New toy arrived. In new old stock condition
This is Voltmeter/Picoammeter.
With lowest metrologically significant current 10^-15A and resolution 10^-16A.
As voltmeter this unit can measure voltages from 10uV to 200V with input impedance is greater than 10^14.
This unit is 30year old, and demanded replacement of electrolytic capacitors, which was done. I'm replaced old capacitors with new Epcos B41858 and B41859 series.
Some techporn, input commutator with sapphire insulators: