EIS (electrochemical impedance spectroscopy) is well established as a work horse in the laboratory evaluation of organic coatings performance. This paper describes the first step in the development of a test protocol to apply a field-portable ECN (electrochemical noise) sensor / system to the assessment of in-service coatings. The correlation between EIS and ECN scans on long-term lab coating samples confmns that ECN has the ability to discriminate, clearly, between "Good", and "Poor" coatings
p e r f o r c e . This may prove useful in extending laboratory EIS data on coatings to field evaluations of in-service coatings. EIS and a modified ECN technique were used to examine the protective properties of nine epoxy-paint coating samples. All coatings were on metallic substrates, and had been immersed in ASTM-D1141 synthetic seawater and had EIS data for periods ranging from two to ten years. Each tested-sample represented a different stage of coating aging and degradation, from "Good" to "Failed", with the differences between all coatings discemable using EIS. The observed resolution in noise current measurements, by the modified ECN method, encourages its application to assessing in-service coating conditions, by comparing ECN readings on field samples to EIS values measured on laboratory data base samples of the service coatings.