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Czechoslovak Journal of Physics

, Volume 46, Supplement 5, pp 2779–2780 | Cite as

Helium gas purity monitor based on low frequency acoustic resonance

  • S. Kasthurirengan
  • S. Jacob
  • R. Karunanithi
  • A. Karthikeyan
Techniques and Applications Instrumentation
  • 52 Downloads

Abstract

Monitoring gas purity is an important aspect of gas recovery stations where air is usually one of the major impurities. Purity monitors of Katherometric type are commercially available for this purpose. Alternatively, we discuss here a helium gas purity monitor based on acoustic resonance of a cavity at audio frequencies. It measures the purity by monitoring the resonant frequency of a cylindrical cavity filled with the gas under test and excited by conventional telephone transducers fixed at the ends. The use of the latter simplifies the design considerably. The paper discusses the details of the resonant cavity and the electronic circuit along with temperature compensation. The unit has been calibrated with helium gas of known purities. The unit has a response time of the order of 10 minutes and measures the gas purity to an accuracy of 0.02%. The unit has been installed in our helium recovery system and is found to perform satisfactorily.

Keywords

Resonant Cavity Cylindrical Cavity Temperature Compensation Acoustic Resonance Audio Frequency 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

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    J.C. Fraser, Rev. Sci. Instrum. 43 (1972) 1692.CrossRefGoogle Scholar
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    R. Keolin, S. Garret, J. Maynard and I. Rudnick, J. Acoust. Soc. Am. 64 (1978) 561.Google Scholar
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    S.L. Garret, G.W. Swift and R.E. Packard, Physica 107B (1981) 601.Google Scholar

Copyright information

© Institute of Physics, Acad. Sci. CR 1996

Authors and Affiliations

  • S. Kasthurirengan
    • 1
  • S. Jacob
    • 1
  • R. Karunanithi
    • 1
  • A. Karthikeyan
    • 1
  1. 1.Central Cryogenic FacilityIndian Institute of ScienceBangaloreIndia

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