What is the aim of performing a straight beam examination prior to angle beam examination?

Performing a straight beam examination prior to conducting an angle beam examination primarily serves the purpose of ensuring that the weld is free from visible flaws. In ultrasonic testing, a straight beam examination is typically conducted as an initial inspection technique to assess the surface and subsurface conditions of the material being evaluated. By detecting any visible surface flaws, such as cracks or inclusions, this step helps to establish a baseline condition and determines whether the weld quality is adequate for further, more complex inspections using angle beam methods.

The straight beam technique allows inspectors to first ascertain the integrity of the weldment and eliminates the presence of gross defects before moving on to more detailed examinations that are designed to identify internal discontinuities at specific angles. It’s essential for ensuring that any major issues are addressed before applying more intricate testing methods.