What type of waves are typically used in Ultrasonic Testing?

Ultrasonic Testing (UT) primarily utilizes sound waves to detect imperfections or characteristics within materials. These sound waves, specifically ultrasonic waves, are typically above the frequency range of human hearing, generally above 20 kHz. By generating high-frequency sound waves and transmitting them into the test material, UT can examine various properties such as thickness, density, and the presence of flaws like cracks or voids.

Ultrasonic waves travel through the material and reflect off any discontinuities. The time it takes for the waves to return to the transducer can be measured, which provides valuable information about the type, location, and size of defects. This application is vital in industries where the integrity of materials is crucial, such as aerospace, automotive, and manufacturing.

The other options do not pertain to the techniques used in Ultrasonic Testing. Electromagnetic waves are used in different nondestructive testing methods, like eddy current testing. X-rays are associated with radiographic testing, which involves using ionizing radiation to inspect materials. Optical waves, while applicable in certain optical testing methods, do not relate to the sound-based principle core to Ultrasonic Testing.