| 摘要 |
PROBLEM TO BE SOLVED: To perform thickness measurement and flaw detection accurately even in a curved or inner diameter changing portion of a tube such as a heat exchanger tube for a boiler. SOLUTION: A center member 101 of an inspecting head 100 is coupled to aligning mechanisms 150, 160 having aligning brushes 153, 163 and is positioned at the center of an interior space of a tube 1. A contact block 107 is connected via a universal joint mechanism 106 to the tip of an arm 102 rotatably mounted to the center member 101, and is pressed against an inner wall of the tube 1. An ultrasonic wave emitted from a built-in ultrasonic probe 108 in the contact block 107 is made incident on the inner wall of the tube 1 through water as a transmission medium fed into a recessed space 107b of the contact block 107. Since a contact surface 107a of the contact block 107 is continuously pressed against the inner wall of the tube 1 even in a curved or inner diameter changing portion thereof, the ultrasonic wave is made incident on the tube inner wall at a constant incident angle, so that thickness measurement and flaw detection can accurately be performed. |
