A Multiple Set-Point Polarization Technique for Electrochemical Corrosion Rate Measurement in Potable Water Distribution Systems

The electrochemical polarization of copper, black iron, and galvanized iron pipes was studied to evaluate methods of improving the accuracy of corrosion rate measurements made in plumbing systems. A cell configuration was chosen that uses pipe coupons as the working surface and simulates the conditions and flow characteristics of the distribution system. The cell can be used to estimate corrosion currents and to map variations in the corrosion potential across the pipe surface. Electrochemically measured corrosion rates correlate well with those measured by weight loss and vary as a function exposure duration and water quality conditions.