I was wondering: if you remove a capacitor from a circuit, you test its ESR and it seems fine for its stated capacitance, does it mean the capacitor is fine? Would an additional capacitance test be relevant? I'm asking this because I'm already using an ESR meter, my multimeter doesn't test capacitors, and I was wondering if an additional capacitance meter/multimeter would be worth the investment for hobby repairs. Does the ESR test (out of circuit) make the capacitance test obsolete? Sorry if it's a stupid question, I'm a beginner.
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Last edited by cib3k; 11-04-2013, 03:30 PM. -
Re: Is testing ESR enough?
And just to be clear: I know that ESR and capacitance are different things, and that ESR can be measured in circuit.
Also, another question: why do most multimeters that measure capacitance only go as high as 20uF-200uF? I've seen 2200uF electrolytics in PSUs and 3300uF on motherboards, so higher capacitances are pretty common. Is there a problem with accuracy, maybe?Last edited by cib3k; 11-04-2013, 05:04 PM. -
Re: Is testing ESR enough?
Hmmmm ... according to Fluke's DMM Selector Guide, almost all of their current DMMs that can measure capacitance can measure up to 10,000uF (just one is limited to 9,999uF), and some up to 100,000uF. Some of Extech's DMMs in the EX500 series are limited to 100uF, but some go up to 10,000uF; their EX400 series are limited to 100uF; their EX330 is limited to 200uF; their EX230 to 100uF; their MM500 and MP500 series are limited to 9,999uF; their MG300 series DMM-insulation testers are limited to 40,000uF. Agilent's U123X, U124X and U127X DMMs are limited to 10,000uF; Agilent's U125X DMMs are limited to 100,000uF. I realize Fluke and Agilent are pricey (don't go buying a Fluke 287 or an Agilent U1253 unless you really need that quality and capability level!); Extech's better DMMs are better in that respect without being cheap crap, though a little less capable.Originally posted by cib3k View PostPeteS in CA
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Re: Is testing ESR enough?
Multimeter s perform capacitance measurements at very low test frequency of few Hz.
Therefore they are worthless for Very low ESR capacitors which require 1KHz or higher as test frequency so to be calculated all parameters as Q / ESR / Capacitance.
In conclusion anything less than a complete LCR bridge is a toy.Comment
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