# 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, Appendix 6

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

Ammonia emission calculation
1.
Calculation of the mean concentration for transient (NRTC and LSI-NRTC) test cycles and RMC
The mean NH3 concentration in the exhaust gas over the test cycle cNH3 [ppm] shall be determined by integrating the instantaneous values over the cycle. Equation (7-179) shall be applied:
c NH3 = 1 n ∑ i = 1 i = n c NH3,i
(7-179)
Where:
cNH3,i is the instantaneous NH3 concentration in the exhaust gas [ppm]
n is the number of measurements
For the NRTC, the final test result shall be calculated by means of equation (7-180):
c NH3 = (0,1 × c NH3,cold ) + (0,9 × c NH3,hot )
(7-180)
Where:
cNH3,cold is the mean NH3 concentration of the cold-start NRTC [ppm]
cNH3,hot is the mean NH3 concentration of the hot-start NRTC [ppm]
2.
Calculation of the mean concentration for discrete-mode NRSC
The mean NH3 concentration in the exhaust gas over the test cycle cNH3 [ppm] shall be determined by measuring the mean concentration for each mode and weighting the result in accordance with the weighting factors applicable to the test cycle. Equation (7-181) shall be applied:
c NH3 = ∑ i = 1 N mode c – NH3,i × WF i
(7-181)
Where:
c – NH3,i is the mean NH3 concentration in the exhaust gas for mode i [ppm]
Nmode is the number of modes in the test cycle
WFi is the weighting factor for the mode i [-]

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Source: https://www.legislation.gov.uk/eur/2017/654/annex/VII/appendix/6 (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-654/annex-VII/appendix-6
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.