# 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 4.2.2.4: Buoyancy correction


The sample and reference filter weights shall be corrected for their buoyancy in air. The buoyancy correction is a function of sampling filter density, air density and the density of the balance calibration weight, and does not account for the buoyancy of the particulate matter itself.
If the density of the filter material is not known, the following densities shall be used:
(a)PTFE coated glass fibre filter: 2 300 kg/m3;
(b)PTFE membrane filter: 2 144 kg/m3;
(c)PTFE membrane filter with polymethylpentene support ring: 920 kg/m3.
For stainless steel calibration weights, a density of 8 000 kg/m3 shall be used. If the material of the calibration weight is different, its density shall be known and be used. International Recommendation OIML R 111-1 Edition 2004(E) (or equivalent) from International Organization of Legal Metrology on calibration weights should be followed.
The following equation shall be used:
mf=muncorr×1−ρaρw1−ρaρf
where:
Pefis the corrected particulate sample mass, mg;
Peuncorris the uncorrected particulate sample mass, mg;
ρais the density of the air, kg/m3;
ρwis the density of balance calibration weight, kg/m3;
ρfis the density of the particulate sampling filter, kg/m3.
The density of the air ρa shall be calculated using the following equation:
ρa=pb× MmixR× Ta
pbis the total atmospheric pressure, kPa;
Tais the air temperature in the balance environment, Kelvin (K);
Mmixis the molar mass of air in a balanced environment, 28,836 g mol–1;
Ris the molar gas constant, 8,3144 J mol–1 K–1.

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Source: https://www.legislation.gov.uk/eur/2017/1151/annex/Sub/5/division/division/4./division/4.2./division/4.2.2./division/4.2.2.4. (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-1151/annex-Sub/5/division/division-4./division-4.2./division-4.2.2./division-4.2.2.4.
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.