On Wed, 16 Feb 2005 19:07:02 GMT, "NSM" wrote:


wrote in message
oups.com...
I recently bought a Sencore LC102 off of e-bay. It was calibrated just
prior to sale. When checking caps for ESR, I only get readings on
electrolytics, no other type caps. Other caps cause the meter to flash
a high value, regardless of control/voltage settings. The meter will
read value though for all caps. Am I doing something wrong, or is my
meter gimped? Thanks.

Surely it's telling you the caps are good. Try adding a 10 M ohm resistor in
parallel with a small cap and see what it says.

That will not tell him anything useful. ESR is important only when it
gets over an ohm or two (depending upon cap value and voltage rating).

If you are measuring small value capacitors (1 ufd or less) the ESR
meter will not be accurate as the the ESR of the cap will be swamped
out by its capacitive impedance.

Remember that the ESR meter uses a high frequency test signal so that
the capacitive impedance is insignificant with respect to the
equivalent series resistance of the capacitor. When the capacitive
impedance gets large (small cap value) the meter cannot tell the
difference between that and the ESR.

John