30</termref><br/>G &ndash; Gauss &ndash; magnetic flux density: <termref ref="para-33">&sect;33</termref><br/>G &ndash; giga &ndash; prefix : <termref ref="para-27">&sect;27</termref><br/>Gal &ndash; Gal &ndash; acceleration: <termref ref="para-33">&sect;33</termref><br/>Gb &ndash; Gilbert &ndash; magnetic tension: <termref ref="para-33">&sect;33</termref><br/>Gi &ndash; gibi &ndash; prefix : <termref ref="para-49">&sect;49</termref><br/>Gy &ndash; gray &ndash; energy dose: <termref ref="para-30">&sect;30</termref><br/>H &ndash; henry &ndash; inductance: <termref ref="para-30">&sect;30</termref><br/>Hz &ndash; hertz &ndash; frequency: <termref ref="para-30">&sect;30</termref><br/>J &ndash; joule &ndash; energy: <termref ref="para-30">&sect;30</termref><br/>K &ndash; kelvin &ndash; temperature: <termref ref="para-28">&sect;28</termref><br/>Ki &ndash; kibi &ndash; prefix : <termref ref="para-49">&sect;49</termref><br/>Ky &ndash; Kayser &ndash; lineic number: <termref ref="para-33">&sect;33</termref><br/>L &ndash; liter &ndash; volume: <termref ref="para-31">&sect;31</termref><br/>Lmb &ndash; Lambert &ndash; brightness: <termref ref="para-33">&sect;33</termref><br/>M &ndash; mega &ndash; prefix : <termref ref="para-27">&sect;27</termref><br/>Mi &ndash; mebi &ndash; prefix : <termref ref="para-49">&sect;49</termref><br/>Mx &ndash; Maxwell &ndash; flux of magnetic induction: <termref ref="para-33">&sect;33</termref><br/>N &ndash; newton &ndash; force: <termref ref="para-30">&sect;30</termref><br/>Np &ndash; neper &ndash; level: <termref ref="para-46">&sect;46</termref><br/>Oe &ndash; Oersted &ndash; magnetic field intensity: <termref ref="para-33">&sect;33</termref><br/>Ohm &ndash; ohm &ndash; electric resistance: <termref ref="para-30">&sect;30</termref><br/>P &ndash; Poise &ndash; dynamic viscosity: <termref ref="para-33">&sect;33</termref><br/>P &ndash; peta &ndash; prefix : <termref ref="para-27">&sect;27</termref><br/>Pa &ndash; pascal &ndash; pressure: <termref ref="para-30">&sect;30</termref><br/>R &ndash; Roentgen &ndash; ion dose: <termref ref="para-33">&sect;33</termref><br/>RAD &ndash; radiation absorbed dose &ndash; energy dose: <termref ref="para-33">&sect;33</termref><br/>REM &ndash; radiation equivalent man &ndash; dose equivalent: <termref ref="para-33">&sect;33</termref><br/>S &ndash; siemens &ndash; electric conductance: <termref ref="para-30">&sect;30</termref><br/>St &ndash; Stokes &ndash; kinematic viscosity: <termref ref="para-33">&sect;33</termref><br/>Sv &ndash; sievert &ndash; dose equivalent: <termref ref="para-30">&sect;30</termref><br/>T &ndash; tera &ndash; prefix : <termref ref="para-27">&sect;27</termref><br/>T &ndash; tesla &ndash; magnetic flux density: <termref ref="para-30">&sect;30</termref><br/>Ti &ndash; tebi &ndash; prefix : <termref ref="para-49">&sect;49</termref><br/>U &ndash; Unit &ndash; catalytic activity: <termref ref="para-45">&sect;45</termref><br/>V &ndash; volt &ndash; electric potential: <termref ref="para-30">&sect;30</termref><br/>W &ndash; watt &ndash; power: <termref ref="para-30">&sect;30</termref><br/>Wb &ndash; weber &ndash; magnetic flux: <termref ref="para-30">&sect;30</termref><br/>Y &ndash; yotta &ndash; prefix : <termref ref="para-27">&sect;27</termref><br/>Z &ndash; zetta &ndash; prefix : <termref ref="para-27">&sect;27</termref><br/>[APL'U] &ndash; APL unit &ndash; biologic activity of anticardiolipin IgA: <termref ref="para-45">&sect;45</termref><br/>[AU] &ndash; allergen unit &ndash; procedure defined amount of an allergen using some reference standard: <termref ref="para-45">&sect;45</termref><br/>[Amb'a'1'U] &ndash; allergen unit for Ambrosia artemisiifolia &ndash; procedure defined amount of the major allergen of ragweed: <termref ref="para-45">&sect;45</termref><br/>[BAU] &ndash; bioequivalent allergen unit &ndash; amount of an allergen calibrated through in-vivo testing based on the ID50EAL method of (intradermal dilution for 50mm sum of erythema diameters: <termref ref="para-45">&sect;45</termref><br/>[Btu] &ndash; British thermal unit &ndash; energy: <termref ref="para-43">&sect;43</termref><br/>[Btu_39] &ndash; British thermal unit at 39&nbsp;&deg;F &ndash; energy: <termref ref="para-43">&sect;43</termref><br/>[Btu_59] &ndash; British thermal unit at 59&nbsp;&deg;F &ndash; energy: <termref ref="para-43">&sect;43</termref><br/>[Btu_60] &ndash; British thermal unit at 60&nbsp;&deg;F &ndash; energy: <termref ref="para-43">&sect;43</termref><br/>[Btu_IT] &ndash; international table British thermal unit &ndash; energy: <termref ref="para-43">&sect;43</termref><br/>[Btu_m] &ndash; mean British thermal unit &ndash; energy: <termref ref="para-43">&sect;43</termref><br/>[Btu_th] &ndash; thermochemical British thermal unit &ndash; energy: <termref ref="para-43">&sect;43</termref><br/>[CCID_50] &ndash; 50% cell culture infectious dose &ndash; biologic activity (infectivity) of an infectious agent preparation: <termref ref="para-45">&sect;45</termref><br/>[CFU] &ndash; colony forming units &ndash; amount of a proliferating organism: <termref ref="para-45">&sect;45</termref><br/>[Cal] &ndash; nutrition label Calories &ndash; energy: <termref ref="para-43">&sect;43</termref><br/>[Ch] &ndash; Charri&egrave;re french &ndash; gauge of catheters: <termref ref="para-44">&sect;44</termref><br/>[D'ag'U] &ndash; D-antigen unit &ndash; procedure defined amount of a poliomyelitis d-antigen substance: <termref ref="para-45">&sect;45</termref><br/>[EID_50] &ndash; 50% embryo infectious dose &ndash; biologic activity (infectivity) of an infectious agent preparation: <termref ref="para-45">&sect;45</termref><br/>[ELU] &ndash; ELISA unit &ndash; arbitrary ELISA unit: <termref ref="para-45">&sect;45</termref><br/>[EU] &ndash; Ehrlich unit &ndash; Ehrlich unit: <termref ref="para-45">&sect;45</termref><br/>[FEU] &ndash; fibrinogen equivalent unit &ndash; amount of fibrinogen broken down into the measured d-dimers: <termref ref="para-45">&sect;45</termref><br/>[FFU] &ndash; focus forming units &ndash; amount of an infectious agent: <termref ref="para-45">&sect;45</termref><br/>[FNU] &ndash; Formazin Nephelometric Unit &ndash; turbidity: <termref ref="para-47">&sect;47</termref><br/>[GPL'U] &ndash; GPL unit &ndash; biologic activity of anticardiolipin IgG: <termref ref="para-45">&sect;45</termref><br/>[G] &ndash; Newtonian constant of gravitation &ndash; (unclassified): <termref ref="para-32">&sect;32</termref><br/>[HPF] &ndash; high power field &ndash; view area in microscope: <termref ref="para-45">&sect;45</termref><br/>[HP] &ndash; horsepower &ndash; power: <termref ref="para-43">&sect;43</termref><br/>[IR] &ndash; index of reactivity &ndash; amount of an allergen calibrated through in-vivo testing using the Stallergenes&reg; method: <termref ref="para-45">&sect;45</termref><br/>[IU] &ndash; international unit &ndash; arbitrary: <termref ref="para-45">&sect;45</termref><br/>[LPF] &ndash; low power field &ndash; view area in microscope: <termref ref="para-45">&sect;45</termref><br/>[Lf] &ndash; Limit of flocculation &ndash; procedure defined amount of an antigen substance: <termref ref="para-45">&sect;45</termref><br/>[MET] &ndash; metabolic equivalent &ndash; metabolic cost of physical activity: <termref ref="para-44">&sect;44</termref><br/>[MPL'U] &ndash; MPL unit &ndash; biologic activity of anticardiolipin IgM: <termref ref="para-45">&sect;45</termref><br/>[NTU] &ndash; Nephelometric Turbidity Unit &ndash; turbidity: <termref ref="para-47">&sect;47</termref><br/>[PFU] &ndash; plaque forming units &ndash; amount of an infectious agent: <termref ref="para-45">&sect;45</termref><br/>[PNU] &ndash; protein nitrogen unit &ndash; procedure defined amount of a protein substance: <termref ref="para-45">&sect;45</termref><br/>[PRU] &ndash; peripheral vascular resistance unit &ndash; fluid resistance: <termref ref="para-44">&sect;44</termref><br/>[S] &ndash; Svedberg unit &ndash; sedimentation coefficient: <termref ref="para-45">&sect;45</termref><br/>[TCID_50] &ndash; 50% tissue culture infectious dose &ndash; biologic activity (infectivity) of an infectious agent preparation: <termref ref="para-45">&sect;45</termref><br/>[USP'U] &ndash; United States Pharmacopeia unit &ndash; arbitrary: <termref ref="para-45">&sect;45</termref><br/>[acr_br] &ndash; acre &ndash; area: <termref ref="para-36">&sect;36</termref><br/>[acr_us] &ndash; acre &ndash; area: <termref ref="para-35">&sect;35</termref><br/>[anti'Xa'U] &ndash; anti factor Xa unit &ndash; biologic activity of factor Xa inhibitor (heparin): <termref ref="para-45">&sect;45</termref><br/>[arb'U] &ndash; arbitrary unit &ndash; arbitrary: <termref ref="para-45">&sect;45</termref><br/>[bbl_us] &ndash; barrel &ndash; fluid volume: <termref ref="para-37">&sect;37</termref><br/>[bdsk'U] &ndash; Bodansky unit &ndash; biologic activity of phosphatase: <termref ref="para-45">&sect;45</termref><br/>[beth'U] &ndash; Bethesda unit &ndash; biologic activity of factor VIII inhibitor: <termref ref="para-45">&sect;45</termref><br/>[bf_i] &ndash; board foot &ndash; volume: <termref ref="para-34">&sect;34</termref><br/>[bu_br] &ndash; bushel &ndash; volume: <termref ref="para-38">&sect;38</termref><br/>[bu_us] &ndash; bushel &ndash; dry volume: <termref ref="para-37">&sect;37</termref><br/>[c] &ndash; velocity of light &ndash; velocity: <termref ref="para-32">&sect;32</termref><br/>[car_Au] &ndash; carat of gold alloys &ndash; mass fraction: <termref ref="para-47">&sect;47</termref><br/>[car_m] &ndash; metric carat &ndash; mass: <termref ref="para-47">&sect;47</termref><br/>[cft_i] &ndash; cubic foot &ndash; volume: <termref ref="para-34">&sect;34</termref><br/>[ch_br] &ndash; Gunter's chain &ndash; length: <termref ref="para-36">&sect;36</termref><br/>[ch_us] &ndash; Gunter's chain Surveyor's chain &ndash; length: <termref ref="para-35">&sect;35</termref><br/>[cicero] &ndash; cicero Didot's pica &ndash; length: <termref ref="para-42">&sect;42</termref><br/>[cin_i] &ndash; cubic inch &ndash; volume: <termref ref="para-34">&sect;34</termref><br/>[cml_i] &ndash; circular mil &ndash; area: <termref ref="para-34">&sect;34</termref><br/>[cr_i] &ndash; cord &ndash; volume: <termref ref="para-34">&sect;34</termref><br/>[crd_us] &ndash; cord &ndash; fluid volume: <termref ref="para-37">&sect;37</termref><br/>[cup_m] &ndash; metric cup &ndash; volume: <termref ref="para-37">&sect;37</termref><br/>[cup_us] &ndash; cup &ndash; volume: <termref ref="para-37">&sect;37</termref><br/>[cyd_i] &ndash; cubic yard &ndash; volume: <termref ref="para-34">&sect;34</termref><br/>[degF] &ndash; degree Fahrenheit &ndash; temperature: <termref ref="para-43">&sect;43</termref><br/>[degR] &ndash; degree Rankine &ndash; temperature: <termref ref="para-43">&sect;43</termref><br/>[degRe] &ndash; degree R&eacute;aumur &ndash; temperature: <termref ref="para-43">&sect;43</termref><br/>[den] &ndash; Denier &ndash; linear mass density (of textile thread): <termref ref="para-43">&sect;43</termref><br/>[didot] &ndash; didot Didot's point &ndash; length: <termref ref="para-42">&sect;42</termref><br/>[diop] &ndash; diopter &ndash; refraction of a lens: <termref ref="para-44">&sect;44</termref><br/>[dpt_us] &ndash; dry pint &ndash; dry volume: <termref ref="para-37">&sect;37</termref><br/>[dqt_us] &ndash; dry quart &ndash; dry volume: <termref ref="para-37">&sect;37</termref><br/>[dr_ap] &ndash; dram drachm &ndash; mass: <termref ref="para-41">&sect;41</termref><br/>[dr_av] &ndash; dram &ndash; mass: <termref ref="para-39">&sect;39</termref><br/>[drp] &ndash; drop &ndash; volume: <termref ref="para-44">&sect;44</termref><br/>[dye'U] &ndash; Dye unit &ndash; biologic activity of amylase: <termref ref="para-45">&sect;45</termref><br/>[e] &ndash; elementary charge &ndash; electric charge: <termref ref="para-32">&sect;32</termref><br/>[eps_0] &ndash; permittivity of vacuum &ndash; electric permittivity: <termref ref="para-32">&sect;32</termref><br/>[fdr_br] &ndash; fluid dram &ndash; volume: <termref ref="para-38">&sect;38</termref><br/>[fdr_us] &ndash; fluid dram &ndash; fluid volume: <termref ref="para-37">&sect;37</termref><br/>[foz_br] &ndash; fluid ounce &ndash; volume: <termref ref="para-38">&sect;38</termref><br/>[foz_m] &ndash; metric fluid ounce &ndash; fluid volume: <termref ref="para-37">&sect;37</termref><br/>[foz_us] &ndash; fluid ounce &ndash; fluid volume: <termref ref="para-37">&sect;37</termref><br/>[ft_br] &ndash; foot &ndash; length: <termref ref="para-36">&sect;36</termref><br/>[ft_i] &ndash; foot &ndash; length: <termref ref="para-34">&sect;34</termref><br/>[ft_us] &ndash; foot &ndash; length: <termref ref="para-35">&sect;35</termref><br/>[fth_br] &ndash; fathom &ndash; length: <termref ref="para-36">&sect;36</termref><br/>[fth_i] &ndash; fathom &ndash; depth of water: <termref ref="para-34">&sect;34</termref><br/>[fth_us] &ndash; fathom &ndash; length: <termref ref="para-35">&sect;35</termref><br/>[fur_us] &ndash; furlong &ndash; length: <termref ref="para-35">&sect;35</termref><br/>[g] &ndash; standard acceleration of free fall &ndash; acceleration: <termref ref="para-32">&sect;32</termref><br/>[gal_br] &ndash; gallon &ndash; volume: <termref ref="para-38">&sect;38</termref><br/>[gal_us] &ndash; Queen&nbsp;Anne's wine gallon &ndash; fluid volume: <termref ref="para-37">&sect;37</termref><br/>[gal_wi] &ndash; historical winchester gallon &ndash; dry volume: <termref ref="para-37">&sect;37</termref><br/>[gil_br] &ndash; gill &ndash; volume: <termref ref="para-38">&sect;38</termref><br/>[gil_us] &ndash; gill &ndash; fluid volume: <termref ref="para-37">&sect;37</termref><br/>[gr] &ndash; grain &ndash; mass: <termref ref="para-39">&sect;39</termref><br/>[h] &ndash; Planck constant &ndash; action: <termref ref="para-32">&sect;32</termref><br/>[hd_i] &ndash; hand &ndash; height of horses: <termref ref="para-34">&sect;34</termref><br/>[hnsf'U] &ndash; Hounsfield unit &ndash; x-ray attenuation: <termref ref="para-44">&sect;44</termref><br/>[hp'_C] &ndash; homeopathic potency of centesimal series (retired) &ndash; homeopathic potency (retired): <termref ref="para-44">&sect;44</termref><br/>[hp'_M] &ndash; homeopathic potency of millesimal series (retired) &ndash; homeopathic potency (retired): <termref ref="para-44">&sect;44</termref><br/>[hp'_Q] &ndash; homeopathic potency of quintamillesimal series (retired) &ndash; homeopathic potency (retired): <termref ref="para-44">&sect;44</termref><br/>[hp'_X] &ndash; homeopathic potency of decimal series (retired) &ndash; homeopathic potency (retired): <termref ref="para-44">&sect;44</termref><br/>[hp_C] &ndash; homeopathic potency of centesimal hahnemannian series &ndash; homeopathic potency (Hahnemann): <termref ref="para-44">&sect;44</termref><br/>[hp_M] &ndash; homeopathic potency of millesimal hahnemannian series &ndash; homeopathic potency (Hahnemann): <termref ref="para-44">&sect;44</termref><br/>[hp_Q] &ndash; homeopathic potency of quintamillesimal hahnemannian series &ndash; homeopathic potency (Hahnemann): <termref ref="para-44">&sect;44</termref><br/>[hp_X] &ndash; homeopathic potency of decimal hahnemannian series &ndash; homeopathic potency (Hahnemann): <termref ref="para-44">&sect;44</termref><br/></td><td class="small" width="6%">&nbsp;&nbsp;&nbsp;</td><td class="small" width="47%">[iU] &ndash; international unit &ndash; arbitrary: <termref ref="para-45">&sect;45</termref><br/>[in_br] &ndash; inch &ndash; length: <termref ref="para-36">&sect;36</termref><br/>[in_i'H2O] &ndash; inch of water column &ndash; pressure: <termref ref="para-44">&sect;44</termref><br/>[in_i'Hg] &ndash; inch of mercury column &ndash; pressure: <termref ref="para-44">&sect;44</termref><br/>[in_i] &ndash; inch &ndash; length: <termref ref="para-34">&sect;34</termref><br/>[in_us] &ndash; inch &ndash; length: <termref ref="para-35">&sect;35</termref><br/>[k] &ndash; Boltzmann constant &ndash; (unclassified): <termref ref="para-32">&sect;32</termref><br/>[ka'U] &ndash; King-Armstrong unit &ndash; biologic activity of phosphatase: <termref ref="para-45">&sect;45</termref><br/>[kn_br] &ndash; knot &ndash; velocity: <termref ref="para-36">&sect;36</termref><br/>[kn_i] &ndash; knot &ndash; velocity: <termref ref="para-34">&sect;34</termref><br/>[knk'U] &ndash; Kunkel unit &ndash; arbitrary biologic activity: <termref ref="para-45">&sect;45</termref><br/>[kp_C] &ndash; homeopathic potency of centesimal korsakovian series &ndash; homeopathic potency (Korsakov): <termref ref="para-44">&sect;44</termref><br/>[kp_M] &ndash; homeopathic potency of millesimal korsakovian series &ndash; homeopathic potency (Korsakov): <termref ref="para-44">&sect;44</termref><br/>[kp_Q] &ndash; homeopathic