[R-390] Black beauties

Kenneth G. Gordon [email protected]
Sun, 16 Mar 2003 22:30:40 -0800


> I have a Cap tester on this ExTech multimeter I just purchased.
> It seems to be accurate.  The problem I have is just how reliable is
> the meter checking.
> 
> 
> 
> Kenneth A. Crips W7ITC, Cheyenne, Wyoming

Multi-meter cap testers don't have high enough voltage to really 
check leakage in caps. They can do a decent job of measuring 
capacitance only.

You would need a Sprague Tel-Ohm-Mike, or Heathkit C-3 or IP-28 
, or equivalent, type of capacitor checker to measure leakage. You 
have to check the caps at their rated voltage in order to get an 
accurate idea of leakage.

One way you can check them for leakage without the above listed 
capacitor checker is to connect them in series with a decent 
milliameter across a source of HV at the rated voltage of your 
capacitor. If the milliameter reads much above a microamp or two, 
the capacitor is leaky.

Ken Gordon W7EKB