Is an ESR Meter the best measure for caps?

Yes, that is capacitance. You can measure it with most multimeters.

Antti OH7GLS

I haven't owned a multimeter yet that will measure capacitance--what do you mean?

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Most common digital multimeters above $30 will measure capacitance, it's not a space program design...

Antti OH7GLS

The Sencore LC103 that we use makes four measurements, capacitance, ESR, dielectric absorbtion, and dc leakage. I have found many bad caps with the DA test that tested good on ESR, capacitance, and leakage. High DA caps will usually leak but sometimes can produce very unusual symptoms.

Still, nearly all of the bad caps I find are caught with ESR tests on my DSE kit or the capacitance measure on my Fluke 179. Hard to beat the Bob Parker design for value. The Sencore is nice for the bench but not very portable.

Leonard

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Actually, it does come from a space program design :-) (Like all microelectronic parts)

Also dielectric absorption (rare, but can cause problems in some circuits) and leakage.

Tom

The ESR meter measures the electrical source resistance. This is very important. This is In fact the reactive resistive efficiency, if you want to look at it that way.

The capacitance measurement, is another important test. A cap can measure to have the proper capacitance, but its ESR can be out of specs. If this is the case, the cap will fail when under the stress of use.

ESR is equivalent series resistance. It's mostly an issue with electrolytic capacitors. These have a wet electrolyte that can boil out via high temperatures or just dry up over time. For these types of capacitors, high ESR is a significant failure mode!

I know of no good way to measure it but RMS current rating might also be significant.

Nice instrument (or test system, rather) The price in the USD 2500 range(!!!) is prohibitive for individuals and small firms. I use a handheld LCR meter, made in the far East (our is marked Escort ELC131D) It measures R, L and C, but as it uses 60Hz and 1kHz it isn't suited for ESR measurement. I use a home-built ESR meter which really is an ohmmeter using a 50kHz signal. The multimeters I have seen have just limited C and L ranges.

Stein

Thanks for making that correction about what ESR stands for and what its significance is, Mr Schuler. ;) If you didn't, I was going to!

Regards, Bob

"Charles Schuler" wrote:

I did purchase the dick smith ESR meter and am very happy with its performance--I was just curious if there was another aspect to a caps properties that could be more telling as to its expected performance

thanks for the great replies!

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Without doubt, an ESR meter gives the very best indication of an electrolytic's servicability. I have had many year's professional experience of tracking capacitor faults, and on many occasions, I have had caps whose ESR is out of the window, but whose value read on a capacitance meter, is almost spot on. Thus, using a capacitance meter, the bad cap would not have shown.

Another major advantage of the ESR meter over other tests, is that the check can be carried out whilst the component is still in circuit. Only other check I ever carry out, is with a simple analogue ohm meter - actually an AVO 8. The reason for this is that an electrolytic in good condition, may have an indicated ESR of say 0.08 ohms. However, this apparently very good reading, could also be a DC short circuit of 0.08 ohms, internal to the cap ...

Hope this helps

Geoff

experience

have

Was the B&K Model 801 Capacitor Analyst the first to measure ESR?

Larry Dishman has told me that the Creative ESR meter dates back to the early-mid 1980s. If it wasn't the first ESR meter on the market, it was one of the first. And after all this time, it still has a very dedicated band of supporters.

Bob

"NSM" wrote:

I see they still go for $25 and up on eBay. Somehow I trust this stuff more than a bunch of little CPU's!

Rupturing electrolytics: The excerpt below is from:

The document cites an article published in September 2002 by Passive Component Industry Magazine, saying that some PCs were failing because of faulty low ESR capacitors. The problem, according to that article, was due to imperfect water based electrolytes built in China by Lumious Town Electric, and subsequently the people who built that part marketed it to aluminium manufacturers in Taiwan "including Luxon Electronics Corp, Lelon Electronics Corp and many others".

Such caps were unstable after packaging, leading to a build up of hydrogen causing either the case to rupture, or the seal to be breached, and causing electrolyte fluid to leak onto motherboards.

I've used both. I own the DSE digital. Some caps need to have a very low ESR and the analog display is useless. You can use a digital ESR meter to look for shorts, as well.

You only need one "CPU" to do a simple function like that. Plus some nice analog transistors and stuff to help it do its thing. :)