What is the name of the ultrasonic testing technique where the transducer is positioned at an angle to the test surface?

The technique referred to is Angle Beam Testing, which involves positioning the ultrasonic transducer at an angle to the test surface rather than perpendicular to it. This angled approach allows for the evaluation of welds and detecting flaws that might lie beneath the surface or at specific interfaces, such as those found in thicker materials or intricate geometries.

In Angle Beam Testing, the refraction of sound waves at the angle of incidence is used to create a path that maximizes sensitivity to certain types of discontinuities. The technique is particularly effective for inspecting the quality of welds since it can create a shear wave through the material, improving detection capabilities for flaws like cracks and voids, which may not be easily identified using normal beam techniques.

This method is essential in many industries where structural integrity is critical, enabling inspectors to assess safety without causing any damage to the components being tested.