SYSTEM FOR ULTRASONICALLY DETECTING DEFECTS IN A PIPE WALL

摘要

System for detecting defects in a pipe wall (1), comprising ultrasonic transducer means (2) which are arranged for emitting, via an exit opening, ultrasonic signals from the interior of the pipe towards its wall and for receiving, via an entrance opening, backscattered signals from its wall. The transducer means are arranged to emit and receive a multitude of signals having their main directions within a plane (4) mainly perpendicular to the pipe axis. The diameter of said exit and/or entrance opening of the transducer means mainly has the magnitude of the wavelength of the used ultrasonic signals. The complex of emitted and backscattered signals are processed, in processing means (5), using a high resolution imaging process based on the transmission times of the emitted and backscattered signals. The transducer means may comprise a mainly circular array (3) of ultrasonic transducers, located in said plane or may comprise at least one ultrasonic transducer, and guiding means (6) arranged to provide the signals to be emitted and the backscattered pulses to be received in all directions within the perpendicular plane through the transducer means.