On Tue, 21 Aug 2007 13:20:56 -0500, clifto wrote:

DaveC wrote:
I use Fluke meters in the field because they're pretty "bullet-proof" re.
their cases.

Not just the cases. My 77 got hit years ago when I got the test lead a
little too close to a flyback transformer. The size of the arc suggested
that I exceeded the maximum allowable voltage by one or two orders of
magnitude. The meter was unfazed, no change in calibration or looks.

I agree on Fluke robustness. Pretty much the same story with my 8520A
bench meter.

I wanted to make my own high voltage probe. At a flea market I had
aquired some glass encapsulated resistors that were multi-megohm. I
thought they would be perfect for my probe divider, so I built one in a
plastic tube. Tried it at some hundreds of volts and it seemed to be
working as expected. I applied it to something like 1700 V. The tube
was clear plastic, and to my horror the resistor lit up with plasma and
ugly clicking noises came out of the meter. Looking at the meter, the
fluke display had switched to Klingon or something. Expecting disaster,
I power cycled the Fluke. It came back to life and was fine.

That resistor still baffles me. As I said it was in a glass tube and was
at least an inch long. It looked perfect for HV. My guess is that it was
filled with some gas to deliberatly short itself at some voltage in the
low KV range.