For shear wave weld inspection, the zero point on the flaw locating rule should coincide with the sound beam exit point of the wedge.

For shear wave weld inspection, the zero point on the flaw locating rule should coincide with the sound beam exit point of the wedge.

• A. Sound beam exit point of the wedge
• B. Point directly over the flaw
• C. Wheel search unit
• D. Circular scanner

Answer: (A)

In this setup, the key idea is having a fixed, reproducible origin for locating flaws along the weld. The ultrasound wave enters the material from the wedge at a specific, known point. Setting the zero point at that wedge exit aligns the along-weld position measurement with the actual path the wave travels from the moment it enters the metal. As echoes come back, their time of flight is converted to a distance along the weld from that exit point, so any reflector’s location is read directly as how far it lies from where the wave first entered. This makes flaw positions consistent across scans and interpretable with the weld geometry and wedge setup. Other options describe equipment or a flaw’s location itself, rather than a fixed reference from which to measure along the weld, so they don’t provide the stable origin needed for accurate localization.

In this setup, the key idea is having a fixed, reproducible origin for locating flaws along the weld. The ultrasound wave enters the material from the wedge at a specific, known point. Setting the zero point at that wedge exit aligns the along-weld position measurement with the actual path the wave travels from the moment it enters the metal. As echoes come back, their time of flight is converted to a distance along the weld from that exit point, so any reflector’s location is read directly as how far it lies from where the wave first entered. This makes flaw positions consistent across scans and interpretable with the weld geometry and wedge setup.

Other options describe equipment or a flaw’s location itself, rather than a fixed reference from which to measure along the weld, so they don’t provide the stable origin needed for accurate localization.