| 摘要 |
PROBLEM TO BE SOLVED: To provide a method enabling efficient reduced-thickness inspection over the total length of piping regardless of the length of piping by controlling an electromagnetic ultrasonic wave transmitted from an electromagnetic ultrasonic wave transmitter to be directed in just one direction on the axis direction. SOLUTION: Transmitters 1A, 1B are arranged at positions shifted only a distance L1 of a phase angle of 90 degrees on the axis direction of the piping. The transmitter 1A transmits an electromagnetic ultrasonic wave with a phase angle zero degree (zero cross point) as the start point of a transmission control as shown in Fig.6 (a), and the transmitter 1B transmits an electromagnetic ultrasonic wave with a phase angle of 90 degrees (peak point) delayed 90 degrees from the transmitter 1A as the start point of a transmission control as shown in Fig.6 (b). Thus, these super imposed waves are as shown in Fig.6 (c) and transmission is provided on only the R side of the transmitter 1A. COPYRIGHT: (C)2011,JPO&INPIT
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