Ultrasonic Inspection
A means of locating defects in steel. When acoustic energy in the ultrasonic range is passed through steel, the sound waves tend to travel in straight lines, rather than diffusing in all directions as they do in the audible range. If there is a defect in the path of the beam it will cause a reflection of some of the energy, depleting the energy transmitted. This casts an acoustic shadow which can be monitered by a detector placed opposite the transducer or energy source. If the acoustic energy is introduced as a very short burst, then the reflected energy coming back to the originating transducer can also be used to show the size and depth of the defect. Ultrsonic techniques can be used to detect deeply located defects or those contained in the surface layer. Skill and experience are required in interpreting the results portrayed on the cathode ray tube.
