Infrared radiation emitted due to scanning of a hot spot as a probe of hidden defects

Specially created subsurface defects in a sample are detected using a high resolution infrared camera FLIR SC7000. A scanning hot air (about 110 °C) nozzle is applied to introduce additional energy in a researched sample. The hidden defect has an increased temperature in comparison with the surrounding area that is a result of changed emissivity and thermal diffusivity. The suggested method is compared with pulse thermography which uses a xenon lamp for excitation.