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Ok this is my first post so apologies if this is inappropriate but I need some solid opinions from guys who know about house earthing

So me and my dad just moved into an old house and I was walking around with my multimeter in NCV setting and it starts beeping when I hold the meter up in the air.

Now I'm not talking a stray beep every now and then like a false reading, this thing beeps continuously until I bring it back down close to my body and immediately beeps again when I raise it up, I'm familiar with inductance and body capacitance and all that but this is spooky

  • It beeps when I put it close to the kitchen bench (which has a metal strip along the perimeter), as soon as I touch the metal it stops beeping

  • It beeps near his ACOUSTIC guitar strings which is sitting on a stand and stops once I touch the strings

  • It beeps near any metal plate such as a small metal poster or piece of metal rod I have laying around and again, stops once I touch them

  • It beeps near some of the door hinges too

Is my house not grounded properly or something because both our phones act weird and slow in the kitchen and in some spots around the house

Now I'm an electrical engineer so please don't tell me I'm using my meter wrong or that it's broken because it beeps everywhere it's supposed to (near mains plugs, lights, appliances) but I've never seen the NCV go this crazy around random things and I'm worried the house may need some attention

Thank you to anyone who reads this and chips in, all advice is appreciated.

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    \$\begingroup\$ If you're an EE then check the earth impedance. If you're an EE then any doubt about safety should have you calling an electrician if you can't do this test yourself. So, I'm questioning your thought process here rather than telling you the use your meter correctly. There is a difference. \$\endgroup\$
    – Andy aka
    Nov 18, 2020 at 12:27
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    \$\begingroup\$ If we are not allowed to tell you you’re using your meter wrong or your meter is broken, maybe you could make it clear what we ARE allowed to tell you? \$\endgroup\$
    – StarCat
    Nov 18, 2020 at 12:27
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    \$\begingroup\$ Well, if you are in training, how do you respond when you are told that what you are doing might be wrong? Do you start every tutorial or lesson that you attend by telling the lecturer or trainer that you might be a tad sensitive to criticism? \$\endgroup\$
    – Andy aka
    Nov 18, 2020 at 12:58
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    \$\begingroup\$ Everyone is in training, we all have our areas of expertise and electrician work isn't mine. Forgot how rude you lot can be, I'm asking if my house has an earth leak. \$\endgroup\$
    – DeeJayger
    Nov 18, 2020 at 13:03
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    \$\begingroup\$ Thank you for your time lads, I quickly checked the AC voltage from mains earth to my bench before I left for work and it gave me 7 volts AC, not sure if that's negligible or not. I'm not near a power station but there's a decent sized transformer out front of my next door neighbors house up on the power lines, but the UHF/VHF idea could be promising, unfortunately I don't have a digital field strength meter, would a simple radio be of any use to help detect whoever is making all this noise? \$\endgroup\$
    – DeeJayger
    Nov 18, 2020 at 22:35

1 Answer 1

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It's probable that the 'non-contact voltage tester' is responding to a strong RF field, with the metal objects acting as 'retro reflectors'.

The sizes of those objects point to a VHF / UHF transmitter nearby.

It would most certainly not be a grounding issue since the metal beading of a bench, guitar strings, a metal rod and a metal hinge would not be even remotely connected to anything electrical.

The presence of a strong RF field, and its frequency, may be confirmed using a digital field strength meter.

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