Define the procedure to determine flaw by transducer.

Procedure to find flaw:

Cross section of typical contact transducer

Ultrasonic flaw detection is fundamentally a comparative technique. By using suitable reference standards including knowledge of sound wave propagation and usually accepted test procedures, a trained operator knows exact echo patterns corresponding to the echo response through good parts and through representative flaws. The echo pattern through a test piece may after that, be compared to the patterns from such calibration standards to find out its condition.