0° Compression Waves: principle def

0° Compression Waves: principle defect detection mechanism for Technique 1 and 2 is byspecular reflection of ultrasound from the face of ultrasonically smooth planar defects and byscattering of the ultrasound from the face of ultrasonically rough planar defects.Technique 1: a pulse-echo inspection technique applied from the external cylindrical surfaceof the MCL Hot Leg to SG Inlet Safe End Weld (Beams 1), GEIT B2S-EN (0°) single-crystallongitudinal wave beams pointing down into the weld in the Radial (-R-axis) direction,scanning in both Axial (± Z) direction towards the centre of the MCL Hot Leg to SG InletNozzle Safe End weld, rastering in the Azimuthal (+θ) direction around the pipe section.Technique 2: a pulse-echo inspection technique applied from the external cylindrical surfaceof the MCL Hot Leg to SG Inlet Safe End Weld (Beams 2), GEIT MSEB4-EN (0°)twin-crystal longitudinal wave beams pointing down into the weld in the Radial (-R-axis)direction, scanning in both Axial (± Z) direction towards the centre of the MCL Hot Leg toSG Inlet Nozzle Safe End weld for the full width of the inspection volume, whilemaintaining the 10% beam width overlap increment when rastering in the Azimuthal (+θ)direction around the pipe section.b) Angled Shear Waves: are designed to detect defects in the HAZ and defects aligned alongthe weld bevel faces from the nearest side of the weld. The principle defect detectionmechanism for Technique 3 to 5 is by specular reflection of ultrasound from the face ofultrasonically smooth planar defects and by scattering of the ultrasound from the face ofultrasonically rough planar defects as well as Technique 3 (45°/49°) ‘Corner Trap’ responsecapabilities for surface-breaking defects on or near-surface opposite scanning surface. Thesecondary defect detection mechanism for Techniques 3 to 5 is by diffracted signals from thetop and bottom tips of the defect for both ultrasonically rough and smooth planar defects.Technique 3: