円周Lamb波による自己干渉性を利用した減肉計測法
Accurate wall thickness measurement using autointerference of C ircumferential Lamb wave.
著者:
川野 亜久利 Aguri KAWANO 西野 秀郎 Hideo NISHINO
発刊日:
公開日:
Calibrating air-coupled sensorsCircumferential Lamb wavesNon Contact Air Coupled UTPipe wall thickness
概要
In this paper, a method of accurately measuring the pipe wall thickness by using noncontact air-coupled ultrasonic transducer (NAUT) was presented. In this method, accurate measurement of angular wave number (AWN) is a key technique because the AWN is changes minutely with the wall thickness. An autointerference of the circumferential (C- ) Lamb wave was used for accurate measurements of the AWN. Principle of the method was first explained. Modified method for measuring the wall thickness near a butt weld line was also proposed and its accuracy was evaluated within 6 .m error. It was also shown in the paper that wall thickness measurement was accurately carried out beyond the difference among the sensors by calibrating the frequency response of the sensors.
