Review of thermal imaging systems in composite defect detection

Thermal imaging technologies are widely used at present in many industrial areas, while being nowadays more and more employed in R&D&i activities. This article focuses on the comparison of the results obtained with commercially available non-experimental infrared (IR) cameras in the field of non-destructive defect detection. One of the cameras belongs to the FLIR SC5000 series, which is a medium wavelength infrared (MWIR) camera, and the other two cameras are from the high-end ImageIR series manufactured by InfraTec GmbH: The ImageIR 8300 also belongs to the class of MWIR cameras and the ImageIR 8800 is a long wavelength infrared (LWIR) camera.
The comparative study is carried out by means of inspecting three different calibrated and induced defect samples with these three cameras using similar excitation sources, so that the configuration and lay out of the tests are comparable with each other. Additionally, after every inspection, a mathematical post-processing is applied to the resulting raw thermal images in order to enhance the detection of defects present in the samples.