# 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 6.1: Laboratory test conditions

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

The absolute temperature (T a) of the engine air at the inlet to the engine expressed in Kelvin, and the dry atmospheric pressure (p s), expressed in kPa shall be measured and the parameter f a shall be determined in accordance with the following provisions and by means of equation (6-5) or (6-6). If the atmospheric pressure is measured in a duct, negligible pressure losses shall be ensured between the atmosphere and the measurement location, and changes in the duct's static pressure resulting from the flow shall be accounted for. In multi-cylinder engines having distinct groups of intake manifolds, such as in a ‘V’ engine configuration, the average temperature of the distinct groups shall be taken. The parameter fa shall be reported with the test results.
Naturally aspirated and mechanically supercharged engines:
f a = 99 p s × T a 298 0,7
(6-5)
Turbocharged engines with or without cooling of the intake air:
f a = 99 p s 0,7 × T a 298 1,5
(6-6)

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Source: https://www.legislation.gov.uk/eur/2017/654/annex/VI/division/6/division/6.1 (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-654/annex-VI/division-6/division-6.1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.