The durability test result in high temperature of EMAT for pipe wall thinning monitoring

This study checks the high-temperature durability of the electromagnetic acoustic transducer (EMAT) for pipe wall thinning. We inserted EMAT into the oven and measured the 10 mm thickness specimen by EMAT about two years. Measurement was carried out by two kinds, a pulse echo method and a pulse echo resonance method. And high-temperature durability was checked by both of the measuring methods. Compared with the pulse echo method, the pulse echo resonance method of measurement accuracy was better. The filter processing of removing magnet signal is required high-temperature measurement. EMAT is a simple configuration of a coil and a magnetic combination. Therefore, a sensor does not break early. Therefore, EMAT is applicable to the pipe wall thinning monitoring of a nuclear power plant. (author)