# 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 2.2.4.2: CFV-CVS system

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

The mass flow over the cycle m ed [g/test] shall be calculated by means of equation (7-37), if the temperature of the diluted exhaust gas is kept within ± 11 K over the cycle by using a heat exchanger:
m ed = 1,293 × t × K V × p p T 0,5
(7-37)
Where:
t cycle time [s]
K V calibration coefficient of the critical flow venturi for standard conditions K × m 4 × s ∕ kg
p p absolute pressure at venturi inlet [kPa]
T absolute temperature at venturi inlet [K]
1,293 kg/m3 air density at 273,15 K and 101,325 kPa
If a system with flow compensation is used (i.e. without heat exchanger), the mass of the diluted exhaust gas m ed, i [kg] during the time interval shall be calculated by means of equation (7-38):
m ed, i = 1,293 × Δ t i × K V × p p T 0,5
(7-38)
where:
Δti time interval of the test [s]
K V calibration coefficient of the critical flow venturi for standard conditions K × m 4 × s ∕ kg
p p absolute pressure at venturi inlet [kPa]
T absolute temperature at venturi inlet [K]
1,293 kg/m3 air density at 273,15 K and 101,325 kPa

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Source: https://www.legislation.gov.uk/eur/2017/654/annex/VII/division/2/division/2.2/division/2.2.4/division/2.2.4.2 (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-654/annex-VII/division-2/division-2.2/division-2.2.4/division-2.2.4.2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.