A Microprocessor Based Isopotential Contouring System for Monitoring Surface Corrosion

Abstract A microprocessor controlled scanning reference electrode system has been developed to produce isopotential contour maps of corroding surfaces. Using Ag/AgCl microelectrodes, reproducible and easily interpreted results were obtained for the corrosion of mild steel in dilute aqueous chloride solutions. The contours recorded were closely correlated with observed corroding areas, and in uninhibited solutions, the development of corrosion pits could be followed. The effectiveness of corrosion inhibitors in reducing the potential difference around pitting areas was readily apparent, with chromate inhibitors being superior to phosphonate inhibitors.