low current measurement of pico amps

Thread Starter

nvssaravanan

Joined Oct 4, 2010
1
HI all,

I want to measure insulation resistance in the range of pico amps.
i want to convert it to micro amps for mega ohmmeter indication.
the test voltage for the measurement is about 27V DC.
The mega ohmmeter working current is about 0 - 200mA.

Which IC i have to use for amplifying the current for the above measurement.
 

Adjuster

Joined Dec 26, 2010
2,148
HI all,

I want to measure insulation resistance in the range of pico amps.
i want to convert it to micro amps for mega ohmmeter indication.
the test voltage for the measurement is about 27V DC.
The mega ohmmeter working current is about 0 - 200mA.

Which IC i have to use for amplifying the current for the above measurement.
Have you made a mistake with that meter current? A 1MΩ resistance measured with 200mA test current would dissipate 40W.

To pass 200mA into 1MΩ, the test voltage would need to be 200kV!

Perhaps you have a meter which also measures much lower resistances, with a higher test current?
 
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