potency of quintamillesimal korsakovian series &ndash; homeopathic potency (Korsakov): <termref ref="para-44">&sect;44</termref><br/>[kp_X] &ndash; homeopathic potency of decimal korsakovian series &ndash; homeopathic potency (Korsakov): <termref ref="para-44">&sect;44</termref><br/>[lb_ap] &ndash; pound &ndash; mass: <termref ref="para-41">&sect;41</termref><br/>[lb_av] &ndash; pound &ndash; mass: <termref ref="para-39">&sect;39</termref><br/>[lb_tr] &ndash; pound &ndash; mass: <termref ref="para-40">&sect;40</termref><br/>[lbf_av] &ndash; pound force &ndash; force: <termref ref="para-32">&sect;32</termref><br/>[lcwt_av] &ndash; long hundredweight British hundredweight &ndash; mass: <termref ref="para-39">&sect;39</termref><br/>[ligne] &ndash; ligne French line &ndash; length: <termref ref="para-42">&sect;42</termref><br/>[lk_br] &ndash; link for Gunter's chain &ndash; length: <termref ref="para-36">&sect;36</termref><br/>[lk_us] &ndash; link for Gunter's chain &ndash; length: <termref ref="para-35">&sect;35</termref><br/>[lne] &ndash; line &ndash; length: <termref ref="para-42">&sect;42</termref><br/>[lton_av] &ndash; long ton British ton &ndash; mass: <termref ref="para-39">&sect;39</termref><br/>[ly] &ndash; light-year &ndash; length: <termref ref="para-32">&sect;32</termref><br/>[m/s2/Hz^(1/2)] &ndash; meter per square seconds per square root of hertz &ndash; amplitude spectral density: <termref ref="para-47">&sect;47</termref><br/>[m_e] &ndash; electron mass &ndash; mass: <termref ref="para-32">&sect;32</termref><br/>[m_p] &ndash; proton mass &ndash; mass: <termref ref="para-32">&sect;32</termref><br/>[mclg'U] &ndash; Mac Lagan unit &ndash; arbitrary biologic activity: <termref ref="para-45">&sect;45</termref><br/>[mesh_i] &ndash; mesh &ndash; lineic number: <termref ref="para-44">&sect;44</termref><br/>[mi_br] &ndash; mile &ndash; length: <termref ref="para-36">&sect;36</termref><br/>[mi_i] &ndash; mile &ndash; length: <termref ref="para-34">&sect;34</termref><br/>[mi_us] &ndash; mile &ndash; length: <termref ref="para-35">&sect;35</termref><br/>[mil_i] &ndash; mil &ndash; length: <termref ref="para-34">&sect;34</termref><br/>[mil_us] &ndash; mil &ndash; length: <termref ref="para-35">&sect;35</termref><br/>[min_br] &ndash; minim &ndash; volume: <termref ref="para-38">&sect;38</termref><br/>[min_us] &ndash; minim &ndash; fluid volume: <termref ref="para-37">&sect;37</termref><br/>[mu_0] &ndash; permeability of vacuum &ndash; magnetic permeability: <termref ref="para-32">&sect;32</termref><br/>[nmi_br] &ndash; nautical mile &ndash; length: <termref ref="para-36">&sect;36</termref><br/>[nmi_i] &ndash; nautical mile &ndash; length: <termref ref="para-34">&sect;34</termref><br/>[oz_ap] &ndash; ounce &ndash; mass: <termref ref="para-41">&sect;41</termref><br/>[oz_av] &ndash; ounce &ndash; mass: <termref ref="para-39">&sect;39</termref><br/>[oz_m] &ndash; metric ounce &ndash; mass: <termref ref="para-41">&sect;41</termref><br/>[oz_tr] &ndash; ounce &ndash; mass: <termref ref="para-40">&sect;40</termref><br/>[p'diop] &ndash; prism diopter &ndash; refraction of a prism: <termref ref="para-44">&sect;44</termref><br/>[pH] &ndash; pH &ndash; acidity: <termref ref="para-45">&sect;45</termref><br/>[pc_br] &ndash; pace &ndash; length: <termref ref="para-36">&sect;36</termref><br/>[pca] &ndash; pica &ndash; length: <termref ref="para-42">&sect;42</termref><br/>[pca_pr] &ndash; Printer's pica &ndash; length: <termref ref="para-42">&sect;42</termref><br/>[pi] &ndash; the number pi &ndash; number: <termref ref="para-29">&sect;29</termref><br/>[pied] &ndash; pied French foot &ndash; length: <termref ref="para-42">&sect;42</termref><br/>[pk_br] &ndash; peck &ndash; volume: <termref ref="para-38">&sect;38</termref><br/>[pk_us] &ndash; peck &ndash; dry volume: <termref ref="para-37">&sect;37</termref><br/>[pnt] &ndash; point &ndash; length: <termref ref="para-42">&sect;42</termref><br/>[pnt_pr] &ndash; Printer's point &ndash; length: <termref ref="para-42">&sect;42</termref><br/>[pouce] &ndash; pouce French inch &ndash; length: <termref ref="para-42">&sect;42</termref><br/>[ppb] &ndash; parts per billion &ndash; fraction: <termref ref="para-29">&sect;29</termref><br/>[ppm] &ndash; parts per million &ndash; fraction: <termref ref="para-29">&sect;29</termref><br/>[ppth] &ndash; parts per thousand &ndash; fraction: <termref ref="para-29">&sect;29</termref><br/>[pptr] &ndash; parts per trillion &ndash; fraction: <termref ref="para-29">&sect;29</termref><br/>[psi] &ndash; pound per square inch &ndash; pressure: <termref ref="para-47">&sect;47</termref><br/>[pt_br] &ndash; pint &ndash; volume: <termref ref="para-38">&sect;38</termref><br/>[pt_us] &ndash; pint &ndash; fluid volume: <termref ref="para-37">&sect;37</termref><br/>[pwt_tr] &ndash; pennyweight &ndash; mass: <termref ref="para-40">&sect;40</termref><br/>[qt_br] &ndash; quart &ndash; volume: <termref ref="para-38">&sect;38</termref><br/>[qt_us] &ndash; quart &ndash; fluid volume: <termref ref="para-37">&sect;37</termref><br/>[rch_us] &ndash; Ramden's chain Engineer's chain &ndash; length: <termref ref="para-35">&sect;35</termref><br/>[rd_br] &ndash; rod &ndash; length: <termref ref="para-36">&sect;36</termref><br/>[rd_us] &ndash; rod &ndash; length: <termref ref="para-35">&sect;35</termref><br/>[rlk_us] &ndash; link for Ramden's chain &ndash; length: <termref ref="para-35">&sect;35</termref><br/>[sc_ap] &ndash; scruple &ndash; mass: <termref ref="para-41">&sect;41</termref><br/>[sct] &ndash; section &ndash; area: <termref ref="para-35">&sect;35</termref><br/>[scwt_av] &ndash; short hundredweight U.S. hundredweight &ndash; mass: <termref ref="para-39">&sect;39</termref><br/>[sft_i] &ndash; square foot &ndash; area: <termref ref="para-34">&sect;34</termref><br/>[sin_i] &ndash; square inch &ndash; area: <termref ref="para-34">&sect;34</termref><br/>[smgy'U] &ndash; Somogyi unit &ndash; biologic activity of amylase: <termref ref="para-45">&sect;45</termref><br/>[smi_us] &ndash; square mile &ndash; area: <termref ref="para-35">&sect;35</termref><br/>[smoot] &ndash; Smoot &ndash; length: <termref ref="para-47">&sect;47</termref><br/>[srd_us] &ndash; square rod &ndash; area: <termref ref="para-35">&sect;35</termref><br/>[ston_av] &ndash; short ton U.S. ton &ndash; mass: <termref ref="para-39">&sect;39</termref><br/>[stone_av] &ndash; stone British stone &ndash; mass: <termref ref="para-39">&sect;39</termref><br/>[syd_i] &ndash; square yard &ndash; area: <termref ref="para-34">&sect;34</termref><br/>[tb'U] &ndash; tuberculin unit &ndash; biologic activity of tuberculin: <termref ref="para-45">&sect;45</termref><br/>[tbs_m] &ndash; metric tablespoon &ndash; volume: <termref ref="para-37">&sect;37</termref><br/>[tbs_us] &ndash; tablespoon &ndash; volume: <termref ref="para-37">&sect;37</termref><br/>[todd'U] &ndash; Todd unit &ndash; biologic activity antistreptolysin O: <termref ref="para-45">&sect;45</termref><br/>[tsp_m] &ndash; metric teaspoon &ndash; volume: <termref ref="para-37">&sect;37</termref><br/>[tsp_us] &ndash; teaspoon &ndash; volume: <termref ref="para-37">&sect;37</termref><br/>[twp] &ndash; township &ndash; area: <termref ref="para-35">&sect;35</termref><br/>[wood'U] &ndash; Wood unit &ndash; fluid resistance: <termref ref="para-44">&sect;44</termref><br/>[yd_br] &ndash; yard &ndash; length: <termref ref="para-36">&sect;36</termref><br/>[yd_i] &ndash; yard &ndash; length: <termref ref="para-34">&sect;34</termref><br/>[yd_us] &ndash; yard &ndash; length: <termref ref="para-35">&sect;35</termref><br/>a &ndash; atto &ndash; prefix : <termref ref="para-27">&sect;27</termref><br/>a &ndash; year &ndash; time: <termref ref="para-31">&sect;31</termref><br/>a_g &ndash; mean Gregorian year &ndash; time: <termref ref="para-31">&sect;31</termref><br/>a_j &ndash; mean Julian year &ndash; time: <termref ref="para-31">&sect;31</termref><br/>a_t &ndash; tropical year &ndash; time: <termref ref="para-31">&sect;31</termref><br/>ar &ndash; are &ndash; area: <termref ref="para-31">&sect;31</termref><br/>atm &ndash; standard atmosphere &ndash; pressure: <termref ref="para-32">&sect;32</termref><br/>att &ndash; technical atmosphere &ndash; pressure: <termref ref="para-47">&sect;47</termref><br/>b &ndash; barn &ndash; action area: <termref ref="para-47">&sect;47</termref><br/>bar &ndash; bar &ndash; pressure: <termref ref="para-31">&sect;31</termref><br/>bit &ndash; bit &ndash; amount of information: <termref ref="para-48">&sect;48</termref><br/>bit_s &ndash; bit &ndash; amount of information: <termref ref="para-48">&sect;48</termref><br/>c &ndash; centi &ndash; prefix : <termref ref="para-27">&sect;27</termref><br/>cal &ndash; calorie &ndash; energy: <termref ref="para-43">&sect;43</termref><br/>cal_IT &ndash; international table calorie &ndash; energy: <termref ref="para-43">&sect;43</termref><br/>cal_[15] &ndash; calorie at 15&nbsp;&deg;C &ndash; energy: <termref ref="para-43">&sect;43</termref><br/>cal_[20] &ndash; calorie at 20&nbsp;&deg;C &ndash; energy: <termref ref="para-43">&sect;43</termref><br/>cal_m &ndash; mean calorie &ndash; energy: <termref ref="para-43">&sect;43</termref><br/>cal_th &ndash; thermochemical calorie &ndash; energy: <termref ref="para-43">&sect;43</termref><br/>cd &ndash; candela &ndash; luminous intensity: <termref ref="para-28">&sect;28</termref><br/>circ &ndash; circle &ndash; plane angle: <termref ref="para-47">&sect;47</termref><br/>d &ndash; day &ndash; time: <termref ref="para-31">&sect;31</termref><br/>d &ndash; deci &ndash; prefix : <termref ref="para-27">&sect;27</termref><br/>da &ndash; deka &ndash; prefix : <termref ref="para-27">&sect;27</termref><br/>deg &ndash; degree &ndash; plane angle: <termref ref="para-31">&sect;31</termref><br/>dyn &ndash; dyne &ndash; force: <termref ref="para-33">&sect;33</termref><br/>eV &ndash; electronvolt &ndash; energy: <termref ref="para-31">&sect;31</termref><br/>eq &ndash; equivalents &ndash; amount of substance: <termref ref="para-45">&sect;45</termref><br/>erg &ndash; erg &ndash; energy: <termref ref="para-33">&sect;33</termref><br/>f &ndash; femto &ndash; prefix : <termref ref="para-27">&sect;27</termref><br/>g &ndash; gram &ndash; mass: <termref ref="para-28">&sect;28</termref><br/>g% &ndash; gram percent &ndash; mass concentration: <termref ref="para-45">&sect;45</termref><br/>g.m/{H.B.} &ndash; gram meter per heartbeat &ndash; proportional to ventricular stroke work: <termref ref="para-50">&sect;50</termref><br/>gf &ndash; gram-force &ndash; force: <termref ref="para-32">&sect;32</termref><br/>gf.m/{H.B.} &ndash; gram-force meter per heartbeat &ndash; ventricular stroke work: <termref ref="para-50">&sect;50</termref><br/>gon &ndash; gon grade &ndash; plane angle: <termref ref="para-31">&sect;31</termref><br/>h &ndash; hecto &ndash; prefix : <termref ref="para-27">&sect;27</termref><br/>h &ndash; hour &ndash; time: <termref ref="para-31">&sect;31</termref><br/>k &ndash; kilo &ndash; prefix : <termref ref="para-27">&sect;27</termref><br/>kat &ndash; katal &ndash; catalytic activity: <termref ref="para-45">&sect;45</termref><br/>kg{wet'tis} &ndash; kilogram of wet tissue &ndash; mass: <termref ref="para-50">&sect;50</termref><br/>l &ndash; liter &ndash; volume: <termref ref="para-31">&sect;31</termref><br/>lm &ndash; lumen &ndash; luminous flux: <termref ref="para-30">&sect;30</termref><br/>lx &ndash; lux &ndash; illuminance: <termref ref="para-30">&sect;30</termref><br/>m &ndash; meter &ndash; length: <termref ref="para-28">&sect;28</termref><br/>m &ndash; milli &ndash; prefix : <termref ref="para-27">&sect;27</termref><br/>m[H2O] &ndash; meter of water column &ndash; pressure: <termref ref="para-44">&sect;44</termref><br/>m[Hg] &ndash; meter of mercury column &ndash; pressure: <termref ref="para-44">&sect;44</termref><br/>mg{creat} &ndash; milligram of creatinine &ndash; mass: <termref ref="para-50">&sect;50</termref><br/>mho &ndash; mho &ndash; electric conductance: <termref ref="para-47">&sect;47</termref><br/>min &ndash; minute &ndash; time: <termref ref="para-31">&sect;31</termref><br/>mo &ndash; month &ndash; time: <termref ref="para-31">&sect;31</termref><br/>mo_g &ndash; mean Gregorian month &ndash; time: <termref ref="para-31">&sect;31</termref><br/>mo_j &ndash; mean Julian month &ndash; time: <termref ref="para-31">&sect;31</termref><br/>mo_s &ndash; synodal month &ndash; time: <termref ref="para-31">&sect;31</termref><br/>mol &ndash; mole &ndash; amount of substance: <termref ref="para-30">&sect;30</termref><br/>n &ndash; nano &ndash; prefix : <termref ref="para-27">&sect;27</termref><br/>osm &ndash; osmole &ndash; amount of substance (dissolved particles): <termref ref="para-45">&sect;45</termref><br/>p &ndash; pico &ndash; prefix : <termref ref="para-27">&sect;27</termref><br/>pc &ndash; parsec &ndash; length: <termref ref="para-31">&sect;31</termref><br/>ph &ndash; phot &ndash; illuminance: <termref ref="para-33">&sect;33</termref><br/>rad &ndash; radian &ndash; plane angle: <termref ref="para-28">&sect;28</termref><br/>s &ndash; second &ndash; time: <termref ref="para-28">&sect;28</termref><br/>sb &ndash; stilb &ndash; lum. intensity density: <termref ref="para-33">&sect;33</termref><br/>sph &ndash; sphere &ndash; solid angle: <termref ref="para-47">&sect;47</termref><br/>sr &ndash; steradian &ndash; solid angle: <termref ref="para-30">&sect;30</termref><br/>st &ndash; stere &ndash; volume: <termref ref="para-47">&sect;47</termref><br/>t &ndash; tonne &ndash; mass: <termref ref="para-31">&sect;31</termref><br/>tex &ndash; tex &ndash; linear mass density (of textile thread): <termref ref="para-43">&sect;43</termref><br/>u &ndash; micro &ndash; prefix : <termref ref="para-27">&sect;27</termref><br/>u &ndash; unified atomic mass unit &ndash; mass: <termref ref="para-31">&sect;31</termref><br/>wk &ndash; week &ndash; time: <termref ref="para-31">&sect;31</termref><br/>y &ndash; yocto &ndash; prefix : <termref ref="para-27">&sect;27</termref><br/>z &ndash; zepto &ndash; prefix : <termref ref="para-27">&sect;27</termref><br/>{rbc} &ndash; red blood cell count &ndash; number: <termref ref="para-50">&sect;50</termref><br/>{tbl} &ndash; tablets &ndash; number: <termref ref="para-50">&sect;50</termref><br/>{tot} &ndash; particles total count &ndash; number: <termref ref="para-50">&sect;50</termref><br/></td></tr></table></div2><div2><head>Alphabetic Index By Kind Of Quantity</head><table class="plain" border="0" cellpadding="0" cellspacing="0"><tr valign="top"><td class="small" width="47%">(Hahnemann),  homeopathic potency &ndash; homeopathic potency of centesimal hahnemannian series &ndash; [hp_C]: <termref ref="para-44">&sect;44</termref><br/>(Hahnemann),  homeopathic potency &ndash; homeopathic potency of decimal hahnemannian series &ndash; [hp_X]: <termref ref="para-44">&sect;44</termref><br/>(Hahnemann),  homeopathic potency &ndash; homeopathic potency of millesimal hahnemannian series &ndash; [hp_M]: <termref ref="para-44">&sect;44</termref><br/>(Hahnemann),  homeopathic potency &ndash; homeopathic potency of quintamillesimal hahnemannian series &ndash; [hp_Q]: <termref ref="para-44">&sect;44</termref><br/>(Korsakov),  homeopathic potency &ndash; homeopathic potency of centesimal korsakovian series &ndash; [kp_C]: <termref ref="para-44">&sect;44</termref><br/>(Korsakov),  homeopathic potency &ndash; homeopathic potency of decimal korsakovian series &ndash; [kp_X]: <termref ref="para-44">&sect;44</termref><br/>(Korsakov),  homeopathic potency &ndash; homeopathic potency of millesimal korsakovian series &ndash; [kp_M]: <termref ref="para-44">&sect;44</termref><br/>(Korsakov),  homeopathic potency &ndash; homeopathic potency of quintamillesimal korsakovian series &ndash; [kp_Q]: <termref ref="para-44">&sect;44</termref><br/>(dissolved particles),  amount of substance &ndash; osmole &ndash; osm: <termref ref="para-45">&sect;45</termref><br/>(heparin),  biologic activity of factor Xa inhibitor &ndash; anti factor Xa unit &ndash; [anti'Xa'U]: <termref ref="para-45">&sect;45</termref><br/>(infectivity) of an infectious agent preparation,  biologic activity &ndash; 50% cell culture infectious dose &ndash; [CCID_50]: <termref ref="para-45">&sect;45</termref><br/>(infectivity) of an infectious agent preparation,  biologic activity &ndash; 50% embryo infectious dose &ndash; [EID_50]: <termref ref="para-45">&sect;45</termref><br/>(infectivity) of an infectious agent preparation,  biologic activity &ndash; 50% tissue culture infectious dose &ndash; [TCID_50]: <termref ref="para-45">&sect;45</termref><br/>(intradermal dilution for 50mm sum of erythema diameters,  amount of an allergen calibrated