Multimeter sensing AC current at front of meter - what else could make it "sense"?

Discussion in 'General Electronics Chat' started by RogueRose, Oct 10, 2016.

  1. RogueRose

    Thread Starter Member

    Oct 10, 2014
    I have a SouthWire 10040N multimeter that has an autosensing AC circuit that lights a light at the front of the meter when it detects AC. I'm wondering why it lights up when it passes some people (arms, leg, hand, torso, etc) and others it doesn't. The light doesn't stay on like when I press it to an AC outlet, but it flashes on and off as I pass it across some people's bodies - while other people it doesn't...

    I can press the meter to the battery pack of a drill and press the trigger and it won't light. It will sometimes flash when pressed to the motor of the drill when on.

    I'm just more curious about the sensing on human bodies and why it doesn't do it on some people. Do we have robots among us? :)

    Operating Manual

    Spec Sheet
  2. atferrari

    AAC Fanatic!

    Jan 6, 2004
    What if you repeat the test with the same "lot" of positives and negatives in further sessions?
    RogueRose likes this.
  3. tranzz4md


    Apr 10, 2015
    It's an active device, using some sort of capacitive coupling/sensing. At least that's what I believe causes it in some "squeakers" or non-contact detectors made to warn of energized electrical wiring or devices. Move it very quickly over nearly any surface and you'll get something.
    RogueRose likes this.
  4. GopherT

    AAC Fanatic!

    Nov 23, 2012
    Check if they are wearing "electrically insulating" vs "static disipating" shoes.
    RogueRose likes this.
  5. BR-549

    Well-Known Member

    Sep 22, 2013
    "NOTE: The detector is designed with
    high sensitivity. Static electricity or other
    sources of energy may randomly trip the
    sensor. This is normal operation.
    NOTE: The non-contact voltage detector simply detects the presence of voltage -
    it will not measure and display the voltage on the LCD screen"
    RogueRose likes this.