A Portable Impedance Spectroscopy Measurement Method Through Adaptive Reference Resistance

In impedance spectroscopy measurement with traditional voltammetry, the measurement accuracy will be varied due to the measured impedance, which is changed with frequencies and does not match the reference resistor. This paper proposes a portable impedance spectroscopy measurement method that the reference resistor match measured impedance rapidly and adaptively. The appropriate reference resistor is selected by the output-input amplitude ratio determination algorithm. The symmetric measurement circuit is designed to reduce the impact of electromagnetic interference, especially in high impedance measurements. Both theoretical and experimental analyses show the effectiveness of this method, the RMSEs of relative errors of the measurement results are under 2.5%, and the equivalent circuit parameters of the measured impedance can be accurately fitted.