Acoustical fields from rectangular ultrasonic transducers for non-destructive testing and medical diagnosis

Abstract

Theoretical results are given for pressure and intensity in the acoustical field produced by rectangular ultrasonic transducers. Comparison between the fields of square, circular and rectangular transducers is made showing that the field of a rectangular transducer, by comparison with that produced by square and circular transducers, may be divided into three zones rather than two: the very nearfield, the nearfield and the farfield. Some experimental results are shown confirming the general shape of the predicted curves. Emphasis is put on the difficulty of interpreting quantitative ultrasonic results with rectangular probes.