| 摘要 |
In the present invention, an inspection hole (17) is formed at the longitudinal-direction lateral surface of a boiler water tube (10a), the base side of a guide pipe (16) is connected to the inspection hole (17), and a closing member (24) is continuously attached to the guide pipe (16). When the thickness of the boiler water tube (10a) is measured, the closing member (24) is detached from the guide pipe (16), an ultrasound probe (18) is inserted from the tip side of the guide pipe (16) into the boiler water tube (10a), and the ultrasound probe (18) is caused to move within the boiler water tube (10a). |
