Wavelet Analysis of Electrochemical Noise Data

In this study, localized corrosion (pitting) was induced on identical electrodes of ASTM A516 steel in an electrochemical cell to produce electrochemical noise (EN) data. These EN data were examined then using wavelet analysis (WA) to determine if WA could be used to identify clearly the presence of pitting corrosion and its onset. It was found that, under pitting corrosion conditions, there was no high-frequency energy contribution seen, but there was an energy contribution of the low-frequency crystals. Additionally, visual time domain examination of the crystals produced by WA shows the individual contributions made by each frequency range toward events in the original signal. This allows for the identification of the onset and termination of pitting corrosion in this system.