{
  "url": "https://openlegislation.uk/eu-regulation-2017-654/annex-VII/division-2/division-2.1/division-2.1.6/division-2.1.6.3",
  "json_url": "https://openlegislation.uk/eu-regulation-2017-654/annex-VII/division-2/division-2.1/division-2.1.6/division-2.1.6.3.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/2.1/division/2.1.6/division/2.1.6.3",
  "kind": "division",
  "number": "2.1.6.3",
  "heading": "Air flow and air to fuel ratio measurement method",
  "text": "This involves exhaust gas mass calculation from the air flow and the air to fuel ratio. The instantaneous exhaust gas mass flow q mew, i [kg/s] shall be calculated by means of equation (7-17):\nq m ew, i = q m aw, i × 1 + 1 A ∕ F st × λ i\n(7-17)\nwith:\nA ∕ F st = 138,0 × 1 + α 4 − ε 2 + γ 12,011 + 1,00794 × α + 15,9994 × ε + 14,0067 × δ + 32,065 × γ\n(7-18)\nλ i = 100 − c COd × 10 − 4 2 − c HCw × 10 − 4 + α 4 × 1 − 2 × c COd × 10 − 4 3,5 × c CO2d 1 + c COd × 10 − 4 3,5 × c CO2d − ε 2 − δ 2 × c CO2d + c COd × 10 − 4 4,764 × 1 + α 4 − ε 2 + γ × c CO2d + c COd × 10 − 4 + c HCw × 10 − 4\n(7-19)\nwhere:\nqm aw, i wet intake air mass flow rate [kg/s]\nA/F st stoichiometric air-to-fuel ratio [-]\nλi instantaneous excess air ratio [-]\nc COd concentration of CO in the raw exhaust gas on a dry basis [ppm]\nc CO2d concentration of CO2 in the raw exhaust gas on a dry basis [per cent]\nc HCw concentration of HC in the raw exhaust gas on a wet basis [ppm C1]\nα molar hydrogen-to-carbon ratio [-]\nδ molar nitrogen-to-carbon ratio [-]\nε molar oxygen-to-carbon ratio [-]\nγ atomic sulphur-to-carbon ratio [-]",
  "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/2.1/division/2.1.6/division/2.1.6.3",
    "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."
}