# 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 7.8.1.2: Performing discrete-mode NRSC

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

(a) The test shall be performed in ascending order of mode numbers as set out for the test cycle (see Appendix 1 of Annex XVII);
(b) Each mode has a mode length of at least 10 minutes. In each mode the engine shall be stabilised for at least 5 minutes. Gaseous emissions, and, where applicable, PN, shall be sampled for 1 to 3 minutes at the end of each mode and PM emissions shall be sampled in accordance with point (c);
Notwithstanding the previous paragraph, when either testing spark ignition engines using cycles G1, G2 or G3 or when conducting measurements in accordance with Annex V of this Regulation each mode has a mode length of at least 3 minutes. In this case gaseous emissions, and, where applicable, PN, shall be sampled for at least the last 2 minutes of each mode and PM emissions shall be sampled in accordance with point (c). The mode length and sampling time may be extended to improve accuracy;
The mode length shall be recorded and reported.
(c) For PM emissions, the PM sampling may be done either with the single filter method or with the multiple filter method. Since the results of the methods may differ slightly, the method used shall be declared with the results;
For the single filter method the modal weighting factors specified in the test cycle procedure and the actual exhaust gas flow shall be taken into account during sampling by adjusting sample flow rate and/or sampling time, accordingly. It is required that the effective weighing factor of the PM sampling is within ± 0,005 of the weighing factor of the given mode;
Sampling shall be conducted as late as possible within each mode. For the single filter method, the completion of PM sampling shall be coincident within ± 5 s with the completion of the gaseous emission measurement. The sampling time per mode shall be at least 20 s for the single filter method and at least 60 s for the multi-filter method. For systems without bypass capability, the sampling time per mode shall be at least 60 s for single and multiple filter methods;
(d) The engine speed and load, intake air temperature, fuel flow and where applicable air or exhaust gas flow shall be measured for each mode at the same time interval which is used for the measurement of the gaseous concentrations;
Any additional data required for calculation shall be recorded.
(e) If the engine stalls or the emission sampling is interrupted at any time after emission sampling begins for a discrete-mode NRSC and the single filter method, the test shall be voided and be repeated beginning with the engine warm-up procedure. In the case of PM measurement utilizing the multi-filter method (one sampling filter for each operating mode), the test shall be continued by stabilizing the engine at the previous mode for engine temperature conditioning and then initiating measurement with the mode where the engine stalled;
(f) Post-test procedures according to point 7.3.2 shall be performed.

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Source: https://www.legislation.gov.uk/eur/2017/654/annex/VI/division/7/division/7.8/division/7.8.1/division/7.8.1.2 (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-654/annex-VI/division-7/division-7.8/division-7.8.1/division-7.8.1.2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.