Characterization of wet conductive coatings using eddy current techniques

A solution is required to monitor the spraying and drying process of wet conductive coatings and respective film thickness and conductivity. The method presented is an Eddy Current based solution that could enable a fast and precise characterization of the conductive coating thickness during the drying process of the wet coatings when the conductivity is marginal and highly variable. One challenge of this application is the shifting of apparent conductivity of the coatings during the drying process resulting in property variations due to changes in the coating morphology, thickness and volume. A further challenge is the application of Eddy Current sensors to wet surfaces without contacting the wet film, therefore requiring constant lift-off to avoid contaminating the coil sensor.