# 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 3.7.1: Sampling

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

(a) Sampling from a varying flow rate:
If a batch sample from a changing exhaust gas flow rate is collected, a sample proportional to the changing exhaust gas flow rate shall be extracted. The flow rate shall be integrated over a test interval to determine the total flow. The mean PM concentration M – PM (which is already in units of mass per mole of sample) shall be multiplied by the total flow to obtain the total mass of PM m PM [g] by means of equation (7-121):
m PM = M – PM × ∑ i = 1 N ṅ i × Δ t i
(7-121)
Where:
ṅi instantaneous exhaust gas molar flow rate [mol/s]
M – PM mean PM concentration [g/mol]
Δti sampling interval [s]
(b) Sampling from a constant flow rate
If a batch sample from a constant exhaust gas flow rate is collected, the mean molar flow rate from which the sample is extracted shall be determined. The mean PM concentration shall be multiplied by the total flow to obtain the total mass of PM m PM[g] by means of equation (7-122):
m PM = M – PM × ṅ × Δ t
(7-122)
where:
ṅ exhaust gas molar flow rate [mol/s]
M – PM mean PM concentration [g/mol]
Δt time duration of test interval [s]
For sampling with a constant dilution ratio (DR), m PM [g] shall be calculated by means of equation (7-123):
m PM = m PMdil × DR
(7-123)
where:
m PMdil PM mass in dilution air [g]
DR dilution ratio [-] defined as the ratio between the mass of the emission m and the mass of diluted exhaust gas m dil/exh (DR = m/m dil/exh).
The dilution ratio DR can be expressed as a function of x dil/exh [equation (7-124)]:
DR = 1 1 − x dil ∕ exh
(7-124)

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Source: https://www.legislation.gov.uk/eur/2017/654/annex/VII/division/3/division/3.7/division/3.7.1 (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-654/annex-VII/division-3/division-3.7/division-3.7.1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.