through in-vivo testing based on the ID50EAL method of &ndash; bioequivalent allergen unit &ndash; [BAU]: <termref ref="para-45">&sect;45</termref><br/>(of textile thread),  linear mass density &ndash; Denier &ndash; [den]: <termref ref="para-43">&sect;43</termref><br/>(of textile thread),  linear mass density &ndash; tex &ndash; tex: <termref ref="para-43">&sect;43</termref><br/>(retired),  homeopathic potency &ndash; homeopathic potency of centesimal series (retired) &ndash; [hp'_C]: <termref ref="para-44">&sect;44</termref><br/>(retired),  homeopathic potency &ndash; homeopathic potency of decimal series (retired) &ndash; [hp'_X]: <termref ref="para-44">&sect;44</termref><br/>(retired),  homeopathic potency &ndash; homeopathic potency of millesimal series (retired) &ndash; [hp'_M]: <termref ref="para-44">&sect;44</termref><br/>(retired),  homeopathic potency &ndash; homeopathic potency of quintamillesimal series (retired) &ndash; [hp'_Q]: <termref ref="para-44">&sect;44</termref><br/>(unclassified) &ndash; Boltzmann constant &ndash; [k]: <termref ref="para-32">&sect;32</termref><br/>(unclassified) &ndash; Newtonian constant of gravitation &ndash; [G]: <termref ref="para-32">&sect;32</termref><br/>50mm sum of erythema diameters,  amount of an allergen calibrated through in-vivo testing based on the ID50EAL method of (intradermal dilution for &ndash; bioequivalent allergen unit &ndash; [BAU]: <termref ref="para-45">&sect;45</termref><br/>ELISA unit,  arbitrary &ndash; ELISA unit &ndash; [ELU]: <termref ref="para-45">&sect;45</termref><br/>Ehrlich unit &ndash; Ehrlich unit &ndash; [EU]: <termref ref="para-45">&sect;45</termref><br/>ID50EAL method of (intradermal dilution for 50mm sum of erythema diameters,  amount of an allergen calibrated through in-vivo testing based on the &ndash; bioequivalent allergen unit &ndash; [BAU]: <termref ref="para-45">&sect;45</termref><br/>IgA,  biologic activity of anticardiolipin &ndash; APL unit &ndash; [APL'U]: <termref ref="para-45">&sect;45</termref><br/>IgG,  biologic activity of anticardiolipin &ndash; GPL unit &ndash; [GPL'U]: <termref ref="para-45">&sect;45</termref><br/>IgM,  biologic activity of anticardiolipin &ndash; MPL unit &ndash; [MPL'U]: <termref ref="para-45">&sect;45</termref><br/>O,  biologic activity antistreptolysin &ndash; Todd unit &ndash; [todd'U]: <termref ref="para-45">&sect;45</termref><br/>Stallergenes&reg; method,  amount of an allergen calibrated through in-vivo testing using the &ndash; index of reactivity &ndash; [IR]: <termref ref="para-45">&sect;45</termref><br/>VIII inhibitor,  biologic activity of factor &ndash; Bethesda unit &ndash; [beth'U]: <termref ref="para-45">&sect;45</termref><br/>Xa inhibitor (heparin),  biologic activity of factor &ndash; anti factor Xa unit &ndash; [anti'Xa'U]: <termref ref="para-45">&sect;45</termref><br/>a lens,  refraction of &ndash; diopter &ndash; [diop]: <termref ref="para-44">&sect;44</termref><br/>a poliomyelitis d-antigen substance,  procedure defined amount of &ndash; D-antigen unit &ndash; [D'ag'U]: <termref ref="para-45">&sect;45</termref><br/>a prism,  refraction of &ndash; prism diopter &ndash; [p'diop]: <termref ref="para-44">&sect;44</termref><br/>a proliferating organism,  amount of &ndash; colony forming units &ndash; [CFU]: <termref ref="para-45">&sect;45</termref><br/>a protein substance,  procedure defined amount of &ndash; protein nitrogen unit &ndash; [PNU]: <termref ref="para-45">&sect;45</termref><br/>acceleration &ndash; Gal &ndash; Gal: <termref ref="para-33">&sect;33</termref><br/>acceleration &ndash; standard acceleration of free fall &ndash; [g]: <termref ref="para-32">&sect;32</termref><br/>acidity &ndash; pH &ndash; [pH]: <termref ref="para-45">&sect;45</termref><br/>action area &ndash; barn &ndash; b: <termref ref="para-47">&sect;47</termref><br/>action &ndash; Planck constant &ndash; [h]: <termref ref="para-32">&sect;32</termref><br/>activity (infectivity) of an infectious agent preparation,  biologic &ndash; 50% cell culture infectious dose &ndash; [CCID_50]: <termref ref="para-45">&sect;45</termref><br/>activity (infectivity) of an infectious agent preparation,  biologic &ndash; 50% embryo infectious dose &ndash; [EID_50]: <termref ref="para-45">&sect;45</termref><br/>activity (infectivity) of an infectious agent preparation,  biologic &ndash; 50% tissue culture infectious dose &ndash; [TCID_50]: <termref ref="para-45">&sect;45</termref><br/>activity antistreptolysin O,  biologic &ndash; Todd unit &ndash; [todd'U]: <termref ref="para-45">&sect;45</termref><br/>activity of amylase,  biologic &ndash; Dye unit &ndash; [dye'U]: <termref ref="para-45">&sect;45</termref><br/>activity of amylase,  biologic &ndash; Somogyi unit &ndash; [smgy'U]: <termref ref="para-45">&sect;45</termref><br/>activity of anticardiolipin IgA,  biologic &ndash; APL unit &ndash; [APL'U]: <termref ref="para-45">&sect;45</termref><br/>activity of anticardiolipin IgG,  biologic &ndash; GPL unit &ndash; [GPL'U]: <termref ref="para-45">&sect;45</termref><br/>activity of anticardiolipin IgM,  biologic &ndash; MPL unit &ndash; [MPL'U]: <termref ref="para-45">&sect;45</termref><br/>activity of factor VIII inhibitor,  biologic &ndash; Bethesda unit &ndash; [beth'U]: <termref ref="para-45">&sect;45</termref><br/>activity of factor Xa inhibitor (heparin),  biologic &ndash; anti factor Xa unit &ndash; [anti'Xa'U]: <termref ref="para-45">&sect;45</termref><br/>activity of phosphatase,  biologic &ndash; Bodansky unit &ndash; [bdsk'U]: <termref ref="para-45">&sect;45</termref><br/>activity of phosphatase,  biologic &ndash; King-Armstrong unit &ndash; [ka'U]: <termref ref="para-45">&sect;45</termref><br/>activity of tuberculin,  biologic &ndash; tuberculin unit &ndash; [tb'U]: <termref ref="para-45">&sect;45</termref><br/>activity,  arbitrary biologic &ndash; Kunkel unit &ndash; [knk'U]: <termref ref="para-45">&sect;45</termref><br/>activity,  arbitrary biologic &ndash; Mac Lagan unit &ndash; [mclg'U]: <termref ref="para-45">&sect;45</termref><br/>activity,  catalytic &ndash; Unit &ndash; U: <termref ref="para-45">&sect;45</termref><br/>activity,  catalytic &ndash; katal &ndash; kat: <termref ref="para-45">&sect;45</termref><br/>activity,  metabolic cost of physical &ndash; metabolic equivalent &ndash; [MET]: <termref ref="para-44">&sect;44</termref><br/>agent preparation,  biologic activity (infectivity) of an infectious &ndash; 50% cell culture infectious dose &ndash; [CCID_50]: <termref ref="para-45">&sect;45</termref><br/>agent preparation,  biologic activity (infectivity) of an infectious &ndash; 50% embryo infectious dose &ndash; [EID_50]: <termref ref="para-45">&sect;45</termref><br/>agent preparation,  biologic activity (infectivity) of an infectious &ndash; 50% tissue culture infectious dose &ndash; [TCID_50]: <termref ref="para-45">&sect;45</termref><br/>agent,  amount of an infectious &ndash; focus forming units &ndash; [FFU]: <termref ref="para-45">&sect;45</termref><br/>agent,  amount of an infectious &ndash; plaque forming units &ndash; [PFU]: <termref ref="para-45">&sect;45</termref><br/>allergen calibrated through in-vivo testing based on the ID50EAL method of (intradermal dilution for 50mm sum of erythema diameters,  amount of an &ndash; bioequivalent allergen unit &ndash; [BAU]: <termref ref="para-45">&sect;45</termref><br/>allergen calibrated through in-vivo testing using the Stallergenes&reg; method,  amount of an &ndash; index of reactivity &ndash; [IR]: <termref ref="para-45">&sect;45</termref><br/>allergen of ragweed,  procedure defined amount of the major &ndash; allergen unit for Ambrosia artemisiifolia &ndash; [Amb'a'1'U]: <termref ref="para-45">&sect;45</termref><br/>allergen using some reference standard,  procedure defined amount of an &ndash; allergen unit &ndash; [AU]: <termref ref="para-45">&sect;45</termref><br/>amount of a poliomyelitis d-antigen substance,  procedure defined &ndash; D-antigen unit &ndash; [D'ag'U]: <termref ref="para-45">&sect;45</termref><br/>amount of a proliferating organism &ndash; colony forming units &ndash; [CFU]: <termref ref="para-45">&sect;45</termref><br/>amount of a protein substance,  procedure defined &ndash; protein nitrogen unit &ndash; [PNU]: <termref ref="para-45">&sect;45</termref><br/>amount of an allergen calibrated through in-vivo testing based on the ID50EAL method of (intradermal dilution for 50mm sum of erythema diameters &ndash; bioequivalent allergen unit &ndash; [BAU]: <termref ref="para-45">&sect;45</termref><br/>amount of an allergen calibrated through in-vivo testing using the Stallergenes&reg; method &ndash; index of reactivity &ndash; [IR]: <termref ref="para-45">&sect;45</termref><br/>amount of an allergen using some reference standard,  procedure defined &ndash; allergen unit &ndash; [AU]: <termref ref="para-45">&sect;45</termref><br/>amount of an antigen substance,  procedure defined &ndash; Limit of flocculation &ndash; [Lf]: <termref ref="para-45">&sect;45</termref><br/>amount of an infectious agent &ndash; focus forming units &ndash; [FFU]: <termref ref="para-45">&sect;45</termref><br/>amount of an infectious agent &ndash; plaque forming units &ndash; [PFU]: <termref ref="para-45">&sect;45</termref><br/>amount of fibrinogen broken down into the measured d-dimers &ndash; fibrinogen equivalent unit &ndash; [FEU]: <termref ref="para-45">&sect;45</termref><br/>amount of information &ndash; bit &ndash; bit: <termref ref="para-48">&sect;48</termref><br/>amount of information &ndash; bit &ndash; bit_s: <termref ref="para-48">&sect;48</termref><br/>amount of information &ndash; byte &ndash; By: <termref ref="para-48">&sect;48</termref><br/>amount of substance (dissolved particles) &ndash; osmole &ndash; osm: <termref ref="para-45">&sect;45</termref><br/>amount of substance &ndash; equivalents &ndash; eq: <termref ref="para-45">&sect;45</termref><br/>amount of substance &ndash; mole &ndash; mol: <termref ref="para-30">&sect;30</termref><br/>amount of the major allergen of ragweed,  procedure defined &ndash; allergen unit for Ambrosia artemisiifolia &ndash; [Amb'a'1'U]: <termref ref="para-45">&sect;45</termref><br/>amplitude spectral density &ndash; meter per square seconds per square root of hertz &ndash; [m/s2/Hz^(1/2)]: <termref ref="para-47">&sect;47</termref><br/>amylase,  biologic activity of &ndash; Dye unit &ndash; [dye'U]: <termref ref="para-45">&sect;45</termref><br/>amylase,  biologic activity of &ndash; Somogyi unit &ndash; [smgy'U]: <termref ref="para-45">&sect;45</termref><br/>an allergen calibrated through in-vivo testing based on the ID50EAL method of (intradermal dilution for 50mm sum of erythema diameters,  amount of &ndash; bioequivalent allergen unit &ndash; [BAU]: <termref ref="para-45">&sect;45</termref><br/>an allergen calibrated through in-vivo testing using the Stallergenes&reg; method,  amount of &ndash; index of reactivity &ndash; [IR]: <termref ref="para-45">&sect;45</termref><br/>an allergen using some reference standard,  procedure defined amount of &ndash; allergen unit &ndash; [AU]: <termref ref="para-45">&sect;45</termref><br/>an antigen substance,  procedure defined amount of &ndash; Limit of flocculation &ndash; [Lf]: <termref ref="para-45">&sect;45</termref><br/>an infectious agent preparation,  biologic activity (infectivity) of &ndash; 50% cell culture infectious dose &ndash; [CCID_50]: <termref ref="para-45">&sect;45</termref><br/>an infectious agent preparation,  biologic activity (infectivity) of &ndash; 50% embryo infectious dose &ndash; [EID_50]: <termref ref="para-45">&sect;45</termref><br/>an infectious agent preparation,  biologic activity (infectivity) of &ndash; 50% tissue culture infectious dose &ndash; [TCID_50]: <termref ref="para-45">&sect;45</termref><br/>an infectious agent,  amount of &ndash; focus forming units &ndash; [FFU]: <termref ref="para-45">&sect;45</termref><br/>an infectious agent,  amount of &ndash; plaque forming units &ndash; [PFU]: <termref ref="para-45">&sect;45</termref><br/>angle,  plane &ndash; circle &ndash; circ: <termref ref="para-47">&sect;47</termref><br/>angle,  plane &ndash; degree &ndash; deg: <termref ref="para-31">&sect;31</termref><br/>angle,  plane &ndash; gon grade &ndash; gon: <termref ref="para-31">&sect;31</termref><br/>angle,  plane &ndash; minute &ndash; ': <termref ref="para-31">&sect;31</termref><br/>angle,  plane &ndash; radian &ndash; rad: <termref ref="para-28">&sect;28</termref><br/>angle,  plane &ndash; second &ndash; '': <termref ref="para-31">&sect;31</termref><br/>angle,  solid &ndash; sphere &ndash; sph: <termref ref="para-47">&sect;47</termref><br/>angle,  solid &ndash; steradian &ndash; sr: <termref ref="para-30">&sect;30</termref><br/>anticardiolipin IgA,  biologic activity of &ndash; APL unit &ndash; [APL'U]: <termref ref="para-45">&sect;45</termref><br/>anticardiolipin IgG,  biologic activity of &ndash; GPL unit &ndash; [GPL'U]: <termref ref="para-45">&sect;45</termref><br/>anticardiolipin IgM,  biologic activity of &ndash; MPL unit &ndash; [MPL'U]: <termref ref="para-45">&sect;45</termref><br/>antigen substance,  procedure defined amount of an &ndash; Limit of flocculation &ndash; [Lf]: <termref ref="para-45">&sect;45</termref><br/>antistreptolysin O,  biologic activity &ndash; Todd unit &ndash; [todd'U]: <termref ref="para-45">&sect;45</termref><br/>arbitrary ELISA unit &ndash; ELISA unit &ndash; [ELU]: <termref ref="para-45">&sect;45</termref><br/>arbitrary biologic activity &ndash; Kunkel unit &ndash; [knk'U]: <termref ref="para-45">&sect;45</termref><br/>arbitrary biologic activity &ndash; Mac Lagan unit &ndash; [mclg'U]: <termref ref="para-45">&sect;45</termref><br/>arbitrary &ndash; United States Pharmacopeia unit &ndash; [USP'U]: <termref ref="para-45">&sect;45</termref><br/>arbitrary &ndash; arbitrary unit &ndash; [arb'U]: <termref ref="para-45">&sect;45</termref><br/>arbitrary &ndash; international unit &ndash; [IU]: <termref ref="para-45">&sect;45</termref><br/>arbitrary &ndash; international unit &ndash; [iU]: <termref ref="para-45">&sect;45</termref><br/>area in microscope,  view &ndash; high power field &ndash; [HPF]: <termref ref="para-45">&sect;45</termref><br/>area in microscope,  view &ndash; low power field &ndash; [LPF]: <termref ref="para-45">&sect;45</termref><br/>area &ndash; acre &ndash; [acr_br]: <termref ref="para-36">&sect;36</termref><br/>area &ndash; acre &ndash; [acr_us]: <termref ref="para-35">&sect;35</termref><br/>area &ndash; are &ndash; ar: <termref ref="para-31">&sect;31</termref><br/>area &ndash; circular mil &ndash; [cml_i]: <termref ref="para-34">&sect;34</termref><br/>area &ndash; section &ndash; [sct]: <termref ref="para-35">&sect;35</termref><br/>area &ndash; square foot &ndash; [sft_i]: <termref ref="para-34">&sect;34</termref><br/>area &ndash; square inch &ndash; [sin_i]: <termref ref="para-34">&sect;34</termref><br/>area &ndash; square mile &ndash; [smi_us]: <termref ref="para-35">&sect;35</termref><br/>area &ndash; square rod &ndash; [srd_us]: <termref ref="para-35">&sect;35</termref><br/>area &ndash; square yard &ndash; [syd_i]: <termref ref="para-34">&sect;34</termref><br/>area &ndash; township &ndash; [twp]: <termref ref="para-35">&sect;35</termref><br/>area,  action &ndash; barn &ndash; b: <termref ref="para-47">&sect;47</termref><br/>attenuation,  x-ray &ndash; Hounsfield unit &ndash; [hnsf'U]: <termref ref="para-44">&sect;44</termref><br/>based on the ID50EAL method of (intradermal dilution for 50mm sum of erythema diameters,  amount of an allergen calibrated through in-vivo testing &ndash; bioequivalent allergen unit &ndash; [BAU]: <termref ref="para-45">&sect;45</termref><br/>biologic activity (infectivity) of an infectious agent preparation &ndash; 50% cell culture infectious dose &ndash; [CCID_50]: <termref ref="para-45">&sect;45</termref><br/>biologic activity (infectivity) of an infectious agent preparation &ndash; 50% embryo infectious dose &ndash; [EID_50]: <termref ref="para-45">&sect;45</termref><br/>biologic activity (infectivity) of an infectious agent preparation &ndash; 50% tissue culture infectious dose &ndash; [TCID_50]: <termref ref="para-45">&sect;45</termref><br/>biologic activity antistreptolysin O &ndash; Todd unit &ndash; [todd'U]: <termref ref="para-45">&sect;45</termref><br/>biologic activity of amylase &ndash; Dye unit &ndash; [dye'U]: <termref ref="para-45">&sect;45</termref><br/>biologic activity of amylase &ndash; Somogyi unit &ndash; [smgy'U]: <termref ref="para-45">&sect;45</termref><br/>biologic activity of anticardiolipin IgA &ndash; APL unit &ndash; [APL'U]: <termref ref="para-45">&sect;45</termref><br/>biologic activity of anticardiolipin IgG &ndash; GPL unit &ndash; [GPL'U]: <termref ref="para-45">&sect;45</termref><br/>biologic activity of anticardiolipin IgM &ndash; MPL unit &ndash; [MPL'U]: <termref ref="para-45">&sect;45</termref><br/>biologic activity of factor VIII inhibitor &ndash; Bethesda unit &ndash; [beth'U]: <termref ref="para-45">&sect;45</termref><br/>biologic activity of factor Xa inhibitor (heparin) &ndash; anti factor Xa unit &ndash; [anti'Xa'U]: <termref ref="para-45">&sect;45</termref><br/>biologic activity of phosphatase &ndash; Bodansky unit &ndash; [bdsk'U]: <termref ref="para-45">&sect;45</termref><br/>biologic activity of phosphatase &ndash; King-Armstrong unit &ndash; [ka'U]: <termref ref="para-45">&sect;45</termref><br/>biologic activity of tuberculin &ndash; tuberculin unit &ndash; [tb'U]: <termref ref="para-45">&sect;45</termref><br/>biologic activity,  arbitrary &ndash; Kunkel unit &ndash; [knk'U]: <termref ref="para-45">&sect;45</termref><br/>biologic activity,  arbitrary &ndash; Mac Lagan unit &ndash; [mclg'U]: <termref ref="para-45">&sect;45</termref><br/>brightness &ndash; Lambert &ndash; Lmb: <termref ref="para-33">&sect;33</termref><br/>broken down into the measured d-dimers,  amount of fibrinogen &ndash; fibrinogen equivalent unit &ndash; [FEU]: <termref ref="para-45">&sect;45</termref><br/>calibrated through in-vivo testing based on the ID50EAL method of (intradermal dilution for 50mm sum of erythema diameters,  amount of an allergen &ndash; bioequivalent allergen unit &ndash; [BAU]: <termref ref="para-45">&sect;45</termref><br/>calibrated through in-vivo testing using the Stallergenes&reg; method,  amount of an allergen &ndash; index of reactivity &ndash; [IR]: <termref ref="para-45">&sect;45</termref><br/>capacitance,  electric &ndash; farad &ndash; F: <termref ref="para-30">&sect;30</termref><br/>catalytic activity &ndash; Unit &ndash; U: <termref ref="para-45">&sect;45</termref><br/>catalytic activity &ndash; katal &ndash; kat: <termref ref="para-45">&sect;45</termref><br/>catheters,  gauge of &ndash; Charri&egrave;re french &ndash; [Ch]: <termref ref="para-44">&sect;44</termref><br/>charge,  electric &ndash; coulomb &ndash; C: <termref ref="para-28">&sect;28</termref><br/>charge,  electric &ndash; elementary charge &ndash; [e]: <termref ref="para-32">&sect;32</termref><br/>coefficient,  sedimentation &ndash; Svedberg unit &ndash; [S]: <termref ref="para-45">&sect;45</termref><br/>concentration,  mass &ndash; gram percent &ndash; g%: <termref ref="para-45">&sect;45</termref><br/>conductance,  electric &ndash; mho &ndash; mho: <termref ref="para-47">&sect;47</termref><br/>conductance,  electric &ndash; siemens &ndash; S: <termref ref="para-30">&sect;30</termref><br/>cost of physical activity,  metabolic &ndash; metabolic equivalent &ndash; [MET]: <termref ref="para-44">&sect;44</termref><br/>current,  electric &ndash; Biot &ndash; Bi: <termref ref="para-33">&sect;33</termref><br/>current,  electric &ndash; amp&egrave;re &ndash; A: <termref ref="para-30">&sect;30</termref><br/>d-antigen substance,  procedure defined amount of a poliomyelitis &ndash; D-antigen unit &ndash; [D'ag'U]: <termref ref="para-45">&sect;45</termref><br/>d-dimers,  amount of fibrinogen broken down into the measured &ndash; fibrinogen equivalent unit &ndash; [FEU]: <termref ref="para-45">&sect;45</termref><br/>defined amount of a poliomyelitis d-antigen substance,  procedure &ndash; D-antigen unit &ndash; [D'ag'U]: <termref ref="para-45">&sect;45</termref><br/>defined amount of a protein substance,  procedure &ndash; protein nitrogen unit &ndash; [PNU]: <termref ref="para-45">&sect;45</termref><br/>defined amount of an allergen using some reference standard,  procedure &ndash; allergen unit &ndash; [AU]: <termref ref="para-45">&sect;45</termref><br/>defined amount of an antigen substance,  procedure &ndash; Limit of flocculation &ndash; [Lf]: <termref ref="para-45">&sect;45</termref><br/>defined amount of the major allergen of ragweed,  procedure &ndash; allergen unit for Ambrosia artemisiifolia &ndash; [Amb'a'1'U]: <termref ref="para-45">&sect;45</termref><br/>density (of textile thread),  linear mass &ndash; Denier &ndash; [den]: <termref ref="para-43">&sect;43</termref><br/>density (of textile thread),  linear mass &ndash; tex &ndash; tex: <termref ref="para-43">&sect;43</termref><br/>density,  amplitude spectral &ndash; meter per square seconds per square root of hertz &ndash; [m/s2/Hz^(1/2)]: <termref ref="para-47">&sect;47</termref><br/>density,  lum. intensity &ndash; stilb &ndash; sb: <termref ref="para-33">&sect;33</termref><br/>density,  magnetic flux &ndash; Gauss &ndash; G: <termref ref="para-33">&sect;33</termref><br/>density,  magnetic flux &ndash; tesla &ndash; T: <termref ref="para-30">&sect;30</termref><br/>depth of water &ndash; fathom &ndash; [fth_i]: <termref ref="para-34">&sect;34</termref><br/>diameters,  amount of an allergen calibrated through in-vivo testing based on the ID50EAL method of (intradermal dilution for 50mm sum of erythema &ndash; bioequivalent allergen unit &ndash; [BAU]: <termref ref="para-45">&sect;45</termref><br/>dilution for 50mm sum of erythema diameters,  amount of an allergen calibrated through in-vivo testing based on the ID50EAL method of (intradermal &ndash; bioequivalent allergen unit &ndash; [BAU]: <termref ref="para-45">&sect;45</termref><br/>dose equivalent &ndash; radiation equivalent man &ndash; REM: <termref ref="para-33">&sect;33</termref><br/>dose equivalent &ndash; sievert &ndash; Sv: <termref ref="para-30">&sect;30</termref><br/>dose,  energy &ndash; gray &ndash; Gy: <termref ref="para-30">&sect;30</termref><br/>dose,  energy &ndash; radiation absorbed dose &ndash; RAD: <termref ref="para-33">&sect;33</termref><br/>dose,  ion &ndash; Roentgen &ndash; R: <termref ref="para-33">&sect;33</termref><br/>down into the measured d-dimers,  amount of fibrinogen broken &ndash; fibrinogen equivalent unit &ndash; [FEU]: <termref ref="para-45">&sect;45</termref><br/>dry volume &ndash; bushel &ndash; [bu_us]: <termref ref="para-37">&sect;37</termref><br/>dry volume &ndash; dry pint &ndash; [dpt_us]: <termref ref="para-37">&sect;37</termref><br/>dry volume &ndash; dry quart &ndash; [dqt_us]: <termref ref="para-37">&sect;37</termref><br/>dry volume &ndash; historical winchester gallon &ndash; [gal_wi]: <termref ref="para-37">&sect;37</termref><br/>dry volume &ndash; peck &ndash; [pk_us]: <termref ref="para-37">&sect;37</termref><br/>dynamic viscosity &ndash; Poise &ndash; P: <termref ref="para-33">&sect;33</termref><br/>electric capacitance &ndash; farad &ndash; F: <termref ref="para-30">&sect;30</termref><br/>electric charge &ndash; coulomb &ndash; C: <termref ref="para-28">&sect;28</termref><br/>electric charge &ndash; elementary charge &ndash; [e]: <termref ref="para-32">&sect;32</termref><br/>electric conductance &ndash; mho &ndash; mho: <termref ref="para-47">&sect;47</termref><br/>electric conductance &ndash; siemens &ndash; S: <termref ref="para-30">&sect;30</termref><br/>electric current &ndash; Biot &ndash; Bi: <termref ref="para-33">&sect;33</termref><br/>electric current &ndash; amp&egrave;re &ndash; A: <termref ref="para-30">&sect;30</termref><br/>electric permittivity &ndash; permittivity of vacuum &ndash; [eps_0]: <termref ref="para-32">&sect;32</termref><br/>electric potential level &ndash; bel 10 nanovolt &ndash; B[10.nV]: <termref ref="para-46">&sect;46</termref><br/>electric potential level &ndash; bel microvolt &ndash; B[uV]: <termref ref="para-46">&sect;46</termref><br/>electric potential level &ndash; bel millivolt &ndash; B[mV]: <termref ref="para-46">&sect;46</termref><br/>electric potential level &ndash; bel volt &ndash; B[V]: <termref ref="para-46">&sect;46</termref><br/>electric potential &ndash; volt &ndash; V: <termref ref="para-30">&sect;30</termref><br/>electric resistance &ndash; ohm &ndash; Ohm: <termref ref="para-30">&sect;30</termref><br/>energy dose &ndash; gray &ndash; Gy: <termref ref="para-30">&sect;30</termref><br/>energy dose &ndash; radiation absorbed dose &ndash; RAD: <termref ref="para-33">&sect;33</termref><br/>energy &ndash; British thermal unit at 39&nbsp;&deg;F &ndash; [Btu_39]: <termref ref="para-43">&sect;43</termref><br/>energy &ndash; British thermal unit at 59&nbsp;&deg;F &ndash; [Btu_59]: <termref ref="para-43">&sect;43</termref><br/>energy &ndash; British thermal unit at 60&nbsp;&deg;F &ndash; [Btu_60]: <termref ref="para-43">&sect;43</termref><br/>energy &ndash; British thermal unit &ndash; [Btu]: <termref ref="para-43">&sect;43</termref><br/>energy &ndash; calorie at 15&nbsp;&deg;C &ndash; cal_[15]: <termref ref="para-43">&sect;43</termref><br/>energy &ndash; calorie at 20&nbsp;&deg;C &ndash; cal_[20]: <termref ref="para-43">&sect;43</termref><br/>energy &ndash; calorie &ndash; cal: <termref ref="para-43">&sect;43</termref><br/>energy &ndash; electronvolt &ndash; eV: <termref ref="para-31">&sect;31</termref><br/>energy &ndash; erg &ndash; erg: <termref ref="para-33">&sect;33</termref><br/>energy &ndash; international table British thermal unit &ndash; [Btu_IT]: <termref ref="para-43">&sect;43</termref><br/>energy &ndash; international table calorie &ndash; cal_IT: <termref ref="para-43">&sect;43</termref><br/>energy &ndash; joule &ndash; J: <termref ref="para-30">&sect;30</termref><br/>energy &ndash; mean British thermal unit &ndash; [Btu_m]: <termref ref="para-43">&sect;43</termref><br/>energy &ndash; mean calorie &ndash; cal_m: <termref ref="para-43">&sect;43</termref><br/>energy &ndash; nutrition label Calories &ndash; [Cal]: <termref ref="para-43">&sect;43</termref><br/>energy &ndash; thermochemical British thermal unit &ndash; [Btu_th]: <termref ref="para-43">&sect;43</termref><br/>energy &ndash; thermochemical calorie &ndash; cal_th: <termref ref="para-43">&sect;43</termref><br/>equivalent,  dose &ndash; radiation equivalent man &ndash; REM: <termref ref="para-33">&sect;33</termref><br/>equivalent,  dose &ndash; sievert &ndash; Sv: <termref ref="para-30">&sect;30</termref><br/>erythema diameters,  amount of an allergen calibrated through in-vivo testing based on the ID50EAL method of (intradermal dilution for 50mm sum of &ndash; bioequivalent allergen unit &ndash; [BAU]: <termref ref="para-45">&sect;45</termref><br/>factor VIII inhibitor,  biologic activity of &ndash; Bethesda unit &ndash; [beth'U]: <termref ref="para-45">&sect;45</termref><br/>factor Xa inhibitor (heparin),  biologic activity of &ndash; anti factor Xa unit &ndash; [anti'Xa'U]: <termref ref="para-45">&sect;45</termref><br/>fibrinogen broken down into the measured d-dimers,  amount of &ndash; fibrinogen equivalent unit &ndash; [FEU]: <termref ref="para-45">&sect;45</termref><br/>field intensity,  magnetic &ndash; Oersted &ndash; Oe: <termref ref="para-33">&sect;33</termref><br/>fluid resistance &ndash; Wood unit &ndash; [wood'U]: <termref ref="para-44">&sect;44</termref><br/>fluid resistance &ndash; peripheral vascular resistance unit &ndash; [PRU]: <termref ref="para-44">&sect;44</termref><br/>fluid volume &ndash; Queen&nbsp;Anne's wine gallon &ndash; [gal_us]: <termref ref="para-37">&sect;37</termref><br/>fluid volume &ndash; barrel &ndash; [bbl_us]: <termref ref="para-37">&sect;37</termref><br/>fluid volume &ndash; cord &ndash; [crd_us]: <termref ref="para-37">&sect;37</termref><br/>fluid volume &ndash; fluid dram &ndash; [fdr_us]: <termref ref="para-37">&sect;37</termref><br/>fluid volume &ndash; fluid ounce &ndash; [foz_us]: <termref ref="para-37">&sect;37</termref><br/>fluid volume &ndash; gill &ndash; [gil_us]: <termref ref="para-37">&sect;37</termref><br/>fluid volume &ndash; metric fluid ounce &ndash; [foz_m]: <termref ref="para-37">&sect;37</termref><br/>fluid volume &ndash; minim &ndash; [min_us]: <termref ref="para-37">&sect;37</termref><br/>fluid volume &ndash; pint &ndash; [pt_us]: <termref ref="para-37">&sect;37</termref><br/>fluid volume &ndash; quart &ndash; [qt_us]: <termref ref="para-37">&sect;37</termref><br/>flux density,  magnetic &ndash; Gauss &ndash; G: <termref ref="para-33">&sect;33</termref><br/>flux density,  magnetic &ndash; tesla &ndash; T: <termref ref="para-30">&sect;30</termref><br/>flux of magnetic induction &ndash; Maxwell &ndash; Mx: <termref ref="para-33">&sect;33</termref><br/>flux,  luminous &ndash; lumen &ndash; lm: <termref ref="para-30">&sect;30</termref><br/>flux,  magnetic &ndash; weber &ndash; Wb: <termref ref="para-30">&sect;30</termref><br/>force &ndash; dyne &ndash; dyn: <termref ref="para-33">&sect;33</termref><br/>force &ndash; gram-force &ndash; gf: <termref ref="para-32">&sect;32</termref><br/>force &ndash; newton &ndash; N: <termref ref="para-30">&sect;30</termref><br/>force &ndash; pound force &ndash; [lbf_av]: <termref ref="para-32">&sect;32</termref><br/>fraction &ndash; parts per billion &ndash; [ppb]: <termref ref="para-29">&sect;29</termref><br/>fraction &ndash; parts per million &ndash; [ppm]: <termref ref="para-29">&sect;29</termref><br/>fraction &ndash; parts per thousand &ndash; [ppth]: <termref ref="para-29">&sect;29</termref><br/>fraction &ndash; parts per trillion &ndash; [pptr]: <termref ref="para-29">&sect;29</termref><br/>fraction &ndash; percent &ndash; %: <termref ref="para-29">&sect;29</termref><br/>fraction,  mass &ndash; carat of gold alloys &ndash; [car_Au]: <termref ref="para-47">&sect;47</termref><br/>frequency &ndash; hertz &ndash; Hz: <termref ref="para-30">&sect;30</termref><br/>gauge of catheters &ndash; Charri&egrave;re french &ndash; [Ch]: <termref ref="para-44">&sect;44</termref><br/>height of horses &ndash; hand &ndash; [hd_i]: <termref ref="para-34">&sect;34</termref><br/>homeopathic potency (Hahnemann) &ndash; homeopathic potency of centesimal hahnemannian series &ndash; [hp_C]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency (Hahnemann) &ndash; homeopathic potency of decimal hahnemannian series &ndash; [hp_X]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency (Hahnemann) &ndash; homeopathic potency of millesimal hahnemannian series &ndash; [hp_M]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency (Hahnemann) &ndash; homeopathic potency of quintamillesimal hahnemannian series &ndash; [hp_Q]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency (Korsakov) &ndash; homeopathic potency of centesimal korsakovian series &ndash; [kp_C]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency (Korsakov) &ndash; homeopathic potency of decimal korsakovian series &ndash; [kp_X]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency (Korsakov) &ndash; homeopathic potency of millesimal korsakovian series &ndash; [kp_M]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency (Korsakov) &ndash; homeopathic potency of quintamillesimal korsakovian series &ndash; [kp_Q]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency (retired) &ndash; homeopathic potency of centesimal series (retired) &ndash; [hp'_C]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency (retired) &ndash; homeopathic potency of decimal series (retired) &ndash; [hp'_X]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency (retired) &ndash; homeopathic potency of millesimal series (retired) &ndash; [hp'_M]: <termref ref="para-44">&sect;44</termref><br/>homeopathic potency (retired) &ndash; homeopathic potency of quintamillesimal series (retired) &ndash; [hp'_Q]: <termref ref="para-44">&sect;44</termref><br/>horses,  height of &ndash; hand &ndash; [hd_i]: <termref ref="para-34">&sect;34</termref><br/>illuminance &ndash; lux &ndash; lx: <termref ref="para-30">&sect;30</termref><br/>illuminance &ndash; phot &ndash; ph: <termref ref="para-33">&sect;33</termref><br/>in microscope,  view area &ndash; high power field &ndash; [HPF]: <termref ref="para-45">&sect;45</termref><br/>in microscope,  view area &ndash; low power field &ndash; [LPF]: <termref ref="para-45">&sect;45</termref><br/>in-vivo testing based on the ID50EAL method of (intradermal dilution for 50mm sum of erythema diameters,  amount of an allergen calibrated through &ndash; bioequivalent allergen unit &ndash; [BAU]: <termref ref="para-45">&sect;45</termref><br/>in-vivo testing using the Stallergenes&reg; method,  amount of an allergen calibrated through &ndash; index of reactivity &ndash; [IR]: <termref ref="para-45">&sect;45</termref><br/>inductance &ndash; henry &ndash; H: <termref ref="para-30">&sect;30</termref><br/>induction,  flux of magnetic &ndash; Maxwell &ndash; Mx: <termref ref="para-33">&sect;33</termref><br/>infectious agent preparation,  biologic activity (infectivity) of an &ndash; 50% cell culture infectious dose &ndash; [CCID_50]: <termref ref="para-45">&sect;45</termref><br/>infectious agent preparation,  biologic activity (infectivity) of an &ndash; 50% embryo infectious dose &ndash; [EID_50]: <termref ref="para-45">&sect;45</termref><br/>infectious agent preparation,  biologic activity (infectivity) of an &ndash; 50% tissue culture infectious dose &ndash; [TCID_50]: <termref ref="para-45">&sect;45</termref><br/>infectious agent,  amount of an &ndash; focus forming units &ndash; [FFU]: <termref ref="para-45">&sect;45</termref><br/>infectious agent,  amount of an &ndash; plaque forming units &ndash; [PFU]: <termref ref="para-45">&sect;45</termref><br/>information,  amount of &ndash; bit &ndash; bit: <termref ref="para-48">&sect;48</termref><br/></td><td class="small" width="6%">&nbsp;&nbsp;&nbsp;</td><td class="small" width="47%">information,  amount of &ndash; bit &ndash; bit_s: <termref ref="para-48">&sect;48</termref><br/>information,  amount of &ndash; byte &ndash; By: <termref ref="para-48">&sect;48</termref><br/>inhibitor (heparin),  biologic activity of factor Xa &ndash; anti factor Xa unit &ndash; [anti'Xa'U]: <termref ref="para-45">&sect;45</termref><br/>inhibitor,  biologic activity of factor VIII &ndash; Bethesda unit &ndash; [beth'U]: <termref ref="para-45">&sect;45</termref><br/>intensity density,  lum. &ndash; stilb &ndash; sb: <termref ref="para-33">&sect;33</termref><br/>intensity,  luminous &ndash; candela &ndash; cd: <termref ref="para-28">&sect;28</termref><br/>intensity,  magnetic field &ndash; Oersted &ndash; Oe: <termref ref="para-33">&sect;33</termref><br/>into the measured d-dimers,  amount of fibrinogen broken down &ndash; fibrinogen equivalent unit &ndash; [FEU]: <termref ref="para-45">&sect;45</termref><br/>ion dose &ndash; Roentgen &ndash; R: <termref ref="para-33">&sect;33</termref><br/>kinematic viscosity &ndash; Stokes &ndash; St: <termref ref="para-33">&sect;33</termref><br/>length &ndash; Gunter's chain Surveyor's chain &ndash; [ch_us]: <termref ref="para-35">&sect;35</termref><br/>length &ndash; Gunter's chain &ndash; [ch_br]: <termref ref="para-36">&sect;36</termref><br/>length &ndash; Printer's pica &ndash; [pca_pr]: <termref ref="para-42">&sect;42</termref><br/>length &ndash; Printer's point &ndash; [pnt_pr]: <termref ref="para-42">&sect;42</termref><br/>length &ndash; Ramden's chain Engineer's chain &ndash; [rch_us]: <termref ref="para-35">&sect;35</termref><br/>length &ndash; Smoot &ndash; [smoot]: <termref ref="para-47">&sect;47</termref><br/>length &ndash; astronomic unit &ndash; AU: <termref ref="para-31">&sect;31</termref><br/>length &ndash; cicero Didot's pica &ndash; [cicero]: <termref ref="para-42">&sect;42</termref><br/>length &ndash; didot Didot's point &ndash; [didot]: <termref ref="para-42">&sect;42</termref><br/>length &ndash; fathom &ndash; [fth_br]: <termref ref="para-36">&sect;36</termref><br/>length &ndash; fathom &ndash; [fth_us]: <termref ref="para-35">&sect;35</termref><br/>length &ndash; foot &ndash; [ft_br]: <termref ref="para-36">&sect;36</termref><br/>length &ndash; foot &ndash; [ft_i]: <termref ref="para-34">&sect;34</termref><br/>length &ndash; foot &ndash; [ft_us]: <termref ref="para-35">&sect;35</termref><br/>length &ndash; furlong &ndash; [fur_us]: <termref ref="para-35">&sect;35</termref><br/>length &ndash; inch &ndash; [in_br]: <termref ref="para-36">&sect;36</termref><br/>length &ndash; inch &ndash; [in_i]: <termref ref="para-34">&sect;34</termref><br/>length &ndash; inch &ndash; [in_us]: <termref ref="para-35">&sect;35</termref><br/>length &ndash; light-year &ndash; [ly]: <termref ref="para-32">&sect;32</termref><br/>length &ndash; ligne French line &ndash; [ligne]: <termref ref="para-42">&sect;42</termref><br/>length &ndash; line &ndash; [lne]: <termref ref="para-42">&sect;42</termref><br/>length &ndash; link for Gunter's chain &ndash; [lk_br]: <termref ref="para-36">&sect;36</termref><br/>length &ndash; link for Gunter's chain &ndash; [lk_us]: <termref ref="para-35">&sect;35</termref><br/>length &ndash; link for Ramden's chain &ndash; [rlk_us]: <termref ref="para-35">&sect;35</termref><br/>length &ndash; meter &ndash; m: <termref ref="para-28">&sect;28</termref><br/>length &ndash; mil &ndash; [mil_i]: <termref ref="para-34">&sect;34</termref><br/>length &ndash; mil &ndash; [mil_us]: <termref ref="para-35">&sect;35</termref><br/>length &ndash; mile &ndash; [mi_br]: <termref ref="para-36">&sect;36</termref><br/>length &ndash; mile &ndash; [mi_i]: <termref ref="para-34">&sect;34</termref><br/>length &ndash; mile &ndash; [mi_us]: <termref ref="para-35">&sect;35</termref><br/>length &ndash; nautical mile &ndash; [nmi_br]: <termref ref="para-36">&sect;36</termref><br/>length &ndash; nautical mile &ndash; [nmi_i]: <termref ref="para-34">&sect;34</termref><br/>length &ndash; pace &ndash; [pc_br]: <termref ref="para-36">&sect;36</termref><br/>length &ndash; parsec &ndash; pc: <termref ref="para-31">&sect;31</termref><br/>length &ndash; pica &ndash; [pca]: <termref ref="para-42">&sect;42</termref><br/>length &ndash; pied French foot &ndash; [pied]: <termref ref="para-42">&sect;42</termref><br/>length &ndash; point &ndash; [pnt]: <termref ref="para-42">&sect;42</termref><br/>length &ndash; pouce French inch &ndash; [pouce]: <termref ref="para-42">&sect;42</termref><br/>length &ndash; rod &ndash; [rd_br]: <termref ref="para-36">&sect;36</termref><br/>length &ndash; rod &ndash; [rd_us]: <termref ref="para-35">&sect;35</termref><br/>length &ndash; yard &ndash; [yd_br]: <termref ref="para-36">&sect;36</termref><br/>length &ndash; yard &ndash; [yd_i]: <termref ref="para-34">&sect;34</termref><br/>length &ndash; yard &ndash; [yd_us]: <termref ref="para-35">&sect;35</termref><br/>length &ndash; &Aring;ngstr&ouml;m &ndash; Ao: <termref ref="para-47">&sect;47</termref><br/>lens,  refraction of a &ndash; diopter &ndash; [diop]: <termref ref="para-44">&sect;44</termref><br/>level &ndash; bel &ndash; B: <termref ref="para-46">&sect;46</termref><br/>level &ndash; neper &ndash; Np: <termref ref="para-46">&sect;46</termref><br/>level,  electric potential &ndash; bel 10 nanovolt &ndash; B[10.nV]: <termref ref="para-46">&sect;46</termref><br/>level,  electric potential &ndash; bel microvolt &ndash; B[uV]: <termref ref="para-46">&sect;46</termref><br/>level,  electric potential &ndash; bel millivolt &ndash; B[mV]: <termref ref="para-46">&sect;46</termref><br/>level,  electric potential &ndash; bel volt &ndash; B[V]: <termref ref="para-46">&sect;46</termref><br/>level,  power &ndash; bel kilowatt &ndash; B[kW]: <termref ref="para-46">&sect;46</termref><br/>level,  power &ndash; bel watt &ndash; B[W]: <termref ref="para-46">&sect;46</termref><br/>level,  pressure &ndash; bel sound pressure &ndash; B[SPL]: <termref ref="para-46">&sect;46</termref><br/>linear mass density (of textile thread) &ndash; Denier &ndash; [den]: <termref ref="para-43">&sect;43</termref><br/>linear mass density (of textile thread) &ndash; tex &ndash; tex: <termref ref="para-43">&sect;43</termref><br/>lineic number &ndash; Kayser &ndash; Ky: <termref ref="para-33">&sect;33</termref><br/>lineic number &ndash; mesh &ndash; [mesh_i]: <termref ref="para-44">&sect;44</termref><br/>lum. intensity density &ndash; stilb &ndash; sb: <termref ref="para-33">&sect;33</termref><br/>luminous flux &ndash; lumen &ndash; lm: <termref ref="para-30">&sect;30</termref><br/>luminous intensity &ndash; candela &ndash; cd: <termref ref="para-28">&sect;28</termref><br/>magnetic field intensity &ndash; Oersted &ndash; Oe: <termref ref="para-33">&sect;33</termref><br/>magnetic flux density &ndash; Gauss &ndash; G: <termref ref="para-33">&sect;33</termref><br/>magnetic flux density &ndash; tesla &ndash; T: <termref ref="para-30">&sect;30</termref><br/>magnetic flux &ndash; weber &ndash; Wb: <termref ref="para-30">&sect;30</termref><br/>magnetic induction,  flux of &ndash; Maxwell &ndash; Mx: <termref ref="para-33">&sect;33</termref><br/>magnetic permeability &ndash; permeability of vacuum &ndash; [mu_0]: <termref ref="para-32">&sect;32</termref><br/>magnetic tension &ndash; Gilbert &ndash; Gb: <termref ref="para-33">&sect;33</termref><br/>major allergen of ragweed,  procedure defined amount of the &ndash; allergen unit for Ambrosia artemisiifolia &ndash; [Amb'a'1'U]: <termref ref="para-45">&sect;45</termref><br/>mass concentration &ndash; gram percent &ndash; g%: <termref ref="para-45">&sect;45</termref><br/>mass density (of textile thread),  linear &ndash; Denier &ndash; [den]: <termref ref="para-43">&sect;43</termref><br/>mass density (of textile thread),  linear &ndash; tex &ndash; tex: <termref ref="para-43">&sect;43</termref><br/>mass fraction &ndash; carat of gold alloys &ndash; [car_Au]: <termref ref="para-47">&sect;47</termref><br/>mass &ndash; dram drachm &ndash; [dr_ap]: <termref ref="para-41">&sect;41</termref><br/>mass &ndash; dram &ndash; [dr_av]: <termref ref="para-39">&sect;39</termref><br/>mass &ndash; electron mass &ndash; [m_e]: <termref ref="para-32">&sect;32</termref><br/>mass &ndash; grain &ndash; [gr]: <termref ref="para-39">&sect;39</termref><br/>mass &ndash; gram &ndash; g: <termref ref="para-28">&sect;28</termref><br/>mass &ndash; kilogram of wet tissue &ndash; kg{wet'tis}: <termref ref="para-50">&sect;50</termref><br/>mass &ndash; long hundredweight British hundredweight &ndash; [lcwt_av]: <termref ref="para-39">&sect;39</termref><br/>mass &ndash; long ton British ton &ndash; [lton_av]: <termref ref="para-39">&sect;39</termref><br/>mass &ndash; metric carat &ndash; [car_m]: <termref ref="para-47">&sect;47</termref><br/>mass &ndash; metric ounce &ndash; [oz_m]: <termref ref="para-41">&sect;41</termref><br/>mass &ndash; milligram of creatinine &ndash; mg{creat}: <termref ref="para-50">&sect;50</termref><br/>mass &ndash; ounce &ndash; [oz_ap]: <termref ref="para-41">&sect;41</termref><br/>mass &ndash; ounce &ndash; [oz_av]: <termref ref="para-39">&sect;39</termref><br/>mass &ndash; ounce &ndash; [oz_tr]: <termref ref="para-40">&sect;40</termref><br/>mass &ndash; pennyweight &ndash; [pwt_tr]: <termref ref="para-40">&sect;40</termref><br/>mass &ndash; pound &ndash; [lb_ap]: <termref ref="para-41">&sect;41</termref><br/>mass &ndash; pound &ndash; [lb_av]: <termref ref="para-39">&sect;39</termref><br/>mass &ndash; pound &ndash; [lb_tr]: <termref ref="para-40">&sect;40</termref><br/>mass &ndash; proton mass &ndash; [m_p]: <termref ref="para-32">&sect;32</termref><br/>mass &ndash; scruple &ndash; [sc_ap]: <termref ref="para-41">&sect;41</termref><br/>mass &ndash; short hundredweight U.S. hundredweight &ndash; [scwt_av]: <termref ref="para-39">&sect;39</termref><br/>mass &ndash; short ton U.S. ton &ndash; [ston_av]: <termref ref="para-39">&sect;39</termref><br/>mass &ndash; stone British stone &ndash; [stone_av]: <termref ref="para-39">&sect;39</termref><br/>mass &ndash; tonne &ndash; t: <termref ref="para-31">&sect;31</termref><br/>mass &ndash; unified atomic mass unit &ndash; u: <termref ref="para-31">&sect;31</termref><br/>measured d-dimers,  amount of fibrinogen broken down into the &ndash; fibrinogen equivalent unit &ndash; [FEU]: <termref ref="para-45">&sect;45</termref><br/>metabolic cost of physical activity &ndash; metabolic equivalent &ndash; [MET]: <termref ref="para-44">&sect;44</termref><br/>method of (intradermal dilution for 50mm sum of erythema diameters,  amount of an allergen calibrated through in-vivo testing based on the ID50EAL &ndash; bioequivalent allergen unit &ndash; [BAU]: <termref ref="para-45">&sect;45</termref><br/>method,  amount of an allergen calibrated through in-vivo testing using the Stallergenes&reg; &ndash; index of reactivity &ndash; [IR]: <termref ref="para-45">&sect;45</termref><br/>microscope,  view area in &ndash; high power field &ndash; [HPF]: <termref ref="para-45">&sect;45</termref><br/>microscope,  view area in &ndash; low power field &ndash; [LPF]: <termref ref="para-45">&sect;45</termref><br/>number &ndash; particles total count &ndash; {tot}: <termref ref="para-50">&sect;50</termref><br/>number &ndash; red blood cell count &ndash; {rbc}: <termref ref="para-50">&sect;50</termref><br/>number &ndash; tablets &ndash; {tbl}: <termref ref="para-50">&sect;50</termref><br/>number &ndash; the number pi &ndash; [pi]: <termref ref="para-29">&sect;29</termref><br/>number &ndash; the number ten for arbitrary powers &ndash; 10*: <termref ref="para-29">&sect;29</termref><br/>number &ndash; the number ten for arbitrary powers &ndash; 10^: <termref ref="para-29">&sect;29</termref><br/>number,  lineic &ndash; Kayser &ndash; Ky: <termref ref="para-33">&sect;33</termref><br/>number,  lineic &ndash; mesh &ndash; [mesh_i]: <termref ref="para-44">&sect;44</termref><br/>on the ID50EAL method of (intradermal dilution for 50mm sum of erythema diameters,  amount of an allergen calibrated through in-vivo testing based &ndash; bioequivalent allergen unit &ndash; [BAU]: <termref ref="para-45">&sect;45</termref><br/>organism,  amount of a proliferating &ndash; colony forming units &ndash; [CFU]: <termref ref="para-45">&sect;45</termref><br/>particles),  amount of substance (dissolved &ndash; osmole &ndash; osm: <termref ref="para-45">&sect;45</termref><br/>permeability,  magnetic &ndash; permeability of vacuum &ndash; [mu_0]: <termref ref="para-32">&sect;32</termref><br/>permittivity,  electric &ndash; permittivity of vacuum &ndash; [eps_0]: <termref ref="para-32">&sect;32</termref><br/>phosphatase,  biologic activity of &ndash; Bodansky unit &ndash; [bdsk'U]: <termref ref="para-45">&sect;45</termref><br/>phosphatase,  biologic activity of &ndash; King-Armstrong unit &ndash; [ka'U]: <termref ref="para-45">&sect;45</termref><br/>physical activity,  metabolic cost of &ndash; metabolic equivalent &ndash; [MET]: <termref ref="para-44">&sect;44</termref><br/>plane angle &ndash; circle &ndash; circ: <termref ref="para-47">&sect;47</termref><br/>plane angle &ndash; degree &ndash; deg: <termref ref="para-31">&sect;31</termref><br/>plane angle &ndash; gon grade &ndash; gon: <termref ref="para-31">&sect;31</termref><br/>plane angle &ndash; minute &ndash; ': <termref ref="para-31">&sect;31</termref><br/>plane angle &ndash; radian &ndash; rad: <termref ref="para-28">&sect;28</termref><br/>plane angle &ndash; second &ndash; '': <termref ref="para-31">&sect;31</termref><br/>poliomyelitis d-antigen substance,  procedure defined amount of a &ndash; D-antigen unit &ndash; [D'ag'U]: <termref ref="para-45">&sect;45</termref><br/>potency (Hahnemann),  homeopathic &ndash; homeopathic potency of centesimal hahnemannian series &ndash; [hp_C]: <termref ref="para-44">&sect;44</termref><br/>potency (Hahnemann),  homeopathic &ndash; homeopathic potency of decimal hahnemannian series &ndash; [hp_X]: <termref ref="para-44">&sect;44</termref><br/>potency (Hahnemann),  homeopathic &ndash; homeopathic potency of millesimal hahnemannian series &ndash; [hp_M]: <termref ref="para-44">&sect;44</termref><br/>potency (Hahnemann),  homeopathic &ndash; homeopathic potency of quintamillesimal hahnemannian series &ndash; [hp_Q]: <termref ref="para-44">&sect;44</termref><br/>potency (Korsakov),  homeopathic &ndash; homeopathic potency of centesimal korsakovian series &ndash; [kp_C]: <termref ref="para-44">&sect;44</termref><br/>potency (Korsakov),  homeopathic &ndash; homeopathic potency of decimal korsakovian series &ndash; [kp_X]: <termref ref="para-44">&sect;44</termref><br/>potency (Korsakov),  homeopathic &ndash; homeopathic potency of millesimal korsakovian series &ndash; [kp_M]: <termref ref="para-44">&sect;44</termref><br/>potency (Korsakov),  homeopathic &ndash; homeopathic potency of quintamillesimal korsakovian series &ndash; [kp_Q]: <termref ref="para-44">&sect;44</termref><br/>potency (retired),  homeopathic &ndash; homeopathic potency of centesimal series (retired) &ndash; [hp'_C]: <termref ref="para-44">&sect;44</termref><br/>potency (retired),  homeopathic &ndash; homeopathic potency of decimal series (retired) &ndash; [hp'_X]: <termref ref="para-44">&sect;44</termref><br/>potency (retired),  homeopathic &ndash; homeopathic potency of millesimal series (retired) &ndash; [hp'_M]: <termref ref="para-44">&sect;44</termref><br/>potency (retired),  homeopathic &ndash; homeopathic potency of quintamillesimal series (retired) &ndash; [hp'_Q]: <termref ref="para-44">&sect;44</termref><br/>potential level,  electric &ndash; bel 10 nanovolt &ndash; B[10.nV]: <termref ref="para-46">&sect;46</termref><br/>potential level,  electric &ndash; bel microvolt &ndash; B[uV]: <termref ref="para-46">&sect;46</termref><br/>potential level,  electric &ndash; bel millivolt &ndash; B[mV]: <termref ref="para-46">&sect;46</termref><br/>potential level,  electric &ndash; bel volt &ndash; B[V]: <termref ref="para-46">&sect;46</termref><br/>potential,  electric &ndash; volt &ndash; V: <termref