2018 年 3 巻 p. 167-172
The infrared thermographic test has the advantages of safety, efficiency, and ease of use. However, the test is often subjected to environmental influences, which sometimes causes false detection of flaws. Background reflection from sunlight or neighboring structures is one of the major factors contributing to this issue. In most cases, the background reflection results in a higher temperature, which is recognized as a flaw indication. In this study, the authors apply a polarization theory to address the problem and propose a quantitative separation method of background reflection and flaw indication. As the first step of the study, the polarized emissivity and the polarized reflectivity were quantitatively evaluated. Based on these results, a quantitative extraction program for detection of flaws has been proposed.
