Advantest TR8641 Electronic Picoammeter Manuals?

[lugaw]

Please help me find manual for this picoammeter.

[lugaw]

It seems to be a cousin of Keithley 414S picoammeter.

I need to figure out what the Fine and Current Compensator knobs do to the system.

[serg-el]

User manual TR6841

[Swainster]

The 'S' bit in the 414S refers to suppression, in particular, the ability to suppress or null out a large fraction (typically 2 decades worth) of the input current in order to look at tiny variations. For instance, you might want to show a 10uA F.S. variation on top of a constant 1mA bias current. It is basically like have a stable constant current source in series with the picoammeter.