Topic: condenser testing question especially for two tired

[octagon]

from a post by two tired, sounds like a great way to evaluate a condenser, but i don't quite understand how to set the test up. should the condenser be connected to the battery in parallel to the meter? if so why would the meter show any change when the condenser is disconnected? 

Here's a check using a voltmeter and a 12 V battery.  Affix your meter leads to the capacitor.  Place your condenser on the battery terminals, body to negative, other lead to positive.  The meter should read full battery potential.  However, when you remove the capacitor lead, the meter display slowly diminishes its reading.  My digital meter took about 10-15 seconds to get back to zero.  My analog meter did this in 1 second.  This test outcome will depend on the circuit loading effects of the meter.   But, if your digital shows a slow decay reading, the condenser is still behaving like a capacitor and probably serviceable.

[onepieceatatime]

should the condenser be connected to the battery in parallel to the meter? if so why would the meter show any change when the condenser is disconnected? 

That is what it sounds like he is describing. You are using the battery to charge the condenser to battery voltage and when the condenser is disconnected to the battery, the resistance of the meter will slowly discharge the condenser. The higher the resistance, the slower the discharge. A higher end meter will have a higher resistance resulting in a slower discharge rate.

[Bodi]

The condensor can be thought of as a battery. Not a great battery - but it "stores" electricity. Putting voltage on it charges it up. Remove the power source, and it starts to discharge. These particular condensors store very little power, and have a fairly high self-discharge rate, so the voltage will drop pretty quickly even with no connection.
The test charges it up using the battery, then you measure the discharge rate. A "bad" condensor, old and dried out or defective, will drop to zero volts almost instantly. A good one will take a while: TT's timing makes sense. Digital meters measure voltage indirectly and use very little power to do it. Analog meters have a tiny motor driving the meter needle against a spring and use more power, so the voltage drops faster. There's no exact time - different meters will give different times. If you can get a known good condensor you can test it with your meter and get a target time. Anything close (twice to half as long) should be just fine (these are pretty low tolerance condensors, +100/- 50% is ok).

[octagon]

that's great info guys. thank you, also thanks to two tired for the original post