# 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 3.2.1.2: Calculation of the NOx humidity correction factor


In order to correct the influence of humidity on the results of oxides of nitrogen, the following calculations apply:
KH=11− 0,0329×H− 10,71where:
H=6,211× Ra× PdPB− Pd× Ra× 10− 2and:
His the specific humidity, grams of water vapour per kilogram dry air;
Rais the relative humidity of the ambient air, per cent;
Pdis the saturation vapour pressure at ambient temperature, kPa;
PBis the atmospheric pressure in the room, kPa.
The KH factor shall be calculated for each phase of the test cycle.
The ambient temperature and relative humidity shall be defined as the arithmetic average of the continuously measured values during each phase.

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Source: https://www.legislation.gov.uk/eur/2017/1151/annex/Sub/7/division/division/3./division/3.2./division/3.2.1./division/3.2.1.2. (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-1151/annex-Sub/7/division/division-3./division-3.2./division-3.2.1./division-3.2.1.2.
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.