Ultrasonic echography process and device

摘要

For determining zones in a piece (such as cracks) which reflect ultrasounds, an apparatus is provided which comprises a transducer for transmitting a fine ultrasound beam and for receiving ultrasound echo signals. That transducer is moved externally of the piece for scanning it and the coordinates of each zone which returns an echo signal higher than a predetermined threshold in response to an ultrasound pulse are determined. The transducer is moved according to a composite movement which results from the composition of a conical movement about an axis which is orthogonal to a surface of said piece having an apex on the surface and a rectilinear movement parallel to the surface. Consequently, the beam enters the piece after path of constant length out of the piece. Each zone of the piece to be examined receives the beam under a plurality of different azimuth angles and the echo signals returned from a same zone of the piece are combined. An isometric view of the locations of the echoes in the piece is displayed.