Electrochemical Noise

The electrochemical noise method measures changes in the electric potential and current between freely corroding electrodes. Highly sensitive instrumentation is required as the fluctuations are on such a small scale. Three electrodes are needed to simultaneously measure both the potential and current noise. Different corrosion processes will produce different noise signatures. This data may be used to identify pit initiation and growth before visible detection. However, the interpretation of signals is complex, with different strategies developed to help interpret results. Although this method is proven and can detect different corrosion processes, there is skepticism over the accuracy of corrosion rates derived from the measurements.