piezo-electric sensor optimizes multi-element

The present invention relates to an ultrasonic transducer (1) is intended for ultrasonic inspection of a weld zone, said transducer comprises a plurality of transmitter elements / receiver (3) of ultrasonic waves for transmitting ultrasonic waves direction of the weld zone and to receive ultrasonic waves reflected from the weld area, the transmitter / receiver elements (3) ultrasonic waves are arranged so as to obtain an ultrasonic transducer with a sensing surface formed by at least two sets of transmitter elements / receivers of ultrasonic waves which extend in at least two different directions (X, Y), each set of transmitter elements / receiver (3) of ultrasonic waves comprises at least one alignment element transmitters / receivers of ultrasonic waves, it is characterized in that at least one transmitter / receiver of ultrasonic waves is disposed inter section of the two directions. The position of a transmitter element / receiver center is at the intersection of the two directions makes it possible, in the case of a spot weld, detecting the presence of a shrinkage in the center of the welded point.