How to test a capacitor with an ESR meter ? Esr meter just shows a number (certain Ohms value ) but how to decide whether the Cap is good based upon that number? is there a range for good capacitors ???
Some ESR meters have a table of suggested values printed on the front panel - or in the user manual.How to test a capacitor with an ESR meter ? Esr meter just shows a number (certain Ohms value ) but how to decide whether the Cap is good based upon that number? is there a range for good capacitors ???
AFAIK; temperature stability is also an indicator of whether an ESR value is normal or faulty.I was wondering about this exact question a few years back when I first built myself an ESR meter. More recently I replaced all the electrolytics on a power supply board, and the rule-of-thumb I learned in that project was that any electrolytic showing more than 5Ω is suspect. I bought new caps from 1µF to 150µF, and not one of the new caps in that range showed more than 5Ω of ESR. Some of the caps I replaced showed 40Ω. They had no visible damage and still had rated capacity, but were clearly failing.
Measuring against specifications requires expensive test equipment, but field measurement with a cheap meter can give useful diagnostic information.
by Aaron Carman
by Jake Hertz
by Jake Hertz
by Jake Hertz