I'm having some trouble with ceramic capacitors. looking for a little help...
I'm using a Tenma 72-8155 LCR meter to measure some ceramic caps I bought on ebay straight from china.
when I measure electrolytic caps I get a +/-5% steady reading
when I measure any of these ceramic caps it's all over the place.
I measure a 104 (100nF) and it will read a 47 to 51nF and bounces around a little while doing so
I measure a 22pF and it will give me anywhere from 30 to 40 pF
this is with all caps in each baggie.
is it the caps or the meter?

 

is it the caps or the meter?

Yes. (Sorry, couldn't help myself.)

The specs for your meter claim good accuracy down to 2nF, so the 22 pF readings might be expected to not be all that great. The 100nF accuracy should be good, though, and so I'd start to be very suspicious of those caps. Do you have any 'good' 0.1µF caps around?

 

I always suspect cheap Chinese junk from ebay.

 

Make sure you use short leads, 6 inch max. also make sure that you are not near any lights that have high frequency inverters that drive them. bench light and eco power flouro's are terrible for being picked up by sensitive meters.

 

wayneh. I was thinking about digging into the manual to see if I could find something like that mentioned there. Thanks for that. I do have a couple 22pF ceramics that I had purchased from Mouser and they read just about spot on.

recklessog. I tried the 6" gator leads and also the little sockets right on the meter. Same either way.

Thank You All,
John

 

some ceramic caps I bought on ebay straight from china

eBay + from China = counterfeit