Projected thermal diffusivity analysis for thermographic nondestructive inspections

Conventional thermographic processing techniques use raw temperature signal as input data and produce an output signal whose features depend on the technique, with higher SNR improving the detection of existing defects. This paper proposes an innovative method developed from a 3D heat diffusion model by projecting the system to a coordinate plane which provides diffusivity values as improved output data. The results produced by this projected diffusivity method show a direct visualisation of the actual contour of defects producing an improvement in the SNR level higher than 15% with respect to the levels obtained by the conventional processing techniques.