Effect of Top Layer Coatings on Active Microwave Thermography

Active microwave thermography (AMT) is an active thermographic technique that utilizes an electromagnetic-based excitation with infrared measurement of the surface thermal profile of a specimen under test. AMT has been successful utilized in the aerospace and civil infrastructure industries. This work seeks to expand AMT through the investigation of how coatings effect the technique. Results indicate that, dependent on the structure, the thermal contrast can experience different trends, such as linear or logarithmic, when under AMT inspection. This is important as it relates to any AMT investigation that involves a structure that has a coating.