# 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 2.2.3: Component specific factor u

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

The component specific factor u gas of diluted gas can either be calculated by means of equation (7-34) or be taken from Table 7.2; in Table 7.2 the density of the diluted exhaust gas has been assumed equal to air density.
u = M gas M d,w × 1000 = M gas M da,w × 1 − 1 D + M r,w × 1 D × 1000
(7-34)
Where:
M gas molar mass of the gas component [g/mol]
M d,w molar mass of diluted exhaust gas [g/mol]
M da,w molar mass of dilution air [g/mol] (see equation (7-144) of point 3.9.3)
M r,w molar mass of raw exhaust gas [g/mol] (see Appendix 2 point (5)
D dilution factor [see equation (7-28) of point 2.2.2.2] [-]
Table 7.2
Diluted exhaust gas u values (for emission concentration expressed in ppm) and component densities
Depending on fuel.
At λ = 2, dry air, 273 K, 101,3 kPa.
u accurate within 0,2 % for mass composition of: C = 66 – 76 %; H = 22 – 25 %; N = 0 – 12 %.
NMHC on the basis of CH2,93 (for total HC the u gas coefficient of CH4 shall be used).
u accurate within 0,2 % for mass composition of: C3 = 70 – 90 %; C4 = 10 – 30 %.
Fuel
ρe
Gas
NOx
CO
HC
CO2
O2
CH4
ρgas [kg/m3]
2,053
1,250
1,9636
1,4277
0,716
ugas
Diesel (non-road gas-oil)
1,2943
0,001586
0,000966
0,000482
0,001517
0,001103
0,000553
Ethanol for dedicated compression ignition engines (ED95)
1,2768
0,001609
0,000980
0,000780
0,001539
0,001119
0,000561
Natural gas / bio-methane
1,2661
0,001621
0,000987
0,000528
0,001551
0,001128
0,000565
Propane
1,2805
0,001603
0,000976
0,000512
0,001533
0,001115
0,000559
Butane
1,2832
0,001600
0,000974
0,000505
0,001530
0,001113
0,000558
LPG
1,2811
0,001602
0,000976
0,000510
0,001533
0,001115
0,000559
Petrol (E10)
1,2931
0,001587
0,000966
0,000499
0,001518
0,001104
0,000553
Ethanol (E85)
1,2797
0,001604
0,000977
0,000730
0,001534
0,001116
0,000559

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Source: https://www.legislation.gov.uk/eur/2017/654/annex/VII/division/2/division/2.2/division/2.2.3 (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-654/annex-VII/division-2/division-2.2/division-2.2.3
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.