ULTRASCHALLECHOSYSTEM

摘要

The system contains a transducer arrangement (1) of a number of concentrically arranged annular piezoelectric ultrasonic transducers (2, 3) as transmitting/receiving device. To transmit a pulse-shaped ultrasonic wave, only the outermost ring (2) of the transducer arrangement is used whilst all of its rings are effective for receiving the echo signals. All the rings are connected to the signal evaluating device (6) via variable delay lines (5), the delay value of which decreases quadratically from the centre towards the edge of the transducer arrangement. This system has a high lateral resolution and a great depth of focus and an increased detection sensitivity. <IMAGE>