Circuit to detect picoamperes current

[neoaspilet11]

Guys,
I will gladly appreacite if anybody can give me ideas or circuit doagram for this application.

Thanks in advance

 

[IanP]

To detect such a low current you really need something special ..
Here are a couple of publications for your consideration:
https://www.intronics.com/products/pdf/310.pdf
www.keithley.com/data?asset=6198

LEAKAGE RESISTANCE
In working with picoamp signals and/or impedance values in the range from 107 to 1011 ohms, attention to insulation and guarding techniques is extremely important. For example, a leakage resistance of 10ra ohms from the 15 volt power supply
to the negative input of the 31O will cause a 150fA error current which is 15 times greater than the 10fA bias current guaranteed for this amplifier.

107 means 10 to the power of 7 ..
1011 --> ten to the power of 11 ..
Regards,
IanP

 

[wwfeda]

SMUs can measure really small current change. Keithly have some good ones. SMU = sense measuring unit.

You can force voltage and see the current being drawn on your circuit.