Resistor Ohm Meter

[Gusse]

hello

I can measure up to 3 nenoamp and 6 uV.
event thats not problem.

I am not able to get linearity.

i.e., if ADC o/p 500mV for 1 teraohm.

then i am not getting 250 mV for 2teraohm.

Even i must use amplification of lower current(from Piko amp to Nenoamp)..

Now I'm a little bit puzzled.

Do you mean that you can measure:

1) 3 nano A (3 * 10^-9)

500V -> Rmax = 170G ohm

or
2) 3 pico A (3 * 10^-12)

500V -> Rmax = 170T ohm

Rmax is maximum resistance that you can measure.

When you try to measure 1T and 2T, how you know that insulator is exactly ~1T and ~2T? This linearity issue is also bit unclear.

BR,
-Gusse-