Non-stationary thermal wave imaging for nondestructive testing and evaluation

Abstract

Among various widely used Infrared Thermal Non-destructive Testing (IRTNDT) modalities, non-stationary thermal wave imaging (NSTWI) methods have proved to be an indispensable approach for the inspection and evaluation of various materials. Growing concerns of surface and subsurface defect detection capabilities with moderate peak power heat sources than the widely used conventional pulse based thermographic methods and in a reasonably less testing time compared to sinusoidal modulated lock-in thermography, make these NSTWI techniques invaluable for this field. The present work highlights a comparative study on various NSTWI techniques, further experimental results are presented to find their defect detection capabilities by taking signal to noise ratio (SNR) into consideration.