Measuring leakage current

[andy257]

Hi All,

I am trying to measure very small leakage currents in the nA range and would like to know if anyone has any ideas on how best to go about doing this.

The problem i have is i am using serval pieces of kit which all use different types of connectors. I have a VI source meter that uses 4mm sockets, a switch matrix that uses BNC and a Electrometer that uses a Triax connector.

I have attached a diagram of the setup i am using. The idea is to use the Source meter to supply the HV voltage and connect the Electrometer to measure the leakage current. However when meauring in the nA range i encounter all sorts of problems which i am not sure if it is an acurrate measurment or problems are occuring through jigging wiring etc.

If anyone can see any suggestions i can make to perhaps gain a more accurate measurment that would be super.

ALSO: The return path for the signal is through the shielded enclosure because i am using BNC and the outer shield of the BNC is in direct contact to the enclusure. Can you see any safet hazards doing it this way?


Thanks

Andy