| 摘要 |
PROBLEM TO BE SOLVED: To provide a thinning ratio estimation method that uses a guide wave to realize accurate estimation of thinning ratio of a thinned wall part generated in a pipe.SOLUTION: A thinning ratio estimation method includes the steps of: causing guide waves to enter a surface of a testing member provided with a thinned wall part from a probe 11 at n incident angles &bgr;(i is an integer from 1 to n), respectively; using the probe to receive echoes resulting from reflection of the guide waves at the thinned wall part; obtaining a maximum echo intensity value A(α) with respect to each of refracting angles αcorresponding to each of the incident angles &bgr;; obtaining an echo center α, which is a representative of the refracting angles, from the refracting angles αand the maximum echo intensity value; creating a master curve showing a relationship between the echo center αand a thinning ratio of the thinned wall part; causing the guide waves to enter a pipe to be measured, and obtaining an echo center γ on the basis of the echoes obtained through the reflection of the guide waves; and obtaining the thinning ratio corresponding to the echo center γ of the pipe to be measured from the master curve. |
