can measuring power from an electric fence kill your voltmeter?

I think I may have killed my digital multimeter by trying to test the voltage pulses from my electric fence.  The fence was powered by a small charger, a Zareba .05 joule pulsing model, but soon after testing the voltage, I started getting extremely low readings on anything I tested, from a car battery to wall current.  Clearly it didn't blow the fuses in my meter (an Ideal 61-360) since they still registered power inputs, but just as clearly, something is very wrong with the meter now.  Any clue as to what might have happened?

verence2 years ago

Yep, sounds like your DMM is toast. The impulse on the fence is very high in voltage but only for a very short time. So the total energy is very low (it's normally battery powered - and should not kill animals or people)

Fuses need some energy to be triggered (the thin wire has to literally melt). The impulses do not have enough energy for that. In good DMMs there are other protection devices (varistors, spark gaps ...). If those devices are not present or did not work, the high voltage can kill semiconductors immediatelly.

tomasaur (author) 2 years ago

Sigh. That's what I thought was going on, but I wasn't sure about how it happened internally.

kjsrocks2 years ago

Well you fried it. I hope you aren't too attached to it.

You could salvage parts. There is a few nice switches inside that thing.

Digital multimeters (DMMs) get fried sometimes. That is part of the reason why I like inexpensive DMMs, because there's less heartbreak when I eventually do something stupid that fries the meter.

I dunno. Feeding high voltage pulses into a DMM seems to me like a good way to kill it.