This report describes the 2020 assessment of the margins for the RDE (Real-Driving Emissions) results prescribed in the EURO 6 regulation. Margin is defined as the additional measurement uncertainty introduced by PEMS (Portable Emissions Measurement Systems) compared to the laboratory systems for a pollutant. The 2020 data collected by a series of EU testing houses showed in general very good performance of the PEMS in terms of NOx zero drift and laboratory validation results. In consequence, the framework to calculate the NOx margin was modified and together with the observed improvement of the exhaust flow meter’s uncertainty, the NOx margin may now be decreased from 0.32 to 0.23. In practical terms, this value covers at least 95% of the worst cases, compared to the 99% of the previous report.
The data suggest that further reduction is possible by improving the permissible tolerances for the equipment in the regulation and the method by which the zero drift is taken into account. Under this future scenario the future NOx margin could be reduced to 0.10, but this requires first changes in the regulation.
In this report, the framework was further developed to analyse the Particle Number (PN) margin. Based on the analysis of this report the PN margin is now estimated to be 34% (0.34).
For further reductions of the PN margin a more holistic approach is necessary (e.g. bringing closer technical and calibration specifications of the PN-PEMS and the reference PMP systems).
GIECHASKIEL Barouch;
VALVERDE MORALES Victor;
CLAIROTTE Michael;
Giechaskiel, B., Valverde Morales, V. and Clairotte, M., Real Driving Emissions (RDE): 2020 assessment of Portable Emissions Measurement Systems (PEMS) measurement uncertainty, EUR 30591 EN, Publications Office of the European Union, Luxembourg, 2021, ISBN 978-92-76-30230-8, doi:10.2760/440720, JRC124017.
2021-02-22
Publications Office of the European Union
JRC124017
978-92-76-30230-8 (online),
1831-9424 (online),
EUR 30591 EN,
OP KJ-NA-30591-EN-N (online),
https://publications.jrc.ec.europa.eu/repository/handle/JRC124017,
10.2760/440720 (online),
