We have been attempting to use the EVAL-AD5941 board with SensorPal to collect data using EAB sensors in PBS using SWV and evaluate its performance when compared to data collected using a Gamry potentiostat.
The setup described online ( https://wiki.analog.com/resources/eval/user-guides/eval-ad5940/software_examples/ad5940_swv ) is being used for the placement of JP9, 10, and 11. However the data that is collected is very different from the Gamry. I understand that SensorPal outputs the raw current/voltage data and it needs to be processed to plot the current difference, but this data is not similar to the raw Gamry data either.
Impedance has also been tested with the board set to the dummy sensor of resistance 6.8kOhms and the data is close to this value so I assume the board is functional.
When the usb cable is attached to the board but nothing is not connected to the usb cable, the data is also inconsistent even at the same current range. However, this usually occurs beyond the selected final voltage since data is collected far past the value of -100mV. I am unsure if this is an issue with the board or the SensorPal program.
The settings used for the SWV are as follows:
- Initial Voltage: -400mV (sometimes changed to -600mV)
- Final Voltage: -100 mV
- Step Potential: 1 mV
- Frequency: 300 Hz
- Amplitude: 25 mV
- Current Range: We are testing what best works for our application
- Other parameters are kept at default settings
From the data collected using the Gamry we assume a current difference of less than 5uA and less than +/-3 uA for the forward and reverse current. The Gamry is also using a current range of 0.3mA when set to choose the range automatically but this value does not seem to work for the evaluation board.
This is a graph of the data taken while using an EAB sensor although I am unsure if the sensor was fully functional, partially functional, or damaged at the time of using it.
Overall, I am unsure as to whether the issue is the setup of the board jumper pins, the parameters being used, or if the board is not functional. Additionally, is there any reliable method of ensuring that SWV is working on the evaluation board and what current range should be used? The voltage exceeding the final voltage set is also an issue since this seems to be damaging the EAB sensor, making it nonfunctional.