A novel data processing algorithm in thermal property measurement and defect detection by using one-sided active infrared thermography

The proposed algorithm is based on the analysis of an artificial front-surface pixel-based function which includes temperature and time. This function experiences certain extremums, and the corresponding times can be used for determining thermal diffusivity by the formula similar to the known Parker expression. In thermal NDT, such approach being applied to defect areas, provides diffusivity variations which can be used for the evaluation of defect severity in a particular specimen. In this study, both the theoretical basis and the some experimental implementations of the proposed data processing algorithm have been explored to illustrate its validity in thermal properties measurement and thermal NDT, including thermal tomography.