Arrangement for testing thick-walled specimens by the ultrasonic pulse- echo method

摘要

In an ultrasonic pulse-echo test arrangement which is particularly suited for testing heavy-walled workpieces, a plurality of transducer probes are used. Two or more transmitting transducer probes are arranged so that each probe transmits its sound beam to a respective test zone, the zones being staggered relative to each other across the thickness of the workpiece. A defect in a respective zone reflects energy to a predetermined location at the rear wall of the workpiece, such location being common to all defect responsive reflected signals. A receiving transducer probe is disposed for receiving all of the defect responsive signals reflected from the stated location. Electrical circuit means cause the defect responsive signals generated in the receiving circuit to be of the same amplitude irrespective of location in the workpiece if the defects are of equal magnitude and cause, furthermore, the transmitted and received energy to be compensated for individual variations in the coupling quality between the respective probe and workpiece surface.