Information About Non-Contact Volt Meters

Information About Non-Contact Volt Meters

A non-contact voltmeter can help you quickly check for the presence of live wiring without touching bare metal. While a standard voltmeter can give you a precise measurement of voltage in a circuit, you must touch the meter's probe to the circuit to do it. A non-contact meter will signal you if a wire has voltage in it greater than a certain level, but it will not give an exact reading.

How to Use Non-Contact Volt Meters?


    • 1

      Plug a table lamp into an electrical outlet, and turn it on.

    • 2

      Turn the voltmeter on. If the voltmeter is a multifuction meter, turn its non-contact voltmeter mode on. Hold it to within 1 inch of the lamp's electrical cord. The voltmeter should give a clear indication of the presence of voltage. It may flash a light, make a beeping sound or both. If it does not, check the meter's battery and replace it if necessary. Try the test again.

    • 3

    • Turn the lamp off. Move the meter back and forth over the lamp cord. It should still give a voltage reading, since the lamp is plugged in.

    • 4

      Unplug the lamp. Hold the meter near the lamp cord. It should not indicate a voltage.

    • 5

      Hold the meter next to the outlet. It should indicate a voltage.

Tips & Warnings

  • Some non-contact voltmeters are sensitive enough to detect voltages as low as 24 volts. This is handy for tracing low-voltage wiring such as doorbell circuits (Reference 2, page 17).
  • Metal conduit, shielding, outlet boxes and panels will interfere with the meter's ability to detect a voltage.
20th Jan 2015

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