Ghost Voltage Article

Hey Guys,

Thought maybe you might find this interesting.

When IBM swapped out our Triplett and the “Jap Meter”, (a hardened analog meter we got pretty cheap) with the Fluke 8060 we had the same problem. Some folks went as far as to make up an adapter that put a megohm across the leads. That is enough to damp out the phantom voltage. The rule that will get you by is to only measure voltage directly across the load. If you have a lamp or virtually any appliance plugged in and turned on you can trust the voltage across that load. Where you get in trouble is with unterminated conductors that are floating at both ends. They make a digital meter a random number generator. I am still not sure why they don’t have an internal load resistor that can be put across the leads. That would really only affect guys who are probing CMOS anyway, even it it was there all the time. If I was a regular sparky I would just solder a megohm in there past the selector switch so it was only affecting the voltage scales.
The adpters were made with piggyback banana plugs and the resistor between them.