New technique of defect sizing of a small inclined crack on a free surface using multi-tip-waves

Experiments using a full digital flaw detector from which several tip echoes were obtained with the main echo for reflections by an artificially inclined small crack on a free surface are described. The crack height is 1.5 mm, and inclination angles are 10 to 40°. Incident waves of 45° are given from both sides of the crack. Crack height and inclination angles are estimated from the distances of from the distances between two echoes. The results show good agreement with actual values. It is shown that automatic inspection will be possible using this method