I bought this tool and am waiting for delivery.
This is a very rare device. According to my calculations, only about 600-1000 of these devices were produced. And it's great luck that I was able to find this device. Even if not complete.
I may be wrong, but I think this is the most sensitive instrument on Earth that can be put on a table. And which does not require vacuum, low temperatures and other things for operation.
Datasheet says, that this instrument can measure 1E-17A, with resolution 1E-18. Tests show that this device is really capable of measuring currents 1E-18A, and have sensitivity in 3E-19A...1E-19A range.
This instrument have first production date is 1986 year. Design of this instrument was carried out by MNIPI (Minsk Research Institute of Instrument Construction).
Before this instrument MNIPI also have other old instrument that can measure 1E-17A: V7-29, that have start production in 1972 year.
Some information about architecture of this instrument.
The current measurement in this instrument is based on current integration. Amplifier in current integrator is chopper stabilized.
All other info: restoration, photo, tests and others is coming soon. After delivery this instrument.
Historical:
This device became possible thanks to the work of such a person as Konstantin Sergeevich Shuklin. The electrometric unit and DRK-6 were developed by him. The appearance of the DRK-6 was preceded by almost 30 years of work.
The chief designer of this device is Glubokiy Iosif Andreevich.