Electrical Testers Chart
Show side-scrollable chart for smaller screens.
| TESTER | GOOD FOR | LIMITATIONS | HOW TO USE |
|---|---|---|---|
| Electrostatic wand =volt stick =noncontact voltage tester |
Indicates presence of hot without direct contact | Not reliable close to earth, can't distinguish within bundle of wires, sensitive to a range of volts and to inconsequential induced voltage | Hold wand near wire or cable at different angles till light or indicator stays on |
| Simplest neon tester Video |
Hot presence pinpointed, relative brightness for different voltages | Good reading doesn't mean load will run | Touch one prong to hot, the other to yourself or something grounded |
| Three-prong receptacle tester
Video |
Quick, usually reliable for hot presence and (if there is a ground) neutral presence; some can also test GFIs | Depends on ground or neutral presence to work, descriptions can mislead, good reading doesn't always mean load will run, does not tell positively that hotness is absent | Plug into three-hole receptacle, read about resulting lights from list |
| Voltmeter | Volt presence and level | Good reading doesn't mean load will run | Touch one prong to each thing to tell voltage difference between them |
| Ohmmeter | Continuity and resistance level | Does not tell what resistance is under load (e.g., light bulbs, motors) | With circuit off, touch one prong to each thing for resistance between them |
| Clamping ammeter | Checks overloads and shorts in progress, whether something is running | -- | Clamp around single wire, not whole cable |
| Electromagnetic circuit finder =current tracer | Can pinpoint which breaker controls a live circuit. | Occasionally inaccurate; only expensive ones can trace wires in walls and underground | Transmitter plugs into receptacle; receiver indicates breaker at panel |
| "Wiggins" =solenoid voltage tester | Some ac and dc voltage levels, checks circuit operation under load, presence of good ground, can roughly test GFI | Does not tell positively whether hotness is present | Touch one prong to each thing to tell voltage difference between them |
|
Light bulb in socket with two wire leads Video |
Checks 120-volt circuit operation under load, presence of good ground, can roughly test GFI | Does not tell positively whether hotness is present | Touch one wire to hot, one to neutral or ground |
| Mechanic's Stethoscope | Hears arcing location | -- | Touch to nearby non-metal or grounded part; listen |
| Continuity tester | Tells general continuity | Cannot distinguish between a short and many normal connected loads | With circuit off, touch one prong to each thing for continuity (or not) between them |
| Multimeter | Combines voltmeter and ohmmeter | -- | see ohmmeter and voltmeter |
| Also see Which and How | |||