Capacitor testing

Discussion in 'General Electronics Chat' started by bwd111, Oct 7, 2013.

  1. bwd111

    Thread Starter Member

    Jul 24, 2013
    117
    1
    If I obtained zero reading with ohm meter would this indicate a good Capacitor? This is where I get confused! I was taught if zero reading then infinity that would mean a good cap. Then I read zero the infinity means good cap. Which is it
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,524
    2,369
    If zero is read and it stays at this then the capacitor is usually shorted, it should read infinity or may start off at a lower value and climb depending on the capacitance, if a significant value, you meter will show an opposite polarity when reversed and then drop.
    This is a crude test, however.
    Max.
     
  3. #12

    Expert

    Nov 30, 2010
    16,277
    6,788
    Besides that, capacitors usually won't get to infinite reading if they are large (over 100uf) and the meter is a very good meter. You usually settle for a few hundred megohms with large capacitors and call that, "good enough".

    Small capacitors can usually get to an infinite reading, and, crude as this method is, reversing the leads and thinking about the time it takes for the capacitor to charge on the scale you used for another capacitor just like it will give you a crude idea if the size is similar the the last one you measured. It depends on whether you are doing something very critical or just getting approximate readings.
     
Loading...