Defect detection method for metal tubes through electromagnetic wave propagation characteristics analysis

Metallic tubes used in power plants and industrial plants may develop cracks and change in shape owing to external factors and long-term usage. To prevent accidents caused by such defects in the metallic tubes, various non destructive inspection (NDI) methods have been established. However, these conventional methods require a considerable amount of detection time and effort to inspect the long tubes. To avoid this problem, we propose a method using propagation characteristics of electromagnetic waves. In the previous paper, we proposed the new NDI method by using the electromagnetic wave. However, it was necessary to use "a reflected wave from the normal metallic tube without any defect" as a reference. In this paper, we propose an original method for obtaining precision in defect detection without the requirement of "a reflected wave from the normal metallic tube without any defect". By using this original precisions method, we can realize more versatile detection methods. © 2017 The Institute of Electrical Engineers of Japan.