# 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 2.2.1: Mass of the gaseous emissions

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

The exhaust gas mass flow rate shall be measured with a constant volume sampling (CVS) system, which may use a positive displacement pump (PDP), a critical flow venturi (CFV) or a subsonic venturi (SSV).
For systems with constant mass flow (i.e. with heat exchanger), the mass of the pollutants m gas [g/test] shall be determined by means of equation (7-23):
m gas = k h · k · u gas · c gas · m ed
(7-23)
where:
u gas is the ratio between density of exhaust gas component and density of air, as given in Table 7.2 or calculated by means of equation (7-34) [-]
c gas = mean background corrected concentration of the component on a wet basis [ppm] or [% vol] respectively
k h = NOx correction factor [-], only to be applied for the NOx emission calculation
k = 1 for c gasr,w, i in [ppm], k = 10 000 for c gasr,w, i in [% vol]
m ed = total diluted exhaust gas mass over the cycle [kg/test]
For systems with flow compensation (without heat exchanger), the mass of the pollutants m gas [g/test] shall be determined by calculation of the instantaneous mass emissions, by integration and by background correction by means of equation (7-24):
m gas = k h × k × ∑ i = 1 N m ed, i × c e × u gas − m ed × c d × 1 − 1 D × u gas
(7-24)
Where:
c e emission concentration in the diluted exhaust gas, on a wet basis [ppm] or [% vol]
c d emission concentration in the dilution air, on a wet basis [ppm] or [% vol]
m ed, i mass of the diluted exhaust gas during time interval i [kg]
m ed total mass of diluted exhaust gas over the cycle [kg]
u gas tabulated value from Table 7.2 [-]
D dilution factor [see equation (7-28) of point 2.2.2.2] [-]
k h NOx correction factor [-], only to be applied for the NOx emission calculation
k 1 for c in [ppm], k = 10 000 for c in [% vol]
The concentrations c gas, c e and c d can be either values measured in a batch sample (bag, but not allowed for NOx and HC) or be averaged by integration from continuous measurements. Also m ed, i has to be averaged by integration over the test cycle.
The following equations show how the needed quantities (c e, u gas and m ed) shall be calculated.

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Source: https://www.legislation.gov.uk/eur/2017/654/annex/VII/division/2/division/2.2/division/2.2.1 (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-654/annex-VII/division-2/division-2.2/division-2.2.1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.