Some testers are multifunction devices that can perform most, if not all, of the common electrical testing duties. Others are single-function devices that test for just one particular thing, such as live voltage. Below, we’ll break down the ins and outs of each common type of electrical tester to help you choose which is right for your project. The device is like a mini wand with a small tip on the end that senses voltage in such things as 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 as well as 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, though the measurement is not nearly as precise as that offered by certain other electrical testers. To use a neon voltage tester, simply 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 tip of the tool will light up if there is current 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 grounding slot, it means the outlet is not properly grounded. Plug-in circuit analyzers have three neon lights that light up 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 have no 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 tell you what the voltage is and circuit conditions on an LCD screen. This new type does require batteries or recharging. 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 something like 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. Multimeters have a boxy body with a digital or analog readout, a dial for setting the test function (as well as 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. Both analog and digital models are available. Solenoid testers have two wires, each with a probe, extending out of the bottom of the tester. They announce the presence of voltage by clicking or vibrating—the louder the clicking or more pronounced the vibration, the higher the voltage level. They often will trip ground-fault circuit-interrupter (GFCI) devices or GFCI circuit breakers during testing. This is a handy “bonus” in that it can be used to test the functionalist of a GFCI device. By placing one probe in the hot slot of an outlet and the other probe to ground instead of neutral, it will trip the GFCI device. 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. Be realistic about your skill and confidence levels with electrical work, as well. If you only have basic knowledge, you might be safer and better off not spending money on a tester with all the bells and whistles—consider hiring a professional electrician instead.