ref="para-30">&sect;30</termref><br/>power level &ndash; bel kilowatt &ndash; B[kW]: <termref ref="para-46">&sect;46</termref><br/>power level &ndash; bel watt &ndash; B[W]: <termref ref="para-46">&sect;46</termref><br/>power &ndash; horsepower &ndash; [HP]: <termref ref="para-43">&sect;43</termref><br/>power &ndash; watt &ndash; W: <termref ref="para-30">&sect;30</termref><br/>preparation,  biologic activity (infectivity) of an infectious agent &ndash; 50% cell culture infectious dose &ndash; [CCID_50]: <termref ref="para-45">&sect;45</termref><br/>preparation,  biologic activity (infectivity) of an infectious agent &ndash; 50% embryo infectious dose &ndash; [EID_50]: <termref ref="para-45">&sect;45</termref><br/>preparation,  biologic activity (infectivity) of an infectious agent &ndash; 50% tissue culture infectious dose &ndash; [TCID_50]: <termref ref="para-45">&sect;45</termref><br/>pressure level &ndash; bel sound pressure &ndash; B[SPL]: <termref ref="para-46">&sect;46</termref><br/>pressure &ndash; bar &ndash; bar: <termref ref="para-31">&sect;31</termref><br/>pressure &ndash; inch of mercury column &ndash; [in_i'Hg]: <termref ref="para-44">&sect;44</termref><br/>pressure &ndash; inch of water column &ndash; [in_i'H2O]: <termref ref="para-44">&sect;44</termref><br/>pressure &ndash; meter of mercury column &ndash; m[Hg]: <termref ref="para-44">&sect;44</termref><br/>pressure &ndash; meter of water column &ndash; m[H2O]: <termref ref="para-44">&sect;44</termref><br/>pressure &ndash; pascal &ndash; Pa: <termref ref="para-30">&sect;30</termref><br/>pressure &ndash; pound per square inch &ndash; [psi]: <termref ref="para-47">&sect;47</termref><br/>pressure &ndash; standard atmosphere &ndash; atm: <termref ref="para-32">&sect;32</termref><br/>pressure &ndash; technical atmosphere &ndash; att: <termref ref="para-47">&sect;47</termref><br/>prism,  refraction of a &ndash; prism diopter &ndash; [p'diop]: <termref ref="para-44">&sect;44</termref><br/>procedure defined amount of a poliomyelitis d-antigen substance &ndash; D-antigen unit &ndash; [D'ag'U]: <termref ref="para-45">&sect;45</termref><br/>procedure defined amount of a protein substance &ndash; protein nitrogen unit &ndash; [PNU]: <termref ref="para-45">&sect;45</termref><br/>procedure defined amount of an allergen using some reference standard &ndash; allergen unit &ndash; [AU]: <termref ref="para-45">&sect;45</termref><br/>procedure defined amount of an antigen substance &ndash; Limit of flocculation &ndash; [Lf]: <termref ref="para-45">&sect;45</termref><br/>procedure defined amount of the major allergen of ragweed &ndash; allergen unit for Ambrosia artemisiifolia &ndash; [Amb'a'1'U]: <termref ref="para-45">&sect;45</termref><br/>proliferating organism,  amount of a &ndash; colony forming units &ndash; [CFU]: <termref ref="para-45">&sect;45</termref><br/>proportional to ventricular stroke work &ndash; gram meter per heartbeat &ndash; g.m/{H.B.}: <termref ref="para-50">&sect;50</termref><br/>protein substance,  procedure defined amount of a &ndash; protein nitrogen unit &ndash; [PNU]: <termref ref="para-45">&sect;45</termref><br/>radioactivity &ndash; Curie &ndash; Ci: <termref ref="para-33">&sect;33</termref><br/>radioactivity &ndash; becquerel &ndash; Bq: <termref ref="para-30">&sect;30</termref><br/>ragweed,  procedure defined amount of the major allergen of &ndash; allergen unit for Ambrosia artemisiifolia &ndash; [Amb'a'1'U]: <termref ref="para-45">&sect;45</termref><br/>rate,  signal transmission &ndash; baud &ndash; Bd: <termref ref="para-48">&sect;48</termref><br/>reference standard,  procedure defined amount of an allergen using some &ndash; allergen unit &ndash; [AU]: <termref ref="para-45">&sect;45</termref><br/>refraction of a lens &ndash; diopter &ndash; [diop]: <termref ref="para-44">&sect;44</termref><br/>refraction of a prism &ndash; prism diopter &ndash; [p'diop]: <termref ref="para-44">&sect;44</termref><br/>resistance,  electric &ndash; ohm &ndash; Ohm: <termref ref="para-30">&sect;30</termref><br/>resistance,  fluid &ndash; Wood unit &ndash; [wood'U]: <termref ref="para-44">&sect;44</termref><br/>resistance,  fluid &ndash; peripheral vascular resistance unit &ndash; [PRU]: <termref ref="para-44">&sect;44</termref><br/>sedimentation coefficient &ndash; Svedberg unit &ndash; [S]: <termref ref="para-45">&sect;45</termref><br/>signal transmission rate &ndash; baud &ndash; Bd: <termref ref="para-48">&sect;48</termref><br/>slope &ndash; percent of slope &ndash; %[slope]: <termref ref="para-44">&sect;44</termref><br/>solid angle &ndash; sphere &ndash; sph: <termref ref="para-47">&sect;47</termref><br/>solid angle &ndash; steradian &ndash; sr: <termref ref="para-30">&sect;30</termref><br/>some reference standard,  procedure defined amount of an allergen using &ndash; allergen unit &ndash; [AU]: <termref ref="para-45">&sect;45</termref><br/>spectral density,  amplitude &ndash; meter per square seconds per square root of hertz &ndash; [m/s2/Hz^(1/2)]: <termref ref="para-47">&sect;47</termref><br/>standard,  procedure defined amount of an allergen using some reference &ndash; allergen unit &ndash; [AU]: <termref ref="para-45">&sect;45</termref><br/>stroke work,  proportional to ventricular &ndash; gram meter per heartbeat &ndash; g.m/{H.B.}: <termref ref="para-50">&sect;50</termref><br/>stroke work,  ventricular &ndash; gram-force meter per heartbeat &ndash; gf.m/{H.B.}: <termref ref="para-50">&sect;50</termref><br/>substance (dissolved particles),  amount of &ndash; osmole &ndash; osm: <termref ref="para-45">&sect;45</termref><br/>substance,  amount of &ndash; equivalents &ndash; eq: <termref ref="para-45">&sect;45</termref><br/>substance,  amount of &ndash; mole &ndash; mol: <termref ref="para-30">&sect;30</termref><br/>substance,  procedure defined amount of a poliomyelitis d-antigen &ndash; D-antigen unit &ndash; [D'ag'U]: <termref ref="para-45">&sect;45</termref><br/>substance,  procedure defined amount of a protein &ndash; protein nitrogen unit &ndash; [PNU]: <termref ref="para-45">&sect;45</termref><br/>substance,  procedure defined amount of an antigen &ndash; Limit of flocculation &ndash; [Lf]: <termref ref="para-45">&sect;45</termref><br/>sum of erythema diameters,  amount of an allergen calibrated through in-vivo testing based on the ID50EAL method of (intradermal dilution for 50mm &ndash; bioequivalent allergen unit &ndash; [BAU]: <termref ref="para-45">&sect;45</termref><br/>temperature &ndash; degree Celsius &ndash; Cel: <termref ref="para-30">&sect;30</termref><br/>temperature &ndash; degree Fahrenheit &ndash; [degF]: <termref ref="para-43">&sect;43</termref><br/>temperature &ndash; degree Rankine &ndash; [degR]: <termref ref="para-43">&sect;43</termref><br/>temperature &ndash; degree R&eacute;aumur &ndash; [degRe]: <termref ref="para-43">&sect;43</termref><br/>temperature &ndash; kelvin &ndash; K: <termref ref="para-28">&sect;28</termref><br/>tension,  magnetic &ndash; Gilbert &ndash; Gb: <termref ref="para-33">&sect;33</termref><br/>testing based on the ID50EAL method of (intradermal dilution for 50mm sum of erythema diameters,  amount of an allergen calibrated through in-vivo &ndash; bioequivalent allergen unit &ndash; [BAU]: <termref ref="para-45">&sect;45</termref><br/>testing using the Stallergenes&reg; method,  amount of an allergen calibrated through in-vivo &ndash; index of reactivity &ndash; [IR]: <termref ref="para-45">&sect;45</termref><br/>textile thread),  linear mass density (of &ndash; Denier &ndash; [den]: <termref ref="para-43">&sect;43</termref><br/>textile thread),  linear mass density (of &ndash; tex &ndash; tex: <termref ref="para-43">&sect;43</termref><br/>thread),  linear mass density (of textile &ndash; Denier &ndash; [den]: <termref ref="para-43">&sect;43</termref><br/>thread),  linear mass density (of textile &ndash; tex &ndash; tex: <termref ref="para-43">&sect;43</termref><br/>through in-vivo testing based on the ID50EAL method of (intradermal dilution for 50mm sum of erythema diameters,  amount of an allergen calibrated &ndash; bioequivalent allergen unit &ndash; [BAU]: <termref ref="para-45">&sect;45</termref><br/>through in-vivo testing using the Stallergenes&reg; method,  amount of an allergen calibrated &ndash; index of reactivity &ndash; [IR]: <termref ref="para-45">&sect;45</termref><br/>time &ndash; day &ndash; d: <termref ref="para-31">&sect;31</termref><br/>time &ndash; hour &ndash; h: <termref ref="para-31">&sect;31</termref><br/>time &ndash; mean Gregorian month &ndash; mo_g: <termref ref="para-31">&sect;31</termref><br/>time &ndash; mean Gregorian year &ndash; a_g: <termref ref="para-31">&sect;31</termref><br/>time &ndash; mean Julian month &ndash; mo_j: <termref ref="para-31">&sect;31</termref><br/>time &ndash; mean Julian year &ndash; a_j: <termref ref="para-31">&sect;31</termref><br/>time &ndash; minute &ndash; min: <termref ref="para-31">&sect;31</termref><br/>time &ndash; month &ndash; mo: <termref ref="para-31">&sect;31</termref><br/>time &ndash; second &ndash; s: <termref ref="para-28">&sect;28</termref><br/>time &ndash; synodal month &ndash; mo_s: <termref ref="para-31">&sect;31</termref><br/>time &ndash; tropical year &ndash; a_t: <termref ref="para-31">&sect;31</termref><br/>time &ndash; week &ndash; wk: <termref ref="para-31">&sect;31</termref><br/>time &ndash; year &ndash; a: <termref ref="para-31">&sect;31</termref><br/>transmission rate,  signal &ndash; baud &ndash; Bd: <termref ref="para-48">&sect;48</termref><br/>tuberculin,  biologic activity of &ndash; tuberculin unit &ndash; [tb'U]: <termref ref="para-45">&sect;45</termref><br/>turbidity &ndash; Formazin Nephelometric Unit &ndash; [FNU]: <termref ref="para-47">&sect;47</termref><br/>turbidity &ndash; Nephelometric Turbidity Unit &ndash; [NTU]: <termref ref="para-47">&sect;47</termref><br/>unit,  Ehrlich &ndash; Ehrlich unit &ndash; [EU]: <termref ref="para-45">&sect;45</termref><br/>unit,  arbitrary ELISA &ndash; ELISA unit &ndash; [ELU]: <termref ref="para-45">&sect;45</termref><br/>using some reference standard,  procedure defined amount of an allergen &ndash; allergen unit &ndash; [AU]: <termref ref="para-45">&sect;45</termref><br/>using the Stallergenes&reg; method,  amount of an allergen calibrated through in-vivo testing &ndash; index of reactivity &ndash; [IR]: <termref ref="para-45">&sect;45</termref><br/>velocity &ndash; knot &ndash; [kn_br]: <termref ref="para-36">&sect;36</termref><br/>velocity &ndash; knot &ndash; [kn_i]: <termref ref="para-34">&sect;34</termref><br/>velocity &ndash; velocity of light &ndash; [c]: <termref ref="para-32">&sect;32</termref><br/>ventricular stroke work &ndash; gram-force meter per heartbeat &ndash; gf.m/{H.B.}: <termref ref="para-50">&sect;50</termref><br/>ventricular stroke work,  proportional to &ndash; gram meter per heartbeat &ndash; g.m/{H.B.}: <termref ref="para-50">&sect;50</termref><br/>view area in microscope &ndash; high power field &ndash; [HPF]: <termref ref="para-45">&sect;45</termref><br/>view area in microscope &ndash; low power field &ndash; [LPF]: <termref ref="para-45">&sect;45</termref><br/>viscosity,  dynamic &ndash; Poise &ndash; P: <termref ref="para-33">&sect;33</termref><br/>viscosity,  kinematic &ndash; Stokes &ndash; St: <termref ref="para-33">&sect;33</termref><br/>volume &ndash; board foot &ndash; [bf_i]: <termref ref="para-34">&sect;34</termref><br/>volume &ndash; bushel &ndash; [bu_br]: <termref ref="para-38">&sect;38</termref><br/>volume &ndash; cord &ndash; [cr_i]: <termref ref="para-34">&sect;34</termref><br/>volume &ndash; cubic foot &ndash; [cft_i]: <termref ref="para-34">&sect;34</termref><br/>volume &ndash; cubic inch &ndash; [cin_i]: <termref ref="para-34">&sect;34</termref><br/>volume &ndash; cubic yard &ndash; [cyd_i]: <termref ref="para-34">&sect;34</termref><br/>volume &ndash; cup &ndash; [cup_us]: <termref ref="para-37">&sect;37</termref><br/>volume &ndash; drop &ndash; [drp]: <termref ref="para-44">&sect;44</termref><br/>volume &ndash; fluid dram &ndash; [fdr_br]: <termref ref="para-38">&sect;38</termref><br/>volume &ndash; fluid ounce &ndash; [foz_br]: <termref ref="para-38">&sect;38</termref><br/>volume &ndash; gallon &ndash; [gal_br]: <termref ref="para-38">&sect;38</termref><br/>volume &ndash; gill &ndash; [gil_br]: <termref ref="para-38">&sect;38</termref><br/>volume &ndash; liter &ndash; L: <termref ref="para-31">&sect;31</termref><br/>volume &ndash; liter &ndash; l: <termref ref="para-31">&sect;31</termref><br/>volume &ndash; metric cup &ndash; [cup_m]: <termref ref="para-37">&sect;37</termref><br/>volume &ndash; metric tablespoon &ndash; [tbs_m]: <termref ref="para-37">&sect;37</termref><br/>volume &ndash; metric teaspoon &ndash; [tsp_m]: <termref ref="para-37">&sect;37</termref><br/>volume &ndash; minim &ndash; [min_br]: <termref ref="para-38">&sect;38</termref><br/>volume &ndash; peck &ndash; [pk_br]: <termref ref="para-38">&sect;38</termref><br/>volume &ndash; pint &ndash; [pt_br]: <termref ref="para-38">&sect;38</termref><br/>volume &ndash; quart &ndash; [qt_br]: <termref ref="para-38">&sect;38</termref><br/>volume &ndash; stere &ndash; st: <termref ref="para-47">&sect;47</termref><br/>volume &ndash; tablespoon &ndash; [tbs_us]: <termref ref="para-37">&sect;37</termref><br/>volume &ndash; teaspoon &ndash; [tsp_us]: <termref ref="para-37">&sect;37</termref><br/>volume,  dry &ndash; bushel &ndash; [bu_us]: <termref ref="para-37">&sect;37</termref><br/>volume,  dry &ndash; dry pint &ndash; [dpt_us]: <termref ref="para-37">&sect;37</termref><br/>volume,  dry &ndash; dry quart &ndash; [dqt_us]: <termref ref="para-37">&sect;37</termref><br/>volume,  dry &ndash; historical winchester gallon &ndash; [gal_wi]: <termref ref="para-37">&sect;37</termref><br/>volume,  dry &ndash; peck &ndash; [pk_us]: <termref ref="para-37">&sect;37</termref><br/>volume,  fluid &ndash; Queen&nbsp;Anne's wine gallon &ndash; [gal_us]: <termref ref="para-37">&sect;37</termref><br/>volume,  fluid &ndash; barrel &ndash; [bbl_us]: <termref ref="para-37">&sect;37</termref><br/>volume,  fluid &ndash; cord &ndash; [crd_us]: <termref ref="para-37">&sect;37</termref><br/>volume,  fluid &ndash; fluid dram &ndash; [fdr_us]: <termref ref="para-37">&sect;37</termref><br/>volume,  fluid &ndash; fluid ounce &ndash; [foz_us]: <termref ref="para-37">&sect;37</termref><br/>volume,  fluid &ndash; gill &ndash; [gil_us]: <termref ref="para-37">&sect;37</termref><br/>volume,  fluid &ndash; metric fluid ounce &ndash; [foz_m]: <termref ref="para-37">&sect;37</termref><br/>volume,  fluid &ndash; minim &ndash; [min_us]: <termref ref="para-37">&sect;37</termref><br/>volume,  fluid &ndash; pint &ndash; [pt_us]: <termref ref="para-37">&sect;37</termref><br/>volume,  fluid &ndash; quart &ndash; [qt_us]: <termref ref="para-37">&sect;37</termref><br/>water,  depth of &ndash; fathom &ndash; [fth_i]: <termref ref="para-34">&sect;34</termref><br/>work,  proportional to ventricular stroke &ndash; gram meter per heartbeat &ndash; g.m/{H.B.}: <termref ref="para-50">&sect;50</termref><br/>work,  ventricular stroke &ndash; gram-force meter per heartbeat &ndash; gf.m/{H.B.}: <termref ref="para-50">&sect;50</termref><br/>x-ray attenuation &ndash; Hounsfield unit &ndash; [hnsf'U]: <termref ref="para-44">&sect;44</termref><br/></td></tr></table></div2></div1><div1 ignore="no" id="datyp2apdxatblxmp"><head>Example Unit Terms</head><p>
        The following table lists example unit terms that are commonly used in
        medicine. Since the space of possible unit terms is infinite in theory
        and very large in practice, no attempt has been made on a systematic
        coverage of possible units. All necessary units can be built from the 
        rules of <emph>The Unified Code for Units of Measure</emph> and there is no need of a particular term to be
        enumerated in order to be valid.
      </p><p>
        The source of this table is the HL7 V2.4 table of units in chapter 7
        with many corrections and some modifications.
      </p><p>
        The columns are: (1) the case sensitive unit term and variants; (2) a
        plain text reading; (3) example use; (4) canonical form. The canonical
        form, consisting of 3 columns: (4.1) the magnitude value of the unit term in
        terms of the canonical unit; (4.2) a canonical unit term; (4.3) if
        applicable a special conversion function code.
      </p><note><p>
          When a special conversion function is specified, the conversion takes
          more than multiplication with a factor. Implementers should consult
          the UCUM specification or the reference implementation for details on
          how to apply these conversion functions.
