Non-contact thickness measurement method for steel structures in liquids

摘要

PROBLEM TO BE SOLVED: To provide a non-contact type thickness measurement method of an in-liquid steel structure which can measure a wall thickness of the in-liquid steel structure without the necessity for expert knowledge even if an amount of deposits adhering to the in-liquid steel structure is large.SOLUTION: A non-contact type thickness measurement method of an in-liquid steel structure includes: an arrangement process for separately arranging an ultrasonic wave transducer 20 to a steel plate 10 being a measuring object in a non-contact state; a radiation process for radiating an ultrasonic wave to the steel plate 10 from the ultrasonic wave transducer 20; a wave receiving process for receiving a reflection wave which is reflected from the steel plate 10 by the ultrasonic wave transducer 20; a correlation processing process for extracting deposits 40 adhering to the steel plate 10, and a surface reflection wave from a surface of the steel plate 10 and a multiple reflection wave by correlation-processing the reflection wave which is received in the wave receiving process; and a calculation process for calculating a thickness of the steel plate 10 by measuring a time interval of the multiple reflection wave. In the arrangement process, a distance between the surface of the steel plate 10 and the ultrasonic wave transducer 20 is set shorter than a focus distance of the ultrasonic wave transducer 20.SELECTED DRAWING: Figure 7