Which statement is true regarding angle beam inspections of a weld?

The statement regarding angle beam inspections of a weld that is true is that all scan surfaces must be free of weld spatter, surface irregularities, and foreign matter. This is crucial for accurate ultrasonic testing, as any contaminants or irregular features on the surface can interfere with the sound waves used during the inspection. Such obstructions can create false signals or hinder the ability to detect actual defects within the weld, leading to an unreliable assessment of the weld quality.

Having a clean scanning surface ensures that the ultrasonic waves can penetrate the material properly and that reflections from potential defects are not masked by surface noise or irregularities. This principle is fundamental in ensuring the integrity and reliability of the inspection process. Therefore, maintaining a clean inspection surface is a key requirement for effective angle beam inspections in welds.