        </p></note><p>
        The example unit terms are given with alternatives for the following
        reason. The source of the example terms is the HL7 version 2.4
        specification of chapter 7. To show the essential differences between
        UCUM and the HL7 version 2.4 codes, the first column shows unit terms
        that are as similar to the HL7 2.4 published terms as
        possible. However, the HL7 version 2.4 suggested unit terms were
        sometimes unnecessarily complicated (e.g., the unit 1 dyn cast as 10
        &mu;N; decimal factors instead of the standard multiplier prefixes,
        nested parenthetical terms in divisions, etc.), even sometimes
        suggesting deprecated conventional habits (e.g., using annotations
        like "/g{HGB}" instead of just "/g".)  Hence, the second column
        "alternative suggestions" lists equivalent unit terms that are either
        more straightforward or more appropriate or both.
      </p><!-- FIXME: this table could get out of date as things change, should be generated --><table><caption>Example Unit Terms by Term</caption><col width="1.06"/><col width="1.13"/><col width="1.56"/><col width="1.63"/><col width="2.25"/><col width="1.00"/><col width="0.44"/><thead><tr><th>unit term</th><th>suggested alternatives</th><th>name or "reading"</th><th>example use</th><th>canonical form value</th><th>canonical form unit</th><th>c.f. func</th></tr></thead><tbody><tr><td>/[arb'U]</td><td/><td>per arbitrary unit</td><td/><td>1</td><td>1</td><td/></tr><tr><td>/[HPF]</td><td/><td>per high power field</td><td/><td>1</td><td>1</td><td/></tr><tr><td>/[iU]</td><td/><td>per international unit</td><td/><td>1</td><td>1</td><td/></tr><tr><td>/{tot}</td><td/><td>per total count</td><td/><td>1</td><td>1</td><td/></tr><tr><td>/g{creat}</td><td>/g</td><td>per gram of creatinine</td><td/><td>1</td><td>g-1</td><td/></tr><tr><td>/g{HGB}</td><td>/g</td><td>per gram of hemoglobin</td><td/><td>1</td><td>g-1</td><td/></tr><tr><td>/g{tot'nit}</td><td>/g</td><td>per gram of total nitrogen</td><td/><td>1</td><td>g-1</td><td/></tr><tr><td>/g{tot'ptot}</td><td>/g</td><td>per gram of total protein</td><td/><td>1</td><td>g-1</td><td/></tr><tr><td>/g{wet'tis}</td><td>/g</td><td>per gram of wet tissue</td><td/><td>1</td><td>g-1</td><td/></tr><tr><td>/kg</td><td/><td>per kilogram</td><td/><td>0.001</td><td>g-1</td><td/></tr><tr><td>/kg{body'wt}</td><td>/kg</td><td>per kilogram body weight</td><td/><td>.001</td><td>g-1</td><td/></tr><tr><td>/L</td><td/><td>per liter</td><td/><td>1000</td><td>m-3</td><td/></tr><tr><td>/m2</td><td/><td>per square meter</td><td/><td>1</td><td>m-2</td><td/></tr><tr><td>/min</td><td/><td>per minute</td><td/><td>0.0166666666666667</td><td>s-1</td><td/></tr><tr><td>/mL</td><td/><td>per milliliter</td><td/><td>1000000</td><td>m-3</td><td/></tr><tr><td>/mL</td><td/><td>per milliliter</td><td/><td>1000000</td><td>m-3</td><td/></tr><tr><td>[iU]/d</td><td/><td>international unit per day</td><td/><td>1.15740740740741 &times; 10<emph role="sup">-5</emph></td><td>s-1</td><td/></tr><tr><td>[iU]/h</td><td/><td>international unit per hour</td><td/><td>0.000277777777777778</td><td>s-1</td><td/></tr><tr><td>[iU]/kg</td><td/><td>international unit per kilogram</td><td/><td>0.001</td><td>g-1</td><td/></tr><tr><td>[iU]/L</td><td/><td>international unit per liter</td><td/><td>1000</td><td>m-3</td><td/></tr><tr><td>[iU]/min</td><td/><td>international unit per minute</td><td/><td>0.0166666666666667</td><td>s-1</td><td/></tr><tr><td>[iU]/mL</td><td/><td>international unit per milliliter</td><td/><td>1000000</td><td>m-3</td><td/></tr><tr><td>10*12/L</td><td>/pL</td><td>trillion per liter</td><td/><td>10<emph role="sup">15</emph></td><td>m-3</td><td/></tr><tr><td>10*3.{RBC}</td><td>10*3</td><td>thousand red blood cells</td><td/><td>1000</td><td>1</td><td/></tr><tr><td>10*3/L</td><td>/mL</td><td>thousand per liter</td><td/><td>1000000</td><td>m-3</td><td/></tr><tr><td>10*3/mL</td><td>/uL</td><td>thousand per milliliter</td><td/><td>1000000000</td><td>m-3</td><td/></tr><tr><td>10*3/mm3</td><td>/nL</td><td>thousand cubic millimeter</td><td>white blood cell count</td><td>1000000000000</td><td>m-3</td><td/></tr><tr><td>10*6/L</td><td>/uL</td><td>million per liter</td><td/><td>1000000000</td><td>m-3</td><td/></tr><tr><td>10*6/mL</td><td>/nL</td><td>million per milliliter</td><td/><td>1000000000000</td><td>m-3</td><td/></tr><tr><td>10*6/mm3</td><td>/pL</td><td>million per cubic millimeter</td><td/><td>10<emph role="sup">15</emph></td><td>m-3</td><td/></tr><tr><td>10*9/L</td><td>/nL</td><td>billion per liter</td><td/><td>1000000000000</td><td>m-3</td><td/></tr><tr><td>10*9/mL</td><td>/pL</td><td>billion per milliliter</td><td/><td>10<emph role="sup">15</emph></td><td>m-3</td><td/></tr><tr><td>10*9/mm3</td><td>/fL</td><td>billion per cubic millimeter</td><td/><td>10<emph role="sup">18</emph></td><td>m-3</td><td/></tr><tr><td>10.L/(min.m2)</td><td>daL/min/m2</td><td>ten liter per minute and square meter (dekaliter per minute and square meter)</td><td/><td>0.000166666666666667</td><td>m.s-1</td><td/></tr><tr><td>10.L/min</td><td>daL/min</td><td>ten liter per minute (dekaliter per minute)</td><td/><td>0.000166666666666667</td><td>m3.s-1</td><td/></tr><tr><td>10.uN.s/(cm5.m2)</td><td>dyn.s/(cm5.m2) dyn.s/cm5/m2</td><td>dyne second per centimeter5 and square meter</td><td>systemic vascular resistance/body surface area</td><td>100000000</td><td>m-6.g.s-1</td><td/></tr><tr><td>10.uN.s/cm5</td><td>dyn.s/cm5</td><td>dyne second per centimeter5</td><td>systemic vascular resistance</td><td>100000000</td><td>m-4.g.s-1</td><td/></tr><tr><td>A/m</td><td/><td>ampere per meter</td><td/><td>1</td><td>m-1.s-1.C</td><td/></tr><tr><td>cm</td><td/><td>centimeter</td><td/><td>0.01</td><td>m</td><td/></tr><tr><td>cm[H2O]</td><td/><td>centimeter H2O</td><td/><td>98066.5</td><td>m-1.g.s-2</td><td/></tr><tr><td>cm[H2O].s/L</td><td>cm[H2O]/(L/s)</td><td>centimeter H20 per ( liter per second ) (centimeter H20 second per liter)</td><td>mean pulmonary resistance</td><td>98066500</td><td>m-4.g.s-1</td><td/></tr><tr><td>cm[H2O]/(s.m)</td><td>cm[H2O]/s/m</td><td>centimeter H20 per second and meter</td><td>pulmonary pressure time product</td><td>98066.5</td><td>m-2.g.s-3</td><td/></tr><tr><td>cm2/s</td><td/><td>square centimeter per second</td><td/><td>0.0001</td><td>m2.s-1</td><td/></tr><tr><td>dm2/s2</td><td/><td>square dekameter per square second</td><td/><td>0.01</td><td>m2.s-2</td><td/></tr><tr><td>fg</td><td/><td>femtogram</td><td/><td>10-15</td><td>g</td><td/></tr><tr><td>fL</td><td/><td>femtoliter</td><td/><td>10-18</td><td>m3</td><td/></tr><tr><td>fmol</td><td/><td>femtomole</td><td/><td>602214076</td><td>1</td><td/></tr><tr><td>g.m</td><td/><td>gram meter</td><td/><td>1</td><td>m.g</td><td/></tr><tr><td>gf.m</td><td/><td>gram-force meter</td><td/><td>9.80665</td><td>m2.s-2.g</td><td/></tr><tr><td>gf.m/({hb}.m2)</td><td>gf.m/{hb}/m2 gf/m</td><td>gram-force meter per heartbeat and square meter</td><td/><td>9.80665</td><td>s-2.g</td><td/></tr><tr><td>gf.m/{hb}</td><td>gf.m</td><td>gram-force meter per heartbeat</td><td>ventricular stroke work</td><td>9.80665</td><td>m2.s-2.g</td><td/></tr><tr><td>g/(8.h)</td><td/><td>gram per 8-hour shift</td><td/><td>3.47222222222222 &times; 10<emph role="sup">-5</emph></td><td>g.s-1</td><td/></tr><tr><td>g/(8.kg.h)</td><td>g/kg/(8.h) 125/h</td><td>gram per kilogram and 8-hour shift</td><td>mass dose rate per body mass</td><td>3.47222222222222 &times; 10<emph role="sup">-8</emph></td><td>s-1</td><td/></tr><tr><td>g/(kg.d)</td><td>g/kg/d</td><td>gram per kilogram and day</td><td>mass dose rate  per body mass</td><td>1.15740740740741 &times; 10<emph role="sup">-8</emph></td><td>s-1</td></tr><tr><td>g/(kg.h)</td><td>g/kg/h 10*-3/h</td><td>gram per kilogram and hour</td><td>mass dose rate per body mass</td><td>2.77777777777778 &times; 10<emph role="sup">-7</emph></td><td>s-1</td><td/></tr><tr><td>g/(kg.min)</td><td>g/kg/min 10*-3/min</td><td>gram per kilogram and minute</td><td>mass dose rate per body mass</td><td>1.66666666666667 &times; 10<emph role="sup">-5</emph></td><td>s-1</td><td/></tr><tr><td>g/d</td><td/><td>gram per day</td><td/><td>1.15740740740741 &times; 10<emph role="sup">-5</emph></td><td>g.s-1</td><td/></tr><tr><td>g/dL</td><td/><td>gram per deciliter</td><td/><td>10000</td><td>m-3.g</td><td/></tr><tr><td>g/h</td><td/><td>gram per hour</td><td/><td>0.000277777777777778</td><td>g.s-1</td><td/></tr><tr><td>g/kg</td><td>1/1000</td><td>gram per kilogram</td><td>mass dose per body mass</td><td>0.001</td><td>1</td><td/></tr><tr><td>g/L</td><td/><td>gram per liter</td><td/><td>1000</td><td>m-3.g</td><td/></tr><tr><td>g/m2</td><td/><td>gram per square meter</td><td>mass does per body surface area</td><td>1</td><td>m-2.g</td><td/></tr><tr><td>g/min</td><td/><td>gram per minute</td><td/><td>0.0166666666666667</td><td>g.s-1</td><td/></tr><tr><td>hL</td><td/><td>hectoliter</td><td/><td>0.1</td><td>m3</td><td/></tr><tr><td>J/L</td><td/><td>joule per liter</td><td> work of breathing</td><td>1000000</td><td>m-1.g.s-2</td><td/></tr><tr><td>K/W</td><td/><td>kelvin per watt</td><td/><td>0.001</td><td>m-2.g-1.s3.K</td><td/></tr><tr><td>kat/kg</td><td/><td>katal per kilogram</td><td/><td>6.02214076 &times; 10<emph role="sup">20</emph></td><td>g-1.s-1</td><td/></tr><tr><td>kat/L</td><td/><td>katal per liter</td><td/><td>6.02214076 &times; 10<emph role="sup">26</emph></td><td>m-3.s-1</td><td/></tr><tr><td>kcal</td><td/><td>kilocalorie</td><td/><td>4184000</td><td>m2.g.s-2</td><td/></tr><tr><td>kcal/(8.h)</td><td/><td>kilocalorie per 8-hour shift</td><td/><td>145.277777777778</td><td>m2.g.s-3</td><td/></tr><tr><td>kcal/d</td><td/><td>kilocalorie per day</td><td/><td>48.4259259259259</td><td>m2.g.s-3</td><td/></tr><tr><td>kcal/h</td><td/><td>kilocalorie per hour</td><td/><td>1162.22222222222</td><td>m2.g.s-3</td><td/></tr><tr><td>kg</td><td/><td>kilogram</td><td/><td>1000</td><td>g</td><td/></tr><tr><td>kg.m/s</td><td/><td>kilogram meter per second</td><td/><td>1000</td><td>m.g.s-1</td><td/></tr><tr><td>kg/(s.m2)</td><td/><td>kilogram per second and square meter</td><td/><td>1000</td><td>m-2.g.s-1</td><td/></tr><tr><td>kg/h</td><td/><td>kilogram per hour</td><td/><td>0.277777777777778</td><td>g.s-1</td><td/></tr><tr><td>kg/L</td><td/><td>kilogram per liter</td><td/><td>1000000</td><td>m-3.g</td><td/></tr><tr><td>kg/m2</td><td/><td>kilogram per square meter</td><td/><td>1000</td><td>m-2.g</td><td/></tr><tr><td>kg/m3</td><td/><td>kilogram per cubic meter</td><td/><td>1000</td><td>m-3.g</td><td/></tr><tr><td>kg/min</td><td/><td>kilogram per minute</td><td/><td>16.6666666666667</td><td>g.s-1</td><td/></tr><tr><td>kg/mol</td><td/><td>kilogram per mole</td><td/><!-- FIXME: there is something wrong with this as the number doesn't match what we had for the AMU --><td>1.66054018667494 &times; 10<emph role="sup">-21</emph></td><td>g</td><td/></tr><tr><td>kg/s</td><td/><td>kilogram per second</td><td/><td>1000</td><td>g.s-1</td><td/></tr><tr><td>kPa</td><td/><td>kilopascal</td><td/><td>1000000</td><td>m-1.g.s-2</td><td/></tr><tr><td>ks</td><td/><td>kilosecond</td><td/><td>1000</td><td>s</td><td/></tr><tr><td>L.s2/s</td><td>L.s</td><td>liter square second per second</td><td/><td>0.001</td><td>m3.s</td><td/></tr><tr><td>L/(8.h)</td><td/><td>liter per 8-hour shift</td><td/><td>3.47222222222222 &times; 10<emph role="sup">-8</emph></td><td>m3.s-1</td><td/></tr><tr><td>L/(min.m2)</td><td/><td>liter per minute and square meter</td><td>cardiac index (cardiac output per body surface area)</td><td>1.66666666666667 &times; 10<emph role="sup">-5</emph></td><td>m.s-1</td><td/></tr><tr><td>L/d</td><td/><td>liter per day</td><td/><td>1.15740740740741 &times; 10<emph role="sup">-8</emph></td><td>m3.s-1</td><td/></tr><tr><td>L/h</td><td/><td>liter per hour</td><td/><td>2.77777777777778 &times; 10<emph role="sup">-7</emph></td><td>m3.s-1</td><td/></tr><tr><td>L/kg</td><td/><td>liter per kilogram</td><td/><td>10-6</td><td>m3.g-1</td><td/></tr><tr><td>L/min</td><td/><td>liter per minute</td><td/><td>1.66666666666667 &times; 10<emph role="sup">-5</emph></td><td>m3.s-1</td><td/></tr><tr><td>L/s</td><td/><td>liter per second</td><td>peak expiratory flow</td><td>0.001</td><td>m3.s-1</td><td/></tr><tr><td>lm/m2</td><td/><td>lumen per square meter</td><td/><td>1</td><td>m-2.rad2.cd</td><td/></tr><tr><td>m/s</td><td/><td>meter per second</td><td/><td>1</td><td>m.s-1</td><td/></tr><tr><td>m/s2</td><td/><td>meter per square second</td><td/><td>1</td><td>m.s-2</td><td/></tr><tr><td>m[iU]/mL</td><td/><td>milli-international unit per milliliter</td><td/><td>1000</td><td>m-3</td><td/></tr><tr><td>m2</td><td/><td>square meter</td><td>body surface area</td><td>1</td><td>m2</td><td/></tr><tr><td>m2/s</td><td/><td>square meter per second</td><td/><td>1</td><td>m2.s-1</td><td/></tr><tr><td>m3/s</td><td/><td>cubic meter per second</td><td/><td>1</td><td>m3.s-1</td><td/></tr><tr><td>mbar</td><td/><td>millibar</td><td/><td>100000</td><td>m-1.g.s-2</td><td/></tr><tr><td>mbar.s/L</td><td>mbar/(L.s)</td><td>millibar per (liter per second) = millibar second per liter</td><td>expiratory resistance</td><td>100000000</td><td>m-4.g.s-1</td><td/></tr><tr><td>meq</td><td/><td>milliequivalent</td><td/><td>6.02214076 &times; 10<emph role="sup">20</emph></td><td>1</td><td/></tr><tr><td>meq/(8.h)</td><td/><td>milliequivalent per 8-hour shift</td><td/><td>2.0910196875 &times; 10<emph role="sup">16</emph></td><td>s-1</td><td/></tr><tr><td>meq/(8.h.kg)</td><td>meq/kg/(8.h)</td><td>milliequivalent per kilogram and 8-hour shift</td><td>dose rate per patient body mass</td><td>20910196875000</td><td>g-1.s-1</td><td/></tr><tr><td>meq/(kg.d)</td><td>meq/kg/d</td><td>milliequivalent per kilogram per day</td><td>dose rate per patient body mass</td><td>6970065625000</td><td>g-1.s-1</td><td/></tr><tr><td>meq/(kg.h)</td><td>meq/kg/h</td><td>milliequivalent per kilogram per hour</td><td>dose rate per patient body mass</td><td>167281575000000</td><td>g-1.s-1</td><td/></tr><tr><td>meq/(kg.min)</td><td>meq/kg/min</td><td>milliequivalent per kilogram and minute</td><td>dose rate per patient body mass</td><td>1.00368945 &times; 10<emph role="sup">16</emph></td><td>g-1.s-1</td><td/></tr><tr><td>meq/d</td><td/><td>milliequivalent per day</td><td/><td>6.970065625 &times; 10<emph role="sup">15</emph></td><td>s-1</td><td/></tr><tr><td>meq/h</td><td/><td>milliequivalent per hour</td><td/><td>1.67281575 &times; 10<emph role="sup">17</emph></td><td>s-1</td><td/></tr><tr><td>meq/kg</td><td/><td>milliequivalent per kilogram</td><td>dose per patient body mass</td><td>6.02214076 &times; 10<emph role="sup">17</emph></td><td>g-1</td><td/></tr><tr><td>meq/L</td><td/><td>milliequivalent per liter</td><td/><td>6.02214076 &times; 10<emph role="sup">23</emph></td><td>m-3</td><td/></tr><tr><td>meq/m2</td><td/><td>milliequivalent per square meter</td><td>dose per patient