Electrical Impedance Spectroscopy

Electrochemical impedance spectroscopy (EIS), like LPR, uses the polarization of electrodes to measure corrosion rates. The difference is that EIS uses alternating currents and measures the resulting phase shift relative to the applied current. The applied frequency is about 0.1 Hz to 100 kHz with more than one frequency required to obtain useful data. Typically, two frequencies are used; however, full frequency measurements may be used, producing the best data to identify the corrosion processes taking place.