About NDTimes Ultrasound inspection as a quality tool has become quite popular and effective in thickness measurement, flaw detection, and material characterization.
Most systems utilize transducers which generate longitudinal or shear waves.
These systems are very effective at detecting anomalies along the sound path. However, the sound path traverses only a small portion of the volume of the part, so the transducer is mechanically scanned to interrogate the entire volume. This is time consuming and, if done improperly, can miss areas. However, in those situations involving inspection of sheet or tubular materials, an alternate inspection method utilizing Guided Waves may be more suitable. Guided Waves are waves whose propagation characteristics depend on structural boundaries such as those in plates, tubes, rods, and embedded layers.