Among all the applications of industrial ultrasonic testing there are, flaw detection is perhaps the most commonly used and some say most efficient technique there is. This application uses high frequency sound waves that are reflected from an object’s flaws and that then generate clear echo patterns that are interpreted by those who are trained to do so. Let’s look at some time to look at the basic theories, practices and applications of this technique.

The Fundamental Theory

All sound waves oscillate at a specific frequency, or number of vibrations or cycles per second, which we experience as pitch in the familiar range of audible sound. Human hearing – which is approximately 20Hz to 20,000Hz – is actually just a very small part of the sound spectrum. Ultrasonic flaw detection applications use frequencies between 500 KHz and 10 MHz per second. Waves pass through a medium at a particular velocity in an expected direction. When theses waves collide with a boundary having a different medium they are transmitted back with different characteristics. This is the very basic principle behind ultrasonic flaw detection.

Procedure of Ultrasonic Flaw Detection

Ultrasonic Flaw Detection requires a trained operator to be able to identify particular echo patterns related to the echo response from representative flaws. Two calibration standards are used in ultrasonic flaw detection. Those are straight beam testing and angle beam testing. The latter is often used in weld inspection.


Flaw detection is and can be applied in a wide range of industries. Obviously, equipment such as our ultrasonic gantry system and ultrasonic bubbler system are designed for the aerospace industry but the principles of flaw detection can be applied to petrochemical oil and gas pipelines, storage tanks and power generation including nuclear power facilities. The advantages of ultrasonic flaw detection testing include:

  • Access is only required from one side for pulse-echo mode
  • The depth of penetration is superior to other methodsalert
  • Highly accurate flaw sizing and shape
  • Minimal part preparation is required.
  • Results are in real-time

Ultrasonic flaw detection is highly effective and offers engineers enhanced stability and accuracy. Additionally, flaw detection utilizes state-of-the-art equipment that can detect errors much faster than most other methods. This guides mechanics in repairing and servicing aircraft and aids manufactures in the design and manufacture of systems and components long before costly and potentially calamitous problems develop. Much of that equipment we have on our site.