Ultrasonic scanner using four crystal element for reactor vessel - injects longitudinal acoustic waves to given depth at specific incident angle

摘要

The ultrasonic or electro-acoustic scanner consists of four crystal elements (1). It is used for ultrasonically scanning thick-walled metallic workpieces such as pressure vessels. The housing of the scanner is in contact with the surface and is moved along a given pattern. The scanner uses longitudinal sound waves at a depth of 5-20 mm. The crystals are arranged at a given angle to the sub-surface. The sound waves are passed through a wedge-shaped plastic (3) so that they are deflected to impinge on the metallic surface at a given angle.