Dear community,
I'm currently working on a setup for testing the accuracy of an impedance sensor. The sensor should be able to measure impedances in the range of 5kOhm-1MOhm. My testing setup consists of resistors and analog switches which are able to change the impedance between the two measurement pins from 5kOhm to 1MOhm with an increment of 5kOhm. The analog switches are controlled by an Arduino Leonardo.
Using a resistor with a fixed value the sensor measures it accurately. The testing setup controlled by the arduino works as well. I can set the resistance using the arduino and I'm able to measure the same value using a multimeter.
But super strange results appear using the sensor to measure the resistance of my testing setup. The only difference between measuring with the multimeter instead of the sensor is that the multimeter uses DC voltage instead of AC voltage. This seems to be a big problem for whatever reason and I have absolutely no idea why this is the case.
I attached the schematic of the circuit and the mesuring results (plot of the relative error between the impedance measured by the sensor and the impedance set by the arduino).
I'm very thankful for all kinds of help. Thank you!
Best regards
Jannis
I'm currently working on a setup for testing the accuracy of an impedance sensor. The sensor should be able to measure impedances in the range of 5kOhm-1MOhm. My testing setup consists of resistors and analog switches which are able to change the impedance between the two measurement pins from 5kOhm to 1MOhm with an increment of 5kOhm. The analog switches are controlled by an Arduino Leonardo.
Using a resistor with a fixed value the sensor measures it accurately. The testing setup controlled by the arduino works as well. I can set the resistance using the arduino and I'm able to measure the same value using a multimeter.
But super strange results appear using the sensor to measure the resistance of my testing setup. The only difference between measuring with the multimeter instead of the sensor is that the multimeter uses DC voltage instead of AC voltage. This seems to be a big problem for whatever reason and I have absolutely no idea why this is the case.
I attached the schematic of the circuit and the mesuring results (plot of the relative error between the impedance measured by the sensor and the impedance set by the arduino).
I'm very thankful for all kinds of help. Thank you!
Best regards
Jannis
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