# 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: Determination of PN


PN shall be calculated using the following equation:
PN=V×k×Cs–×fr–−Cb×frb–×103d
where:
PNis the particle number emission, particles per kilometre;
Vis the volume of the diluted exhaust gas in litres per test (after primary dilution only in the case of double dilution) and corrected to standard conditions (273,15 K (0 °C) and 101,325 kPa);
kis a calibration factor to correct the PNC measurements to the level of the reference instrument where this is not applied internally within the PNC. Where the calibration factor is applied internally within the PNC, the calibration factor shall be 1;
Cs–is the corrected particle number concentration from the diluted exhaust gas expressed as the arithmetic average number of particles per cubic centimetre from the emissions test including the full duration of the drive cycle. If the volumetric mean concentration results C– from the PNC are not measured at standard conditions (273,15 K (0 °C) and 101,325 kPa), the concentrations shall be corrected to those conditions Cs–;
Cbis either the dilution air or the dilution tunnel background particle number concentration, as permitted by the approval authority, in particles per cubic centimetre, corrected for coincidence and to standard conditions (273,15 K (0 °C) and 101,325 kPa);
fr–is the mean particle concentration reduction factor of the VPR at the dilution setting used for the test;
frb–is the mean particle concentration reduction factor of the VPR at the dilution setting used for the background measurement;
dis the distance driven corresponding to the applicable test cycle, km.
C–shall be calculated using the following equation:
C–=∑ni=1Cin
where:
Ciis a discrete measurement of particle number concentration in the diluted gas exhaust from the PNC; particles per cm3 and corrected for coincidence;
nis the total number of discrete particle number concentration measurements made during the applicable test cycle and shall be calculated using the following equation:
n = t × f
where:
tis the time duration of the applicable test cycle, s;
fis the data logging frequency of the particle counter, Hz.

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Source: https://www.legislation.gov.uk/eur/2017/1151/annex/Sub/7/division/division/4. (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-1151/annex-Sub/7/division/division-4.
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.