Measuring Very Low Currents - Picoammeter Adapter (Louder audio)

** Re-uploaded with louder audio **
I built the picoammeter adapter designed by "Gyro" on the EEVBlog forum.
The video describes how it works, it's construction, and a basic test.
It seems to work quite well, though I'm having problems with noise at the output levels of just a few millivolts (which is probably caused by the way I've done things).

Links to the EEVBlog forum threads:-

[briansauk]

Nice build and demo - two quick thoughts. First one is simple - set your voltmeter to average 10 or more readings - you should be able to get another "reliable" digit that way. Second is more complicated, but typical for electrometer grade instruments - use a triax cable where you set the inner shield to same potential as the inner conductor. Your circuit will need to be quite a bit more complicated, but that is what it typically takes. This is by no means criticizing your work - just thoughts for how to take it further.

[ivolol]

At those sorts of amplifications you're probably reading the noise floor of the opamp and thermal noise of the resistor. Not to mention turning absolutely every other electrical appliance off or just going outside with it might also improve noise.