Application of Ultrasonic Phased-array Techniques for Inservice Inspection

This paper gives a brief overview of modern ultrasonic inservice inspection techniques using a phased-array system. Experimental results on the application of the system in the nuclear field are discussed, especially the measurements carried out on geometries which are complicated in relation to the ultrasonic inspection. These are, for instance, the spherical bottom or dome of nuclear pressure vessels or the inner nozzle radius. In order to solve this inspection problem it must be considered also that there is a very reduced accessibility for the ultrasonic probes. Further, the principle of the data acquisition and evaluation is described.