{
  "url": "https://openlegislation.uk/eu-regulation-2017-654/annex-VII/division-3/division-3.3/division-3.3.1",
  "json_url": "https://openlegislation.uk/eu-regulation-2017-654/annex-VII/division-3/division-3.3/division-3.3.1.json",
  "legislation": "eur/2017/654",
  "legislation_title": "Commission Delegated Regulation (EU) 2017/654 of 19 December 2016 supplementing Regulation (EU) 2016/1628 of the European Parliament and of the Council with regard to technical and general requirements relating to emission limits and type-approval for internal combustion engines for non-road mobile machinery",
  "legislation_url": "https://openlegislation.uk/eu-regulation-2017-654",
  "path": "annex/VII/division/3/division/3.3/division/3.3.1",
  "kind": "division",
  "number": "3.3.1",
  "heading": "Dry air and chemical species",
  "text": "This section uses the following values for dry air composition:\nx O2airdry = 0,209445 mol/mol\nx Arairdry = 0,00934 mol/mol\nx N2airdry = 0,78084 mol/mol\nx CO2airdry = 375 μmol/mol\nThis section uses the following molar masses or effective molar masses of chemical species:\nM air 28,96559 g/mol (dry air)\nM Ar 39,948 g/mol (argon)\nM C 12,0107 g/mol (carbon)\nM CO 28,0101 g/mol (carbon monoxide)\nM CO2 44,0095 g/mol (carbon dioxide)\nM H 1,00794 g/mol (atomic hydrogen)\nM H2 2,01588 g/mol (molecular hydrogen)\nM H2O 18,01528 g/mol (water)\nM He 4,002602 g/mol (helium)\nM N 14,0067 g/mol (atomic nitrogen)\nM N2 28,0134 g/mol (molecular nitrogen)\nM NOx 46,0055 g/mol (oxides of nitrogen (*))\nM O 15,9994 g/mol (atomic oxygen)\nM O2 31,9988 g/mol (molecular oxygen)\nM C3H8 44,09562 g/mol (propane)\nM S 32,065 g/mol (sulphur)\nM HC 13,875389 g/mol (total hydrocarbon (**))\nThis section uses the following molar gas constant R for ideal gases:\nR = 8,314472J (mol · K)\nThis section uses the following ratios of specific heats γ [J/(kg · K)]/[J/(kg · K)] for dilution air and diluted exhaust:\nγ air 1,399 (ratio of specific heats for intake air or dilution air)\nγ dil 1,399 (ratio of specific heats for diluted exhaust gas)\nγ exh 1,385 (ratio of specific heats for raw exhaust gas)",
  "extent": "E+W+S+N.I.",
  "status": null,
  "version": "current",
  "annotations": [],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/eur/2017/654/annex/VII/division/3/division/3.3/division/3.3.1",
    "retrieved_at": "2026-11-01T14:45:01.864924+00:00"
  },
  "licence": "Open Government Licence v3.0",
  "licence_url": "https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
  "attribution": "Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives."
}