# Commission Regulation (EU) 2017/1151 of 1 June 2017 supplementing Regulation (EC) No 715/2007 of the European Parliament and of the Council on type-approval of motor vehicles with respect to emissions from light passenger and commercial vehicles (Euro 5 and Euro 6) and on access to vehicle repair and maintenance information, amending Directive 2007/46/EC of the European Parliament and of the Council, Commission Regulation (EC) No 692/2008 and Commission Regulation (EU) No 1230/2012 and repealing Commission Regulation (EC) No 692/2008 (Text with EEA relevance), Division 4.4.3.2: Measurement precision


The measurements shall be carried out in opposite directions until a minimum of three pairs of measurements at each reference speed vi have been obtained, for which Cj– satisfies the precision ρj according to the following equation:
ρj=h× sn×Cj–≤0.03where:
nis the number pairs of measurements for Cjm;
Cj–is the running resistance at the speed vj, Nm, given by the equation:
C–j=1n∑ni= 1Cjmi
where:
Cjmiis the arithmetic average torque of the ith pair of measurements at speed vj, Nm, and given by:
Cjmi=12×Cjmai+ Cjmbi
where:
Cjmai and Cjmbi are the arithmetic average torques of the ith measurement at speed vj determined in paragraph 4.4.3.1. of this Sub-Annex for each direction, a and b respectively, Nm;
sis the standard deviation, Nm, calculated using the following equation:
s=1k− 1∑ki= 1Cjmi−Cj–2;
his a coefficient as a function of n as given in Table A4/4 in paragraph 4.3.1.4.2. of this Sub-Annex.

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Source: https://www.legislation.gov.uk/eur/2017/1151/annex/Sub/4/division/division/4./division/4.4./division/4.4.3./division/4.4.3.2. (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-1151/annex-Sub/4/division/division-4./division-4.4./division-4.4.3./division-4.4.3.2.
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.