CRACK DEVELOPMENT MONITORING METHOD AND ITS DEVICE BY ULTRASONIC TOFD METHOD

摘要

PROBLEM TO BE SOLVED: To provide a crack development monitoring method by ultrasonic TOFD (Time of Flight Diffraction) method and its device for accurately measuring a crack depth while an installation is operated and automatically monitoring the development of the crack. SOLUTION: Data on the change of propagation velocity of ultrasonic longitudinal wave with temperature in a specimen 1 are previously stored in a data storage means 5. When a data processing means 7 calculates a crack depth in the specimen 1 from measured data by the TOFD method, the propagation velocity of ultrasonic longitudinal wave corresponding to the temperature of the specimen 1 in measuring is acquired for use from the data on the change stored in the storage means 5. COPYRIGHT: (C)2006,JPO&NCIPI