3 electrode EIS measurement using AD5940 EVAL ELCZ

Hi,

The switch settings may be

.DswitchSel = SWD_CE0,
.PswitchSel = SWP_RE0;
.NswitchSel = SWN_AIN1|SWN_SE0;
.TswitchSel = SWT_AIN1|SWT_AFE3LOAD;

Thank you Akila
The switch settings worked
Do you know how to set VBias and VZero separately ?
I was able to change BiasVolt values but i couldn't find a way to change Vbias and Vzero. 

Thank you Akila
The switch settings worked
Do you know how to set VBias and VZero separately ?
I was able to change BiasVolt values but i couldn't find a way to change Vbias and Vzero. 

Hi,

Vzero is set by 

AppIMPCfg.Vzero 

Hi,

AppIMPCfg.Vzero  does not exist in Impedance.c and AD5940_Impedance project 

Could you please check into this?

Hi,

Can you search for AppIMPCfg.Vzero in Impedance.c

Hi ,

I did 

Hi,

I could find it here:

Hi,

I think we both have 2 different version of Impedance.c . The one i have was downloaded from AD5940_example github.. Could you share your version ?

Hi,

I am referring to 

ad5940-examples/Impedance.c at master · analogdevicesinc/ad5940-examples · GitHub

Hi,

Thank you for that link.

For our experiment we have to measure RzMag and RzPhase for a 3 electrode system

Problem : The phase values must be in the range of 0 to -90 degrees , but the phase values were going shooting up and down going out of bounds.

What can we do to get phase values within the range?

I have added the settings we used below

The outputs obtained from AD5940 EVAL ELCZ are

The Nyquist plot for the above table 

The Expected Nyquist Plot (Obtained from electrochemical Workstation)

Hi,

The swing may be due to saturation.

You may do two measurements:

1) One with HSTIARTIA_200

 2) Another with HSTIARTIA_40K

and check if you get expected readings with any one.

Hi Akila,
The above settings didn't work for me.
I decided to measure impedance magnitude and phase values of a resistor and capacitor in parallel.
Impedance magnitude value matched with theoretical value but phase values did not match.

Top View of RC Parallel connection

The above measurements were done in SensorPal 

Could you tell me how to get phase values correct ?