1
$\begingroup$

I bought a Digital EMF Tester Electric and Magnetic Field Radiation Detector here.

At first, I thought it was a metal detector since keyboards (without being inserted into a USB port) cause alarm, however even wooden doors seem to set it off. My bed mattress has not.

What is causing such high readings of 128 V/m? I put it onto a wooden table 30cm away from the nearest cable (my laptop charger) and my arm, yet as soon as my arm touches the table it gets that high reading and alarms.

Improve this question
$\endgroup$
3
  • 2
    $\begingroup$ That's not a high number at all. If you think that's making you sick, keep in mind that the static electric field of the Earth itself, without any man-made technology around, is often several times higher! You'd have to live in an empty, bare metal cage to escape such fields. $\endgroup$
    – knzhou
    Commented Aug 1, 2023 at 0:44
  • $\begingroup$ Do you have a ballpark estimate for what would be a concern? $\endgroup$
    – securityauditor
    Commented Aug 1, 2023 at 0:50
  • 1
    $\begingroup$ Well, if you go outside during a thunderstorm you might be sitting in a field of order $10^4 \, \mathrm{V}/\mathrm{m}$, and that's okay. And a Van de Graaff generator can make fields of millions of volts per meter, presumably enough to blow out your detector, yet small children regularly touch them in science museums without any ill effects. $\endgroup$
    – knzhou
    Commented Aug 1, 2023 at 1:17

0

Reset to default

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.