LABORATORY COMPARISON OF COUPLED MULTIELECTRODE ARRAY SENSORS WITH ELECTROCHEMICAL NOISE SENSORS FOR REAL-TIME CORROSION MONITORING

摘要

The performance of the electrochemical noise sensors made of carbon steel and stainless steels were tested and compared with the coupled multielectrode array sensors made of the same materials as real-time corrosion sensors. No correlation was observed between the pit index signals for localized corrosion from the electrochemical noise sensors and the corrosivity of the solution. The noise resistance signals for general corrosion that were averaged over long time intervals appeared to correlate with the corrosivity of the solutions. However, the fluctuation of noise resistance signals was significant and often overwhelmed the measured signals. Averaging over long time intervals were required to obtain meaningful noise resistance signals for the electrochemical noise (EN) sensors. Thus the EN sensors may not be reliable for real-time measurement of localized corrosion. It may be used for real-time measurement of general corrosion. The responses of the coupled multielectrode array sensors to the localized corrosivity of the solutions were excellent.