Been buying lots of old film caps to sell on Fleabay and have come across some that I'd like to test for leakage. I don't have a fancy cap checker so I've been clipping them into a small SE amp in parallel with the Sozos in there. The Sozos show about 10 - 15mv by themselves and when clipping in one of the old caps, I read around 20mv consistently, having tested around ten of them.
My question is what is the cutoff point for acceptable leakage in film caps?
DK
Minimum Acceptable Cap Leakage
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VacuumVoodoo
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Re: Minimum Acceptable Cap Leakage
Minimum acceptable leakage is 0 nA.
Maximum acceptable leakge for dry film non electrolytic capacitors is much lower than what a budget DMM can measure reliably.
We measure leakage in nA and uA or mA for electrolytics.
20mV means nothing in this context unless you know the resistance across which this voltage is measured and internal resistance of your voltmeter. Knowing these parameters you should be able to calculate current and assess whether the result is reasonably acceptable.
Maximum acceptable leakge for dry film non electrolytic capacitors is much lower than what a budget DMM can measure reliably.
We measure leakage in nA and uA or mA for electrolytics.
20mV means nothing in this context unless you know the resistance across which this voltage is measured and internal resistance of your voltmeter. Knowing these parameters you should be able to calculate current and assess whether the result is reasonably acceptable.
Aleksander Niemand
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Life's a party but you get invited only once...
affiliation:TUBEWONDER AMPS
Zagray!-review
Re: Minimum Acceptable Cap Leakage
Okay, so I guess my findings were moot? In that case I'll be heading over to my buddy's place where he has one of those fancy cap testers.
Re: Minimum Acceptable Cap Leakage
The point being that 'is the 20mV developed across eg 1M or 10k?'
Very different leakage currents.
Pete
Very different leakage currents.
Pete
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