Abstract
When assessing coatings for corrosion protective performance properties, conventional electrochemical impedance spectroscopy (EIS) and electrochemical noise measurements (ENM) are well established methods available in the laboratory. However, there remains a need in the protective coatings industry for techniques to evaluate the corrosion-protective properties of anti-corrosive coatings in-service. A portable electrochemical noise measuring device has recently been developed at the University of Northampton (UK) for this purpose. In this paper, this device has been used to evaluate electrochemical noise resistance characteristics on coated substrates during exposure in an accelerated test. These values have been compared with conventional ENM data, and with EIS results for the same coating systems. Overall, the information generated by the portable corrosion meter showed good correlation with the equivalent conventional EIS and ENM data obtained. Additionally a preliminary assessment using the portable ENM instrument has been made on a coated test sample exposed on an exterior exposure test rack for a period of 1-year, which demonstrates the potential utility of the portable electrochemical noise measurement method.