Collection of Electrochemical Impedance and Noise Data for Polymer-Coated Steel from Remote Test Sites

Degradation of 13 polymer coating systems on steel exposed to natural (NS) and artificial seawater (AS) was monitored using electrochemical impedance spectroscopy (EIS) and electrochemical noise analysis (ENA). Marine test sites were Port Hueneme, California, and Key West, Florida. An approach was developed to obtain electrochemical impedance and noise data from test sites via modem from the laboratory. A multiplexer was used to collect data at the test sites for the different systems. Impedance data were collected once a week, while noise data were measured twice a week. Potential and current noise data were determined simultaneously. Representative data from exposure to NS and AS for 7 months are presented for four coating systems. The long-term objective of this project is to determine the impact of microorganisms on degradation of protective properties of polymer coatings on steel during exposure to NS.