# 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 7.3.1.1: General requirements for preconditioning the sampling system and the engine

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

To achieve stable conditions, the sampling system and the engine shall be preconditioned before starting a test sequence as specified in this point.
The intent of engine preconditioning is to achieve the representativeness of emissions and emission controls over the duty cycle and to reduce bias in order to meet stable conditions for the following emission test.
Emissions may be measured during preconditioning cycles, as long as a predefined number of preconditioning cycles are performed and the measurement system has been started according to the requirements of point 7.3.1.4. The amount of preconditioning shall be identified by the engine manufacturer before starting to precondition. Preconditioning shall be performed as follows, noting that the specific cycles for preconditioning are the same ones that apply for emission testing.
Engines fitted with an after-treatment system may be operated prior to cycle-specific preconditioning set out in points 7.3.1.1.1 to 7.3.1.1.4, so that the after-treatment system is regenerated and, where applicable, the soot load in the particulate after-treatment system is re-established.

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Source: https://www.legislation.gov.uk/eur/2017/654/annex/VI/division/7/division/7.3/division/7.3.1/division/7.3.1.1 (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-654/annex-VI/division-7/division-7.3/division-7.3.1/division-7.3.1.1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.