Digital techniques in laser generated ultrasound

Summary form only given. The authors have used three types of noncontacting receiver and evaluated their performance-capacitance transducers, electromagnetic acoustic transducers and laser interferometers. All have their advantages and can be readily interfaced to a digitisation system. The various digitisation techniques that they have used including Tektronix, LeCroy and Gould systems are discussed and a system that would be suitable to be used with an industrial version of this remote technique is defined. In addition they describe the various analytical facilities that are available with digitised data. The application of the laser technique to the study of delaminations in carbon fibre material and debonds in plasma sprayed material illustrates the display techniques that can be linked to a scanning laser system