The development of an ultrasonic testing procedure using TOFD technique in the context of dead zones and spatial resolution

Abstract

The increase in the use of advanced ultrasonic testing techniques such as TOFD and Phased Array, observed in recent years is connected with the necessity of development of appropriate testing procedures, differing significantly from typical procedures for conventional ultrasound examinations. For this reason, the paper describes the most important issues that should be analyzed and taken into account at the stage of preparation of the ultrasonic examination procedure with the time of flight diffraction TOFD technic. Particular attention has been paid to the size of TOFD dead zones and changes in spatial resolution on the thickness of the joint tested, as well as the clarification of the principles for the assessment of unmeasurable in the direction of joint thickness indications.