In the pulse-echo method, reflected sound at interfaces is evaluated. In this case, only one transducer is necessary, which acts as a receiver after emitting the ultrasound. If a flaw is present within the inspection volume, there is a partial or complete reflection at its interface, leading to a change in the amplitude of the back wall echo. In addition to flaw detection, thickness determination through time-of-flight measurement and material characterization through analysis of sound attenuation are possible. Various transducers with both perpendicular and angled incidence are available for the inspection.
