View source for Acoustic resonance technology

{{Short description|An acoustic inspection technology for measuring thickness}}
{{Use dmy dates|date=August 2021}}
'''Acoustic resonance technology''' ('''ART''') is an [[Acoustics|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.<ref>http://en.breivoll.no/white_papers/ {{Webarchive|url=https://archive.today/20120713173751/http://en.breivoll.no/white_papers/ |date=13 July 2012 }} Whitepaper on condition assessment of water pipes with the use of ART at Breivoll Inspection Technologies, February 2012.</ref>

ART has also been used in field tests<ref>[http://www.gassco.no/wps/wcm/connect/gassco-en/gassco/home/presse/nyhetsarkiv/29.05.09-11.06 Press release from Gassco, 29 May 2009]</ref> at [[Gassco]]'s [[Kårstø]] facility.

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. 

In 2020, Halfwave was acquired by [https://previan.com/2020/02/18/eddyfi-ndt-acquires-halfwave-its-art-technology/ Previan], who shared the technology between two of its business units, [https://www.ndt-global.com/ NDT Global], for its In-Line Inspection (ILI) solutions and [https://www.tscsubsea.com/ TSC Subsea] for subsea applications. 
 
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 [https://www.tscsubsea.com/artemis/ Artemis] solution to inspect subsea pipelines, flowlines, and flexible and rigid risers down to water depths of 3000m (10,000ft.) 

==Main features==
* Uses lower frequencies than [[ultrasonic testing]]
* Effective in gases and liquids (i.e. requires no liquid couplant)
* Can be used to characterize multi-layered media (e.g. pipelines with coatings)
* Can penetrate coatings
* Can measure inside and outside metal loss

==RUV (resonance ultrasonic vibrations)==

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, [http://www.ultrasonictech.com/ Ultrasonic Technologies Inc.] (Florida, US), and Isofoton S.A. (Spain).<ref>A. Monastyrskyi et al, "[http://www.ultrasonictech.com/publications/manuscript_PVSC_33rd.pdf Resonance Ultrasonic Vibrations for in-line crack detection in silicon wafers and solar cells]", Proc. IEEE Photovoltaic Specialists Conference, PVSC '08, pp. 1–6, May 2008, {{doi|10.1109/PVSC.2008.4922742}}.</ref> 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.

== References ==
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{{Reflist}}

[[Category:Quality]]
[[Category:Nondestructive testing]]
[[Category:Casting (manufacturing)]]
[[Category:Ultrasound]]