Impedance based coating degradation, wetness, and cumulative damage sensors were
deployed in several US Marine Corps bases. The sensors were placed inside dehumidified
storage buildings and on ground vehicles stored outdoors to monitor the performance of
corrosion preventive compounds (CPCs), and the severity of the environment as a function of
time. The sensors were able to record coating integrity information real-time, and transmit this
information remotely from a set of readers and base stations to a web-based portal for
convenient monitoring and analysis. The sensor data were in agreement with visual
observation of the sensor surface. The sensor information indicated vast differences in
corrosivity depending on location, environment/seasonal conditions, storage location and
location on vehicle. The least severe condition monitored was the dehumidified storage in
Camp Lejeune, where the assets were protected from precipitation and condensation, and the
relative humidity levels did not exceed 60%. The most severe conditions were found on
vehicles stored on-lot, where coatings applied to boldly exposed surfaces were completely
degraded and exposed elements were severely corroded. The CPCs were, however, effective
in case of crevices, even under the most severe environmental conditions. In this paper, the
results of the 2-year program are summarized.
Keywords: condition based maintenance, corrosion preventive compounds, wireless sensors