nitrox

A diving cylinder (scuba tank) with a nitrox label (sense 2)

Nitrox stickers (sense 2) for attaching to diving cylinders

Blend of nitro(gen) +‎ ox(ygen). Analyzable as nitro- +‎ ox

• (Received Pronunciation) IPA^(key): /ˈnaɪtɹɒks/

  • Audio (Southern England):

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• (General American) IPA^(key): /ˈnaɪtɹɑks/
• Hyphenation: nitr‧ox

nitrox (uncountable)

1. (metallurgy) An industrial process for case hardening (imparting greater surface hardness to) metal objects, involving nitrocarburizing (the diffusion of carbon and nitrogen into the metal) followed by oxidation.
   • 1988, Robert B Ross, “‘Nitrox’”, in Handbook of Metal Treatments and Testing, 2nd edition, London, New York, N.Y.: Chapman and Hall, →ISBN, part 1 (A–Z of Treatment and Testing Processes), page 209:

     The ‘nitrox’ process basically supplies the surface hardness of the sursulf process, which is essentially carbonitriding, and then oxidizes it. The oxide is adherent and thus considerably increases the corrosion resistance.

   • 2007 April 3, John McCollum, Integrated Circuit Wafer with Inter-die Metal Interconnect Lines Traversing Scribe-line Boundaries, US Patent Application 20070184635A1 (PDF version), paragraph 0022, page 2, column 2:

     Two other materials-based approaches may be employed in the present invention. One is to use highly doped glass (with boron or phosphorus) or plasma nitride (otherwise known as nitrox) as the inter-metal layer insulator.

   • 2008 September, Malgorzata Przylecka, Wojciech Gęstwa, L. C. F. Canale, Xin Yao, G. E. Totten, “Sources of Failures in Carburized and Carbonitrided Components”, in L. C. F. Canale, R. A. Mesquita, G. E. Totten, editors, Failure Analysis of Heat Treated Steel Components, Materials Park, Oh.: ASM International, →ISBN, page 178, column 1:

     Carbonitriding processes are typically conducted in either a gas (ammonia) or a salt bath based on trade names such as Tufftride, Nitrotec, and Nitrox. Alternatively, a plasma nitriding process may be conducted.

2. (underwater diving) A mixture of nitrogen and oxygen, the nitrogen content being lower than that of normal air, which is used in place of air as a breathing gas.
   • 1989 September, “Abstract”, in R. W. Hamilton, Dudley J. Crosson, Alan W. Hulbert, editors, Workshop on Enriched Air Nitrox Diving (National Undersea Research Program Research Report; 89-1), Rockville, Md.: Office of Undersea Research, Oceanic and Atmosphere Research, National Oceanic and Atmospheric Administration, U.S. Department of Commerce, →OCLC, page 1:

     "Enriched air" or "nitrox" is a mixture of air and oxygen; the oxygen component ranges to about 50% but is used normally at 32 to 40%. [...] Safe enriched air nitrox diving practices established for the scientific diving community might be of some value and could help avoid accidents due to ignorance of its hazards and use of improper procedures.

   • 1991 October, “Appendix D: NOAA Nitrox I Diving and Decompression Tables”, in NOAA Diving Manual: Diving for Science and Technology, Silver Spring, Md.: Office of Undersea Research, Oceanic and Atmosphere Research, National Oceanic and Atmospheric Administration, U.S. Department of Commerce, →OCLC, page D-1:

     NOAA Nitrox I is a standard breathing gas mixture of 32% oxygen (±1%); the balance of the gas (68%) is nitrogen. [...] High-pressure storage cylinders, scuba tanks, regulators, and all high-pressure gas transfer equipment that is used with pure oxygen or with nitrox mixtures that contain more than 40 percent oxygen must be cleaned and maintained for oxygen service.

   • 2004, Michael B. Strauss, Igor V. Aksenov, Diving Science, Champaign, Ill.: Human Kinetics, →ISBN, page 35:

     Is there a compromise between too much oxygen and too much inert gas? The answer is the use of enriched air nitrox (enriched air) mixtures in the SCUBA tank. The two most commonly used mixtures are 32 percent and 36 percent oxygen mixtures. [...] he increased oxygen percentages make the diver using nitrox mixtures more subject to oxygen seizures. With nitrox mixtures, the relative increase in oxygen percentage is over three times the relative decrease in nitrogen percentage.

   • 2016, Carl Edmonds, Michael Bennett, John Lippmann, Simon J. Mitchell, “Technical Diving”, in Diving and Subaquatic Medicine, 5th edition, Boca Raton, Fla.: CRC Press, →ISBN, part 10 (Specialized Diving and Its Problems), page 705:

     [N]itrox is often referred to as ‘enriched air’ or ‘enriched air – nitrox’ (EANx). By convention, the mix is described by reference to its oxygen content. Thus, if a nitrox mix contains 36 per cent oxygen, then it is referred to as ‘nitrox 36’ (‘Nx36’) or ‘EANx36’. [...] he nitrox diver can use the reduced absorption of nitrogen to increase allowable dive time by using the EAD to derive the no-decompression limit for the dive or as a basis for calculating decompression. This approach allows longer dives and shorter decompression.

• (mixture of nitrogen and oxygen): heliair, heliox, trimix

• nitrox on Wikipedia.Wikipedia