Analysis of the Outputs and Corrosion Rates of ACM Sensors in Aqueous Solutions with Different Salt Concentrations

Abstract

For analyzing corrosion rates in a wet environment, Fe/Ag galvanic couple atmospheric corrosion monitoring ACM-type corrosion sensors were immersed in aqueous solutions with different NaCl concentrations to measure their output currents and Fe-Ag potential differences. In addition, resistmetr y corrosion monitoring RCM sensors were used to determine the actual corrosion depths for comparison with the data collected from ACM sensors. The comparison revealed correlations between actual corrosion depths and output of ACM sensors, and potential differences between Fe and Ag showed higher correlations when compared with output currents of ACM sensors. Accordingly, it is considered that corrosion rates can be accurately estimated from conventional output current values under rainless environment, and from Fe-Ag potential differences under wet environment. Moreover, this method is thought to help to extend the life of ACM sensors.