Calibration of EIS analyzers using reference impedances

Inhalt:
The electrochemical impedance spectroscopy (EIS) is used to estimate the state of charge and the state of health of batteries made from lithiumion cells. A calibration traceable to SI units of such instruments is up to now possible only to a very limited extend. However, such calibration is essential in order to ensure comparable measurement results for a reliable battery diagnosis. To meet this demand, a prototype of a reference impedance was realized using electronic components. Also a calibration procedure has been developed, that can be carried out using only the standard equipment of a calibration laboratory for AC quantities.