NDT : UltraSonicTesting [UT]

Ultrasonic Testing : UT

UT is performed using sound waves/ Ultrasonic waves.
Sound waves can be classified into three based on frequency:

1. Infrasonic waves (with frequency less than 20 Hz, these waves are produced by the vibration of huge bodies like earth) 
2. Audible/Sonic waves(with frequency range extends from 20 Hz to 20 KHz, only these waves are audible to human ears)
3. Ultrasonic waves(with frequency more than 20 KHz, these waves proved very useful to mankind Eg . communication , testing , Agriculture etc ..
   In UT, ultrasonic waves when forced to propagate through the test material gets reflected back either from the defective region (cracks) or from the backside of the test material. The reflected waves is received using transducers processed to analyzed and understand about the defects in the material.