DGS Deviations Using Angle Beam Probes

Abstract

Oversizing occurs using the DGS method with traditional angle beam probes. Most angle beam probes have rectangular transducers. In order to find an explanation of the deviations, the sound fields of straight beam probes with circular and rectangular transducers are analyzed and compared. Straight beam probes with circular transducers generate a rotationally symmetric sound field. Due to the effects at the interface between the probe wedge and the test piece, the generated sound field is far from rotationally symmetry-independent on whether a circular or a rectangular transducer is used in angle beam probes. Using the same DGS diagram for sizing with these different sound fields does not look promising. The observed issue of the deviations is not an issue from a single probe manufacturer, but a common problem with traditional angle beam probes.