The Unified Code for Units of Measure (UCUM) is a code system intended to include all 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 The Unified Code for Units of Measure are electronic data interchange (EDI) protocols, but there is nothing that prevents it from being used in other types of machine communication.
The UCUM website is available at https://ucum.org.
We would like to understand your use of UCUM, specifically any adverse limitations imposed by the current license. Our goal is a license that permits legitimate use of UCUM while maintaining its free nature and ensuring its longevity as an international standard. We ask that you complete a brief survey on our website.
Regenstrief Institute and the UCUM Committee are excited to announce the release of UCUM version 2.2, now available from the UCUM website and UCUM's GitHub repository. UCUM 2.2 adds two new units:
- [NTU] for Nephelometric Turbidity Unit
- [FNU] for Formazin Turbidity Unit
A number of constants represented in the specification have been updated per NIST. These include:
- Newtonian constant of gravitation
- Boltzmann constant
- elementary charge
- vacuum electric permittivity
- Avogadro's constant and associated values including atomic mass constant
- proton mass
- electron mass
Additionally, this release corrects a number of misspellings and typographic errors.
This is the first release of UCUM since May 2017 and the first using GitHub. We will continue to address outstanding issues and entertain requests for new units. We welcome your requests and feedback in the form of New Issues or New Discussions. While an official cadence has yet to be established, our intent is to provide the next release of UCUM later in 2024.
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