Testing Faraday Cup for Electrostatic Charge Measurement

[Weiber]

Hello everyone. I am trying to use a Faraday cup constructed by myself to measure the electrostatic charge presence in particles of a fluidized bed reactor. I am trying to test if it works properly but I am having some problems.

I am tried to apply a voltage of 1.5 V till I obtain that voltage between the layers of the cup and then disconnecting it to see if it maintains that potential during some time, but when I disconnect the voltage source it looses the potential in like 2 seconds. Shouldn't it conserve the potential like a capacitor?

I have tried to measure the charge of particles connecting the faraday cup to a picoammeter, but when I collect the particles inside I obtain oscillations over and under the zero. Maybe it is not correctly constructed or I am testing it wrong.

Thank you so much for your attention. Regards!

 

[Christoffer B]

It would be useful to know how it's constructed, is it shielded against EM radiation? Could there be a high impedance leakage path between the plates (could be grease/dirt on standoffs etc.)

-Chris