8 Different Types of Electrical Testers and How to Choose One

Non-Contact Voltage Tester (Inductance Tester)

• Best for: Detecting and measuring voltage

Non-contact voltage testers (inductance testers) allow you to check for voltage in wires or devices without touching any electrical parts. They are safe, easy to use, and inexpensive. 

The device is like a mini wand with a small tip that senses voltage in electrical wiring, outlets, circuit breakers, lamp cords, light sockets, and switches. You can get a reading simply by sticking the tip of the tester into an outlet slot or even touching the outside of a wire or electrical cable. 

Most models inform you of the voltage present with a red light at the tip of the tester and a buzzing sound. The most basic models indicate only whether any voltage is present. More sophisticated (and more expensive) types provide a rudimentary measurement of how much voltage is present. However, the measurement is not nearly as precise as other testers.

Neon Voltage Tester

• Best for: Detecting voltage, testing for grounded outlets

Neon voltage testers, or neon circuit testers, tell you only whether voltage is present; they don't tell you how much voltage is in a circuit. They have a small body with a neon light inside, and two short wire leads with a metal probe on each end. This device does not use a battery, making it a dependable tool. It is also inexpensive.

To use a neon voltage tester, touch one tester probe to a hot wire, screw terminal, or outlet slot. Touch the other probe to a neutral or ground contact. The small neon bulb in the tool's tip will light up if current is present.

The tester can also verify whether an outlet is properly grounded. If the tester lights up when the probes are inserted into the hot and neutral slots on the outlet but fails to light up when the probe is moved from the neutral to the grounding slot, it means the outlet is not grounded correctly. 

Plug-In Circuit Analyzer

• Best for: Testing grounded outlets

Plug-in circuit analyzers are inexpensive, easy-to-use testers that can tell you a great deal about a circuit's functions when you plug them into an electrical outlet. These devices are designed to test grounded outlets with three slots; they can't be used on older two-slot outlets.

Plug-in circuit analyzers have three neon lights in different patterns to indicate specific test results. A chart sticker on the tester helps you interpret the light patterns. Different light combinations signify a correctly wired outlet, a reverse-wired outlet, an open circuit, and the presence or lack of a ground connection.

Circuit analyzers do not have batteries; they simply plug into the outlet to perform the test. The outlet must have power for the tester to work.

There are new, more sophisticated plug-in circuit analyzers that also display the voltage and circuit conditions on an LCD screen. This new type requires batteries or recharging.

Continuity Tester

• Best for: Testing circuit continuity

A continuity tester is an inexpensive battery-powered device with a probe at one end and a cord with either an alligator clip or another probe at the other end. You touch each end at two points along an electrical path. If a light is illuminated on the tester's body, it means you have completed a circuit. Some units also make sounds if there is a complete circuit.

Unlike voltage testers, continuity testers are always used when a circuit is turned off or on wiring or devices that are disconnected from the circuit. They don't test for the presence of voltage but rather to see whether an electrical path is intact in an appliance or a device. For example, they are great for checking whether a single-pole switch or three-way switch is working properly or for testing whether a fuse is blown.

If you are using a continuity tester on a device attached to circuit wiring, always turn off the power to the circuit or device. Or disconnect the device from the circuit wiring. It can be dangerous to use a continuity tester on wiring that is carrying voltage.

Multimeter

• Best for: Measuring multiple electrical values

Multimeters are versatile electrical testers capable of many different testing functions. Most multimeters can provide precise readings of resistance, AC and DC voltage, continuity, capacitance, and frequency, offering virtually all the information offered by other types of electrical testers. 

Multimeters have a boxy body with a digital or analog readout, a dial for setting the test function (voltage and various readout settings), and two long leads with metal probes at their ends. These testers can range widely in quality and accuracy, and you'll often have to pay more for quality. They are generally more expensive than the basic testers but still not too pricey.

Solenoid Voltage Tester

• Best for: Measuring multiple electrical values

Solenoid voltage testers, known as "wiggles," are multifunction testers for voltage and polarity and are somewhat simpler to use than multimeters. Pros often prefer this tool over the multimeter, as it has no batteries to monitor. It isn't as accurate as a multimeter in providing a numerical measurement of the voltage present, but it is generally less expensive.

Both analog and digital models are available. Solenoid testers have two wires, each with a probe, extending out of the bottom of the tester. Voltage is marked by clicking or vibrating—the louder the clicking or more pronounced the vibration, the higher the voltage level.

During testing, they often trip ground-fault circuit-interrupter (GFCI) devices or GFCI circuit breakers, which is a "bonus" because they can test a GFCI device's functionality. Placing one probe in the hot slot of an outlet and the other probe in the ground instead of neutral will trip the GFCI device.

Digital Clamp Meter

• Best for: Measuring multiple electrical values

A digital clamp meter combines the function of a multimeter with a current sensor, and it's slightly more expensive than a multimeter. It's a specialty tool that few homeowners will need unless they are engaging in advanced electrical work.

There are subtle differences in function between a multimeter and a clamp meter. The most obvious one is that this tool features clamping jaws that can grip wire conductors. This makes the tool somewhat safer and easier to use in some applications, such as when working inside an open circuit breaker panel to test individual circuits. The tool also features wire leads that allow it to be used in the same manner as a standard multimeter. 

Wand Voltage Meter

• Best for: Detecting and measuring voltage

A wand voltage meter is another somewhat expensive specialty tester usually owned only by professional electricians. This numerical voltage tester has electrostatic wands that can detect and measure voltage simply by holding them in proximity to wires or metal contacts. For example, placing the wand near an NM cable will indicate the amount of voltage.