measuring small capacities around 1 pF

Physikfan, Sun Oct 25 2020, 08:43PM

To all electronics freaks

Please, does anyone have experience with measuring small capacities
around 1 pF?
I'm just trying to measure the self-capacitance of an electrostatic
voltmeter, but so far with no real success.

regards
Physikfan
Re: measuring small capacities around 1 pF
Sulaiman, Thu Oct 29 2020, 02:30AM

If you have equipment to work at radio frequencies then you can measure the change in frequency of a resonant circuit when the electrometer is connected.
Re: measuring small capacities around 1 pF
Physikfan, Sun Nov 01 2020, 01:29PM

I want to determine the capacitance values of these electrometers:

IMG 6533
IMG 6721
IMG 6719
Re: measuring small capacities around 1 pF
Physikfan, Tue Nov 17 2020, 07:35PM

After the measurement with the HP4277 did not work out,
I would like to measure the internal capacities of these electrometers with this LCR meter:

HP4263B
Re: measuring small capacities around 1 pF
Physikfan, Wed Dec 02 2020, 04:33PM

For the two small electrostatic voltmeters I could
measure now finally the self-capacitances at 100 kHz,
taking into account the capacities
due to the geometry of the measuring cables:

Trüb and Täuber, Zurich, 0 - 500 V
HP 4277A: 7.1 pF
HP 4263B: 6.2 pF

GB instrument, 0-300 V.
HP 4277A: 10.5 pF
HP 4263B: 10.0 pF

Within the experimental error there is a good agreement of the values of these two different LCR instruments.
The way is now free for the measurement of the
insulation resistances due to observing the decrease of a short time applied voltage as a function of time.