Employing electrochemical frequency modulation for pitting corrosion

By using the electrochemical frequency modulation (EFM) technique, the non-linear behavior of a corroding system is measured. This non-linear behavior is likely to be different for a system undergoing uniform or pitting corrosion. The implementation of the EFM technique to detect pitting corrosion has been investigated by observing the fluctuations in the so-called causality factors. These causality factors, resulting from an EFM test and in the ideal case having values of 2 and 3, respectively, are normally used for quality and data validation purposes. While investigating pitting corrosion, they show different behavior leading to the CPT (critical pitting temperature) detection.