Recent Advances in Non-stationary Thermal Non-destructive Characterization

Thermal wave imaging is one of the widely used non-destructive testing and evaluation (NDT&E) methods for detecting subsurface defects in most of the solids. Presently, three different active thermographic techniques are predominantly in use : Pulsed Thermography(PT), Lock-in Thermography(LT) and Pulsed Phase Thermography(PPT).To overcome some of the limitations of these widely used conventional thermographic techniques (requirement of high peak power and long experimentation time), present work focuses on recently proposed non-stationary thermal exci-tation technique for non destructive testing. This present paper highlights advantages and limitations of the prop-osed method by comparing with the conventional thermo-graphic methods.