Active Microwave Thermography to Detect and Locate Water Ingress

This article reports on the application of a new and efficient nondestructive testing and evaluation (NDT&E) technique referred to as active microwave thermography (AMT) used to detect and locate water ingress within a structure. First, a mathematical formulation and analysis is established that relates the water extension and location to the temperature distribution over the inspection surface and enables evaluation of water from the measured temperature data. Following the analysis, the AMT measurement results of a small volume of water, placed in a rubber sample at a predetermined location, are reported. The results verify the analysis and demonstrate the potential of AMT for water detection. In addition, analysis of the measurement data indicates the potential of AMT for not only detection of water ingress but also accurate depth estimation of small amounts of water ingress.