# 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 3.5.1: Mass of gaseous emissions

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

To calculate the total mass per test of gaseous emission m gas [g/test], its molar concentration shall be multiplied by its respective molar flow and by exhaust gas molar mass; then integration over test cycle shall be performed [equation (7-104)]:
m gas = M gas × ∫ ṅ exh × x gas × d t
(7-104)
Where:
M gas molar mass of the generic gaseous emission [g/mol]
ṅ exh instantaneous exhaust gas molar flow rate on a wet basis [mol/s]
x gas instantaneous generic gas molar concentration on a wet basis [mol/mol]
t time [s]
Since equation (7-104) has to be solved by numerical integration, it is transformed in equation (7-105):
m gas = M gas × ∫ ṅ exh × x gas × d t ⇒ m gas = 1 ƒ × M gas × ∑ i = 1 N ṅ exh i × x gas i
(7-105)
Where:
M gas generic emission molar mass [g/mol]
ṅ exh i instantaneous exhaust gas molar flow rate on a wet basis [mol/s]
x gas i instantaneous generic gas molar concentration on a wet basis [mol/mol]
ƒ data sampling rate [Hz]
N number of measurements [-]
General equation may be modified according to which measurement system is used, batch or continuous sampling, and if a varying rather than a constant flow rate is sampled.
(a) For continuous sampling, in the general case of varying flow rate, the mass of the gaseous emission m gas [g/test] shall be calculated by means of equation (7-106):
m gas = 1 ƒ × M gas × ∑ i = 1 N ṅ exh i × x gas i
(7-106)
Where:
M gas generic emission molar mass [g/mol]
ṅ exh i instantaneous exhaust gas molar flow rate on a wet basis [mol/s]
x gas i instantaneous gaseous emission molar fraction on a wet basis [mol/mol]
ƒ data sampling rate [Hz]
N number of measurements [-]
(b) Still for continuous sampling but in the particular case of constant flow rate the mass of the gaseous emission m gas [g/test] shall be calculated by means of equation (7-107):
m gas = M gas × ṅ exh × x – gas × Δ t
(7-107)
Where:
M gas generic emission molar mass [g/mol]
ṅ exh exhaust gas molar flow rate on a wet basis [mol/s]
x – gas mean gaseous emission molar fraction on a wet basis [mol/mol]
Δt time duration of test interval
(c) For the batch sampling, regardless the flow rate is varying or constant, equation (7-104) can be simplified by means of equation (7-108):
m gas = 1 ƒ × M gas × x – gas × ∑ i = 1 N ṅ exh i
(7-108)
Where:
M gas generic emission molar mass [g/mol]
ṅ exh i instantaneous exhaust gas molar flow rate on a wet basis [mol/s]
x – gas mean gaseous emission molar fraction on a wet basis [mol/mol]
ƒ data sampling rate [Hz]
N number of measurements [-]

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Source: https://www.legislation.gov.uk/eur/2017/654/annex/VII/division/3/division/3.5/division/3.5.1 (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-654/annex-VII/division-3/division-3.5/division-3.5.1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.