Ultrasonic testing (UT) has been practiced for many decades. Initial rapid developments in instrumentation encouraged by the technological advances from the 1950's continue today. Through the 1980's and continuing through the present, computers have provided technicians with smaller and more rugged instruments with greater capabilities.
NDT ultrasonic Testing uses high frequency sound energy to conduct examinations and make measurements. This type of inspection can be used for flaw detection, dimensional measurements, material characterization, and more. In industrial applications, ultrasonic testing is commonly used on metals, plastics, composites, and ceramics. The only common engineering materials that are not suitable for ultrasonic testing with normal tools are wood and paper products. Ultrasonic technology is also usually used in the biomedical field for diagnostic imaging and medical research.
In the late 1940s, researchers in Japan pioneered the use of ultrasonic testing in medical diagnostics using early B-scan equipment that provided a two-dimensional profile image of tissue layers. By the 1960s, early versions of medical scanners were being used to detect and outline tumors, gallstones, and similar conditions. In the 1970s, the introduction of precision thickness gages brought ultrasonic testing to a wide variety of manufacturing operations that required thickness measurement of parts in situations where there was access to only one side, and corrosion gages came into wide use for measurement of remaining wall thickness in metal pipes and tanks.
Ultrasonic is also used to detect anomalies in weld inspections.