# 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, Division 2.2.2.1: Diluted exhaust gas

Extent: E+W+S+N.I.

Dry concentrations shall be converted to wet concentrations by means of one of the following two equations [(7-25) or (7-26)] applied to equation:
k w,e = 1 − α × c CO2w 200 − k w2 × 1,008
(7-25)
or
k w,e = 1 − k w2 1 + α × c CO2d 200 × 1,008
(7-26)
where:
α molar hydrogen to carbon ratio of the fuel [-]
c CO2w concentration of CO2 in the diluted exhaust gas on a wet basis [per cent vol]
c CO2d concentration of CO2 in the diluted exhaust gas on a dry basis [per cent vol]
The dry to wet correction factor k w2 takes into consideration the water content of both intake air and dilution air and shall be calculated by means of equation (7-27):
k w2 = 1,608 × H d × 1 − 1 D + H a × 1 D 1000 + 1,608 × H d 1 − 1 D + H a × 1 D
(7-27)
where:
H a intake air humidity [g H2O/kg dry air]
H d dilution air humidity [g H2O/kg dry air]
D dilution factor [see equation (7-28) of point 2.2.2.2] [-]

---
Source: https://www.legislation.gov.uk/eur/2017/654/annex/VII/division/2/division/2.2/division/2.2.2/division/2.2.2.1 (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-654/annex-VII/division-2/division-2.2/division-2.2.2/division-2.2.2.1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.