Ultrasonic measurement method and apparatus of the surface crack depth.

摘要

PROBLEM TO BE SOLVED: To provide an ultrasonic measuring method and a device for a surface crack depth, capable of accurately measuring the surface crack depth even if the depth of the crack opened in a member surface is a fine crack having a depth of less than 1 mm.;SOLUTION: An ultrasonic measuring method for a surface crack depth comprises the steps of: applying a contact medium 11 on the surface of an object 6 to be inspected and filling the inside of the surface cruck 1 with the contact medium; scanning an oblique angle probe 10 along a scan line 10 set in a width direction of the surface crack 1; transmitting an ultrasonic wave 4 via the contact medium 11 into the object 6 to be inspected and the surface crack 1; receiving a reflection wave 15 thereof; dividing the reflection wave 15 into a surface echo 15a reflected by the surface of the object 6 to be inspected and an echo in medium 15b coming from the lower end of the surface crack 1 in the contact medium 11; and calculating a depth d of the surface crack 1 form the surface echo 15a and the echo in medium 15b.;COPYRIGHT: (C)2013,JPO&INPIT