Corrosion signal processing using wavelet analysis and Nyquist diagrams

Electrochemical noise (EN) analysis is a technique that can be used for monitoring corrosion processes. It is often used to obtain information relating to the rate of corrosion by use of the noise resistance and spectral noise impedance calculations. This paper demonstrates two signal processing techniques that can be applied to EN data. An example of a continuous wavelet transform of EN data obtained from a non-stationary system is given. Impedance information is extracted from wavelet transform data and compared with impedance measurements using an independent technique. The complex noise impedance, a novel EN analysis technique developed to compliment the spectral noise impedance, is also described.