It clearly arced inside. It looked like a neon tube not a simple arc-over. The voltage I was measuring should not have come anywhere close to arcing across that length. That's why I'm thinking it was designed to do that. I looked for the resistors yesterday to see if I could find markings, but I can't find where I stashed them now.
Low impedance would be a burden, not high.
Damn... the TerrellTard got one right.
Fact is, mere "coffee breath" can cause them to fail.
A bath in hot IPA (microwave a cup full to boil point), and a new flux brush will do a VERY good job.
If it is a single arc event, it won't always cause it to fail completely. The arc has to sustain long enough to form carbon arc trails.
Try a Simpson 360.
Always loved 'em. A friend has one. I finally persuaded him to keep it in the house and buy a cheapo DVM for garage use. It's not that the 360 couldn't take it, but he's already run it over with a car once and scratched the case.
I recommend one of these:
Dave.
It may have been a precision high impedance feedback resistor for the type of instrumentation amplifiers used on Faraday collectors and other scientific instruments to measure minute currents. They are normally only ever used at very modest voltages and are optimised for lowest possible noise in that application.
Typically they are in the 10^7 to 10^9 range - their manufacture was (is?) a black art.
Regards, Martin Brown
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