Acoustic resonance technology (ART) is an acoustic inspection technology developed by Det Norske Veritas over the past 20 years. ART exploits the phenomenon of half-wave resonance, whereby a suitably excited resonant target (such as a pipeline wall) exhibits longitudinal resonances at certain frequencies characteristic of the target's thickness. Knowing the speed of sound in the target material, the half-wave resonant frequencies can be used to calculate the target's thickness.
ART differs from traditional ultrasonic testing: although both are forms of nondestructive testing based on acoustics, ART generally uses lower frequencies and has a wider bandwidth. This has enabled its use in gaseous environments without a liquid couplant.
Det Norske Veritas has licensed the technology for use in on-shore water pipes worldwide to Breivoll Inspection Technologies AS. Breivoll has proven the efficiency of the technology in assessing the condition of metallic water pipes, both with and without coating. The company has since 2008 successfully developed a method to enter and inspect water mains, and is a world-leader in their market. 
In 2012, DNV's ART activities were spun out into a subsidiary, HalfWave, and was further developed through investment by Shell Technology Ventures, Chevron Technology Ventures, and Energy Ventures.
TSC Subsea has a long history of developing subsea inspection robotics, deploying multiple non-destructive testing (NDT) techniques. Since the merger, substantial enhancements have been made to the ART technology. As a result, Acoustic Resonance Technology has proven to penetrate thick subsea attenuative coatings of more than 100mm (4 inches).
TSC Subsea has successfully deployed ART with its Artemis solution to inspect subsea pipelines, flowlines, and flexible and rigid risers down to water depths of 3000m (10,000ft.)
In a closely related technique, the presence of cracks in a solid structure can be detected by looking for differences in resonance frequency, bandwidth and resonance amplitude compared to a nominally identical but non-cracked structure. This technique, called RUV (Resonance Ultrasonic Vibrations), has been developed for use in the photovoltaics industry by a group of researchers from the University of South Florida, Ultrasonic Technologies Inc. (Florida, US), and Isofoton S.A. (Spain).  The method was able to detect mm-size cracks in as-cut and processed silicon wafers, as well as finished solar cells, with a total test time of under 2 seconds per wafer.