SIZING AND CHARACTERIZATION OF ULTRASONIC INDICATIONS USING IMAGING TECHNIQUES

For discontinuity analysis more and more sophisticated methods are use d in the nuclear industry. The rapid development of computer technolog y offers the possibility to use imaging techniques. Instead of special ized focusing transducers the more flexible synthetic focusing techniq ues can be used. Presupposing that the material is ultrasonically isot ropic and homogeneous, imaging techniques make it possible to visualiz e the reflectivity of the volume to be tested. Siemens developed the h igh speed holographic instrument Holo 3000 in cooperation with the Uni versity of Bochum. In this paper the method of Broad Band Holography i s presented in the context of other imaging techniques. Different filt ering methods have been investigated in order to achieve highest resol ution and best signal to noise ratio with a given dataset. Different t ransducers respective wave modes have been applied to austenitic welds and claddings. The reconstructed image was evaluated using image proc essing techniques in order to investigate the possibilities to produce results easier to be quantifed than the original reconstruction. The results presented show a reliable expert tool for analysis measurement s which also can be used for flaw detection.