Ultrasonic testing is a method that uses ultrasonic sound waves with high frequencies ranging from 0.1 - 20 MHz, well above the audible range for hearing (20Hz - 20 KHz). These waves can be directed at materials to detect flaws, potentially invisible to the naked eye.

The process works by utilizing the directional nature of sound waves, by projecting them at a material, they'll travel in a straight line through a material until they encounter a surface with another medium (such as air) which will then cause them to reflect back. These reflections can be measured and used to find flaws such as cracks in materials.

Ultrasonic testing can be used on a wide range of materials, commonly, metal, plastics, composites and ceramics. The only real exceptions being wood and paper.

Ultrasonic is a non-destructive testing method, meaning that the method poses stresses well below the elastic limit of the material, and poses no danger of damage or degradation. This is often useful when a flaw may require sensitive investigation. And also comes in handy when looking for flaws in general.

The piece in question does not have to be cut, sectioned, or exposed to damaging chemicals. Access from only one side is required, as opposed to tools such as micrometers and calipers. There are no potential hazards involved, and the tests and highly repeatable and reliable once set up.

Ultrasonic testing does run into problems however when the geometries involved are complex. Testing across different materials will also require different setups and re-calibration of equipment. The process also requires a trained operator, who can interpret the results and is more expensive than mechanical alternatives for applications such as thickness measurement. However, can save money and prevent losses in the long run by detecting flaws early.

Ultrasonic flaw detection is one of the major applications of the technology, and widely used in critical safety related and quality related capacities.

Flaws such as cracks, voids, bonds, inclusions and similar flaws that pose risks to the structural integrity can be detected.

As you can see the benefits are numerous and provide us with highly useful tools for analysis, safety and money saving within industry. Ultrasonic is often applied to petroleum, chemical engineering and power plants, on equipment such as welds, beams, pipelines, tanks, turbines any many other essential items.

The largest gains come from preventing outages, through regular testing and rapid response to diagnosing emergency problems quickly and efficiently. In the long run the money saved can be substantial.