reading with high impedance output (Keithley 2440)

Hi all,

I am using Keithley 2440 and I am going to charge a capacitor and then measure the voltage of that capacitor to see how fast it discharges BY ITSELF. So I need to set the output to High Impedance and measure the voltage.

But my problem is how I can measure while I set the output to High Impedance. I made a vi to do that. But during discharging, Keithley voltage remains the same as charging. So, obviously I am not using High Impedance correctly.

Is there any tutorial for measuring voltage and/or current at High Impedance output setting?

Thanks