Abstract
Nondestructive inspection of a high temperature structure is required to guarantee the safety of it. However, there are not any useful sensors for high temperature structure. Some of them can' t work at high temperature over 50°C. Another one is too expensive to use it. The sensing system which can transmits and receives an ultrasonic wave which travel long distance by using a long wave guide has been studied. We could confirm that a guided ultrasonic wave can travel more than 500mm for using a thin bar with 2mm-diameter as a wave guide. However, we are having a difficulty to transmit and receive an ultrasonic wave from a test specimen. We are trying to improve the trial inspection system by using an ultrasonic horn.
