Ultrasonic non-destructive testing head - reduces side lobes in flat polygonal piezoelectric converter having diagonal in sound incident plane

摘要

The test head uses ultrasonic frequency. It has facilities for reducing the side lobes of the ultrasonic signal. It consists of a flat polygonal piezoelectric transducer which transmits the ultrasonic signal into the material being investigated. The effect of the side lobe is reduced by arranging the transducer such that one of the diagonals of the device is approximately in the incident plane of the sound. The transducer is preferably mounted on a wedge. The transducer shape can be rectangular with any relationship between the sides. It is turned through a given angle between the main oscillation axis and incident plane. The wedge may be rotatable. The transducer surface may have parallelogram or rhomboidal shape. Two such transducers may be used for testing apparatus with separate transmission and receiver arrangement.