Ultrasonic characterization of defects

The method of acoustic holographic evaluation of defects was compared with conventional ultrasonic estimation by comparing results in determining the size of natural defects in thick section welds by both methods and also comparing these results with the actual sizes obtained by destructive testing. The dimensions of two defects studied were determined more accurately by the acoustical holographic method than by ultrasonic testing. In addition, measurements made holographically at two frequencies were in much better agreement than were measurements made at different frequencies by the conventional ultrasonic technique.