Impedance analyzer help

[KD8CGH]

I'm a new Discovery 2 user that's trying to measure impedance. I running Waveforms 3.10.9 Windows 10 64 bit. I made a simple circuit with a 2k R as DUT

W1 C1   2k R   C2   1k R   GND

and ran a 1k  compensation shorting W1, C1 and C2 to one side of the 1k R and GND to the other side and open with all unconnected. Doing a low frequency sweep from 1 kHz to 10 kHz I see results like Rs: 29.9 k   Xs: -46.8 k   theta: -57 at 2 kHz.

Any ideas why this is so far off?

[attila]

Hi @KD8CGH

Both compensations should be done having the reference resistor connected.

The open compensation should be done without the DUT:
W1-C1 <open> C2-R-GND
The short compensation should be done with the DUT place shorted: 
W1-C1 <short> C2-R-GND

 

[KD8CGH]

Thanks Atilla

  I recalibrated and now it behaves better. I also got an Analog Discovery Impedance Analyzer board which is working as expected too.

        Bob