Methods and arrangement for the determination of crack-depths in ultrasonic non destructive testing

摘要

A method of determining depth propagation of a defect in a body by ultrasonic materials testing wherein a first angle probe having an ultrasonic wave transmitting oscillator produces a scatter signal at structural inhomogeneities of a body formed with a defect and the scatter signal is received by an ultrasonic wave receiving oscillator of a second angle probe, which includes: transmitting an ultrasonic wave at a first angle along a first line in direction towards the defect so that the scatter signal thereat is shadowed by the defect and diminished in intensity; receiving the diminished signal from the defect at a second angle in a direction along a second line intersecting with the first line at a defect, transmitting additional ultrasonic waves and receiving diminished scatter signals along respective lines intersecting at the defect at varying depths of the body and ascertaining the depth propagation of the defect by a marked increase in intensity of the received signal when the intersection of the respective lines along which the ultrasonic wave is transmitted and the scatter signal is received reach beyond the innermost limit of the defect.