body surface area</td><td>6.02214076 &times; 10<emph role="sup">20</emph></td><td>m-2</td><td/></tr><tr><td>meq/min</td><td/><td>milliequivalent per minute</td><td/><td>1.00368945 &times; 10<emph role="sup">19</emph></td><td>s-1</td><td/></tr><tr><td>mg</td><td/><td>milligram</td><td/><td>0.001</td><td>g</td><td/></tr><tr><td>mg/(8.h)</td><td/><td>milligram per 8-hour shift</td><td/><td>3.47222222222222 &times; 10<emph role="sup">-8</emph></td><td>g.s-1</td><td/></tr><tr><td>mg/(8.h.kg)</td><td>mg/kg/(8.h) 10*-6/(8.h)</td><td>milligram per kilogram and 8-hour shift</td><td>mass dose rate per patient body mass</td><td>3.47222222222222 &times; 10<emph role="sup">-11</emph></td><td>s-1</td><td/></tr><tr><td>mg/(kg.d)</td><td>mg/kg/d 10*-6/d</td><td>milligram per kilogram and day</td><td>mass dose rate per patient body mass</td><td>1.15740740740741 &times; 10<emph role="sup">-11</emph></td><td>s-1</td><td/></tr><tr><td>mg/(kg.h)</td><td>mg/kg/h 10*-6/h</td><td>milligram per kilogram and hour</td><td>mass dose rate  per patient body mass</td><td>2.77777777777778 &times; 10<emph role="sup">-10</emph></td><td>s-1</td><td/></tr><tr><td>mg/(kg.min)</td><td>mg/kg/min 10*-6/min</td><td>milligram per kilogram and minute</td><td>mass dose rate per patient body mass</td><td>1.66666666666667 &times; 10<emph role="sup">-8</emph></td><td>s-1</td><td/></tr><tr><td>mg/d</td><td/><td>milligram per day</td><td/><td>1.15740740740741 &times; 10<emph role="sup">-8</emph></td><td>g.s-1</td><td/></tr><tr><td>mg/dL</td><td/><td>milligram per deciliter</td><td/><td>10</td><td>m-3.g</td><td/></tr><tr><td>mg/h</td><td/><td>milligram per hour</td><td/><td>2.77777777777778 &times; 10<emph role="sup">-7</emph></td><td>g.s-1</td><td/></tr><tr><td>mg/kg</td><td>10*-6</td><td>milligram per kilogram</td><td/><td>10-6</td><td>1</td><td/></tr><tr><td>mg/L</td><td/><td>milligram per liter</td><td/><td>1</td><td>m-3.g</td><td/></tr><tr><td>mg/m2</td><td/><td>milligram per square meter</td><td>mass dose per patient body surface area</td><td>0.001</td><td>m-2.g</td><td/></tr><tr><td>mg/m3</td><td/><td>milligram per cubic meter</td><td/><td>0.001</td><td>m-3.g</td><td/></tr><tr><td>mg/min</td><td/><td>milligram per minute</td><td/><td>1.66666666666667 &times; 10<emph role="sup">-5</emph></td><td>g.s-1</td><td/></tr><tr><td>mL</td><td/><td>milliliter</td><td/><td>10-6</td><td>m3</td><td/></tr><tr><td>mL/({h'b}.m2)</td><td>mL/m2</td><td>milliliter per heartbeat per square meter</td><td>ventricular stroke volume index</td><td>10-6</td><td>m</td><td/></tr><tr><td>mL/(8.h)</td><td/><td>milliliter per 8-hour shift</td><td/><td>3.47222222222222 &times; 10<emph role="sup">-11</emph></td><td>m3.s-1</td><td/></tr><tr><td>mL/(8.h.kg)</td><td>mL/kg/(8.h)</td><td>milliliter per kilogram and 8-hour shift</td><td>renal excretion volume rate per body mass</td><td>3.47222222222222 &times; 10<emph role="sup">-14</emph></td><td>m3.g-1.s-1</td><td/></tr><tr><td>mL/(kg.d)</td><td>mL/kg/d</td><td>milliliter per kilogram and day</td><td>renal excretion volume rate per body mass</td><td>1.15740740740741 &times; 10<emph role="sup">-14</emph></td><td>m3.g-1.s-1</td><td/></tr><tr><td>mL/(kg.h)</td><td>mL/kg/h</td><td>milliliter per kilogram and hour</td><td>renal excretion volume rate per body mass</td><td>2.77777777777778 &times; 10<emph role="sup">-13</emph></td><td>m3.g-1.s-1</td><td/></tr><tr><td>mL/(kg.min)</td><td>mL/kg/min</td><td>milliliter per kilogram and minute</td><td>respiratory volume rate per body mass</td><td>1.66666666666667 &times; 10<emph role="sup">-11</emph></td><td>m3.g-1.s-1</td><td/></tr><tr><td>mL/(min.m2)</td><td>mL/m2/min</td><td>milliliter per minute and square meter</td><td>volume per body surface area; oxygen consumption index</td><td>1.66666666666667 &times; 10<emph role="sup">-8</emph></td><td>m.s-1</td><td/></tr><tr><td>mL/{h'b}</td><td/><td>milliliter per heartbeat</td><td>stroke volume</td><td>10-6</td><td>m3</td><td/></tr><tr><td>mL/cm[H2O]</td><td/><td>milliliter per centimeters H20</td><td>dynamic lung compliance</td><td>1.01971621297793 &times; 10<emph role="sup">-11</emph></td><td>m4.g-1.s2</td><td/></tr><tr><td>mL/d</td><td/><td>milliliter per day</td><td/><td>1.15740740740741 &times; 10<emph role="sup">-11</emph></td><td>m3.s-1</td><td/></tr><tr><td>mL/h</td><td/><td>milliliter per hour</td><td/><td>2.77777777777778 &times; 10<emph role="sup">-10</emph></td><td>m3.s-1</td><td/></tr><tr><td>mL/kg</td><td/><td>milliliter per kilogram</td><td>tidal volume per body mass</td><td>10-9</td><td>m3.g-1</td><td/></tr><tr><td>mL/m2</td><td/><td>milliliter per square meter</td><td>volume per patient body surface area</td><td>10-6</td><td>m</td><td/></tr><tr><td>mL/mbar</td><td/><td>milliliter per millibar</td><td>dynamic lung compliance</td><td>10-11</td><td>m4.g-1.s2</td><td/></tr><tr><td>mL/min</td><td/><td>milliliter per minute</td><td/><td>1.66666666666667 &times; 10<emph role="sup">-8</emph></td><td>m3.s-1</td><td/></tr><tr><td>mL/s</td><td/><td>milliliter per second</td><td/><td>10-6</td><td>m3.s-1</td><td/></tr><tr><td>mm</td><td/><td>millimeter</td><td/><td>0.001</td><td>m</td><td/></tr><tr><td>mm/h</td><td/><td>millimeter hour</td><td/><td>2.77777777777778 &times; 10<emph role="sup">-7</emph></td><td>m.s-1</td><td/></tr><tr><td>mm[Hg]</td><td/><td>millimeter Mercury column</td><td/><td>133322</td><td>m-1.g.s-2</td><td/></tr><tr><td>mmol/(8.h)</td><td/><td>millimole per 8-hour shift</td><td/><td>2.0910196875 &times; 10<emph role="sup">16</emph></td><td>s-1</td><td/></tr><tr><td>mmol/(8.h.kg)</td><td>mmol/kg/(8.h)</td><td>millimole per kilogram and 8-hour shift</td><td>molar dose rate per patient body mass</td><td>20910196875000</td><td>g-1.s-1</td><td/></tr><tr><td>mmol/(kg.d)</td><td>mmol/kg/d</td><td>millimole per kilogram and day</td><td>molar dose rate per patient body mass</td><td>6970065625000</td><td>g-1.s-1</td><td/></tr><tr><td>mmol/(kg.h)</td><td>mmol/kg/h</td><td>millimole per kilogram and hour</td><td>molar dose rate per patient body mass</td><td>167281575000000</td><td>g-1.s-1</td><td/></tr><tr><td>mmol/(kg.min)</td><td>mmol/kg/min</td><td>millimole per kilogram and minute</td><td>molar dose rate per patient body mass</td><td>1.00368945 &times; 10<emph role="sup">16</emph></td><td>g-1.s-1</td><td/></tr><tr><td>mmol/h</td><td/><td>millimole per hour</td><td/><td>1.67281575 &times; 10<emph role="sup">17</emph></td><td>s-1</td><td/></tr><tr><td>mmol/kg</td><td/><td>millimole per kilogram</td><td>molar dose per patient body mass</td><td>6.02214076 &times; 10<emph role="sup">17</emph></td><td>g-1</td><td/></tr><tr><td>mmol/L</td><td/><td>millimole per liter</td><td/><td>6.02214076 &times; 10<emph role="sup">23</emph></td><td>m-3</td><td/></tr><tr><td>mmol/m2</td><td/><td>millimole per square meter</td><td>molar dose per patient body surface area</td><td>6.02214076 &times; 10<emph role="sup">20</emph></td><td>m-2</td><td/></tr><tr><td>mmol/min</td><td/><td>millimole per minute</td><td/><td>1.00368945 &times; 10<emph role="sup">19</emph></td><td>s-1</td><td/></tr><tr><td>mol/(kg.s)</td><td>mol/kg/s</td><td>mole per kilogram and second</td><td/><td>6.02214076 &times; 10<emph role="sup">20</emph></td><td>g-1.s-1</td><td/></tr><tr><td>mol/kg</td><td/><td>mole per Kilogram</td><td/><td>6.02214076 &times; 10<emph role="sup">20</emph></td><td>g-1</td><td/></tr><tr><td>mol/L</td><td/><td>mole per liter</td><td/><td>6.02214076 &times; 10<emph role="sup">26</emph></td><td>m-3</td><td/></tr><tr><td>mol/m3</td><td/><td>mole per cubic meter</td><td/><td>6.02214076 &times; 10<emph role="sup">23</emph></td><td>m-3</td><td/></tr><tr><td>mol/s</td><td/><td>mole per second</td><td/><td>6.02214076 &times; 10<emph role="sup">23</emph></td><td>s-1</td><td/></tr><tr><td>mosm/L</td><td/><td>milliosmole per liter</td><td/><td>6.02214076 &times; 10<emph role="sup">23</emph></td><td>m-3</td><td/></tr><tr><td>Ms</td><td/><td>megasecond</td><td/><td>1000000</td><td>s</td><td/></tr><tr><td>ms</td><td/><td>millisecond</td><td/><td>0.001</td><td>s</td><td/></tr><tr><td>mV</td><td/><td>millivolt</td><td/><td>1</td><td>m2.g.s-2.C-1</td><td/></tr><tr><td>N.s</td><td/><td>newton second</td><td/><td>1000</td><td>m.g.s-1</td><td/></tr><tr><td>ng</td><td/><td>nanogram</td><td/><td>10-9</td><td>g</td><td/></tr><tr><td>ng/(8.h)</td><td/><td>nanogram per 8-hour shift</td><td/><td>3.47222222222222 &times; 10<emph role="sup">-14</emph></td><td>g.s-1</td><td/></tr><tr><td>ng/(8.h.kg)</td><td>ng/kg/(8.h)</td><td>nanogram per kilogram  and 8-hour shift</td><td>mass dose rate per patient body mass</td><td>3.47222222222222 &times; 10<emph role="sup">-17</emph></td><td>s-1</td><td/></tr><tr><td>ng/(kg.d)</td><td>ng/kg/d</td><td>nanogram per kilogram and day</td><td>mass dose rate per patient body mass</td><td>1.15740740740741 &times; 10<emph role="sup">-17</emph></td><td>s-1</td><td/></tr><tr><td>ng/(kg.h)</td><td>ng/kg/h</td><td>nanogram per kilogram and hour</td><td>mass dose rate per patient body mass</td><td>2.77777777777778 &times; 10<emph role="sup">-16</emph></td><td>s-1</td><td/></tr><tr><td>ng/(kg.min)</td><td>ng/kg/min</td><td>nanogram per kilogram and minute</td><td>mass dose rate per patient body mass</td><td>1.66666666666667 &times; 10<emph role="sup">-14</emph></td><td>s-1</td><td/></tr><tr><td>ng/d</td><td/><td>nanogram per day</td><td/><td>1.15740740740741 &times; 10<emph role="sup">-14</emph></td><td>g.s-1</td><td/></tr><tr><td>ng/h</td><td/><td>nanogram per hour</td><td/><td>2.77777777777778 &times; 10<emph role="sup">-13</emph></td><td>g.s-1</td><td/></tr><tr><td>ng/kg</td><td/><td>nanogram per kilogram</td><td>mass dose per patient body mass</td><td>10-12</td><td>1</td><td/></tr><tr><td>ng/L</td><td/><td>nanogram per liter</td><td/><td>10-6</td><td>m-3.g</td><td/></tr><tr><td>ng/m2</td><td/><td>nanogram per square meter</td><td>mass dose per patient body surface area</td><td>10-9</td><td>m-2.g</td><td/></tr><tr><td>ng/min</td><td/><td>nanogram per minute</td><td/><td>1.66666666666667 &times; 10<emph role="sup">-11</emph></td><td>g.s-1</td><td/></tr><tr><td>ng/mL</td><td/><td>nanogram  per milliliter</td><td/><td>0.001</td><td>m-3.g</td><td/></tr><tr><td>ng/s</td><td/><td>nanogram per second</td><td/><td>10-9</td><td>g.s-1</td><td/></tr><tr><td>nkat</td><td/><td>nanokatal</td><td/><td>602214076000000</td><td>s-1</td><td/></tr><tr><td>nm</td><td/><td>nanometer</td><td/><td>10-9</td><td>m</td><td/></tr><tr><td>nmol/s</td><td/><td>nanomole per second</td><td/><td>602214076000000</td><td>s-1</td><td/></tr><tr><td>ns</td><td/><td>nanosecond</td><td/><td>10-9</td><td>s</td><td/></tr><tr><td>Ohm.m</td><td/><td>ohm meter</td><td/><td>1000</td><td>m3.g.s-1.C-2</td><td/></tr><tr><td>osm/kg</td><td/><td>osmole per kilogram</td><td/><td>6.02214076 &times; 10<emph role="sup">20</emph></td><td>g-1</td><td/></tr><tr><td>osm/L</td><td/><td>osmole per liter</td><td/><td>6.02214076 &times; 10<emph role="sup">26</emph></td><td>m-3</td><td/></tr><tr><td>pA</td><td/><td>picoampere</td><td/><td>10-12</td><td>s-1.C</td><td/></tr><tr><td>pg</td><td/><td>picogram</td><td/><td>10-12</td><td>g</td><td/></tr><tr><td>pg/L</td><td/><td>picogram per liter</td><td/><td>10-9</td><td>m-3.g</td><td/></tr><tr><td>pg/mL</td><td/><td>picogram per milliliter</td><td/><td>10-6</td><td>m-3.g</td><td/></tr><tr><td>pkat</td><td/><td>picokatal</td><td/><td>602214076000</td><td>s-1</td><td/></tr><tr><td>pm</td><td/><td>picometer</td><td/><td>10-12</td><td>m</td><td/></tr><tr><td>pmol</td><td/><td>picomole</td><td/><td>602214076000</td><td>1</td><td/></tr><tr><td>ps</td><td/><td>picosecond</td><td/><td>10-12</td><td>s</td><td/></tr><tr><td>pT</td><td/><td>picotesla</td><td/><td>10-9</td><td>g.s-1.C-1</td><td/></tr><tr><td>u[iU]</td><td/><td>micro international unit</td><td/><td>10-6</td><td>1</td><td/></tr><tr><td>ueq</td><td/><td>microequivalents</td><td/><td>6.02214076 &times; 10<emph role="sup">17</emph></td><td>1</td><td/></tr><tr><td>ug</td><td/><td>microgram</td><td/><td>10-6</td><td>g</td><td/></tr><tr><td>ug/(8.h)</td><td/><td>microgram per 8-hour shift</td><td/><td>3.47222222222222 &times; 10<emph role="sup">-11</emph></td><td>g.s-1</td><td/></tr><tr><td>ug/(kg.d)</td><td>ug/kg/d</td><td>microgram per kilogram and day</td><td>mass dose rate per patient body mass</td><td>1.15740740740741 &times; 10<emph role="sup">-14</emph></td><td>s-1</td><td/></tr><tr><td>ug/(kg.h)</td><td>ug/kg/h</td><td>microgram per kilogram and hour</td><td>mass dose rate  per patient body mass</td><td>2.77777777777778 &times; 10<emph role="sup">-13</emph></td><td>s-1</td><td/></tr><tr><td>ug/(kg.min)</td><td>ug/kg/min</td><td>microgram per kilogram and minute</td><td>mass dose rate per patient body mass</td><td>1.66666666666667 &times; 10<emph role="sup">-11</emph></td><td>s-1</td><td/></tr><tr><td>ug/d</td><td/><td>microgram per day</td><td/><td>1.15740740740741 &times; 10<emph role="sup">-11</emph></td><td>g.s-1</td><td/></tr><tr><td>ug/dL</td><td/><td>microgram per deciliter</td><td/><td>0.01</td><td>m-3.g</td><td/></tr><tr><td>ug/g</td><td/><td>microgram per gram</td><td/><td>10-6</td><td>1</td><td/></tr><tr><td>ug/h</td><td/><td>microgram per hour</td><td/><td>2.77777777777778 &times; 10<emph role="sup">-10</emph></td><td>g.s-1</td><td/></tr><tr><td>ug/kg</td><td/><td>microgram per kilogram</td><td/><td>10-9</td><td>1</td><td/></tr><tr><td>ug/kg/(8.h)</td><td/><td>microgram per kilogram and 8-hour shift</td><td>mass dose rate per patient body mass</td><td>3.47222222222222 &times; 10<emph role="sup">-14</emph></td><td>s-1</td><td/></tr><tr><td>ug/L</td><td/><td>microgram per liter</td><td/><td>0.001</td><td>m-3.g</td><td/></tr><tr><td>ug/m2</td><td/><td>microgram per square meter</td><td>mass dose per patient body surface area</td><td>10-6</td><td>m-2.g</td><td/></tr><tr><td>ug/min</td><td/><td>microgram per minute</td><td/><td>1.66666666666667 &times; 10<emph role="sup">-8</emph></td><td>g.s-1</td><td/></tr><tr><td>ukat</td><td/><td>microkatal</td><td/><td>6.02214076 &times; 10<emph role="sup">17</emph></td><td>s-1</td><td/></tr><tr><td>um</td><td/><td>micrometer</td><td/><td>10-6</td><td>m</td><td/></tr><tr><td>umol</td><td/><td>micromole</td><td/><td>6.02214076 &times; 10<emph role="sup">17</emph></td><td>1</td><td/></tr><tr><td>umol/d</td><td/><td>micromole per day</td><td/><td>6970065625000</td><td>s-1</td><td/></tr><tr><td>umol/L</td><td/><td>micromole per liter</td><td/><td>6.02214076 &times; 10<emph role="sup">20</emph></td><td>m-3</td><td/></tr><tr><td>umol/min</td><td/><td>micromole per minute</td><td/><td>1.00368945 &times; 10<emph role="sup">16</emph></td><td>s-1</td><td/></tr><tr><td>us</td><td/><td>microsecond</td><td/><td>10-6</td><td>s</td><td/></tr><tr><td>uV</td><td/><td>microvolt</td><td/><td>0.001</td><td>m2.g.s-2.C-1</td><td/></tr></tbody></table></div1><div1 ignore="no" id="license"><head>Copyright and License Terms of Use</head><p>
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