{
  "url": "https://openlegislation.uk/eu-regulation-2017-654/annex-VII/division-2/division-2.2/division-2.2.2/division-2.2.2.2",
  "json_url": "https://openlegislation.uk/eu-regulation-2017-654/annex-VII/division-2/division-2.2/division-2.2.2/division-2.2.2.2.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/2/division/2.2/division/2.2.2/division/2.2.2.2",
  "kind": "division",
  "number": "2.2.2.2",
  "heading": "Dilution factor",
  "text": "The dilution factor D [-] (which is necessary for the background correction and the k w2 calculation) shall be calculated by means of equation (7-28):\nD = F s c CO2,e + c HC,e + c CO,e × 10 − 4\n(7-28)\nwhere:\nF S stoichiometric factor [-]\nc CO2,e concentration of CO2 in the diluted exhaust gas on a wet basis [per cent vol]\nc HC,e concentration of HC in the diluted exhaust gas on a wet basis [ppm C1]\nc CO,e concentration of CO in the diluted exhaust gas on a wet basis [ppm]\nThe stoichiometric factor shall be calculated by means of equation (7-29):\nF s = 100 × 1 1 + α 2 + 3,76 × 1 + α 4\n(7-29)\nWhere:\nα molar hydrogen to carbon ratio in the fuel [-]\nAlternatively, if the fuel composition is not known, the following stoichiometric factors may be used:\nF S (diesel) = 13,4\nFS (LPG) = 11,6\nFS (NG) = 9,5\nFS (E10) = 13,3\nFS (E85) = 11,5\nIf a direct measurement is made of the exhaust gas flow, the dilution factor D [-] may be calculated by means of equation (7-30):\nD = q V CVS q V ew\n(7-30)\nWhere:\nqV CVS is the volumetric flow rate of diluted exhaust gas [m3/s]\nqV ew = volumetric flow rate of raw exhaust gas [m3/s]",
  "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/2/division/2.2/division/2.2.2/division/2.2.2.2",
    "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."
}