Quote:
Originally Posted by randomkiller
Phantom voltage is the only thing I dont like with the digital, I see it all the time with control wires in the same conduit or ducts with 480/277. If it shows over 80 I ll pull out the old Ideal solenoid to see for sure.
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It has nothing to do with being digital. They just happen to be that way for a reason other than being digital.
The input impedance on most DMMs are 10Mohm, so the slightest capacitive coupling would cause it to register a significant voltage. There's an adapter that brings down a DMMs input impedance comparable to that of a good 'ol Simpson meter, while still retaining CAT IV safety. It goes in between the leads and the meter and the part # is SV225. The adapter is basically a glorified 3,000 ohm parallel resistor built to 1kV CATIII and 600V CATIV specs.
If you're getting new meters, the rather basic Fluke 114,116 and 117 has a Lo-impedance mode integrated without the use of an external adapter. It's too bad this isn't available on the 87-5.
A solenoid meter is fine under ordinary conditions, but if you end up measuring a 480v line and there happens to be transients causing an internal arcover, that thing's going to turn into a bomb when the source has a short circuit current capacity in tens of thousands. If I'm checking on things in a home, I don't really care, but I would sure like to have a CAT IV rating if I was poking around things near that 1MVA 480V transformer.
Fluke has an article called ABCs of DMM safety if safety things sparks your interest at all.