EMRP-ENV02: Emerging Requirements for Measuring Pollutants from Automotive Exhaust Emissions

• Forschungsstelle: METAS
• Projektnummer: F-5235.30003
• Projekttitel Englisch: EMRP-ENV02: Emerging Requirements for Measuring Pollutants from Automotive Exhaust Emissions

Schlüsselwörter (Englisch)

Particle number concentration, calibration, diesel engine, exhaust, Euro 5, Euro 6, Euro VI

Kurzbeschreibung (Englisch)

The Project EMRP ENV02-PartEmission will establish a sound metrological base for particle emissions in exhaust gases of diesel vehicles in Europe. This includes establishment of a particle number concentration standard for soot particles with the aim of providing calibration services for end users and industry, in particular for the calibration of measuring instruments for the type approval of Euro 5 and Euro 6 diesel vehicles such as light vans and passenger cars.
Furthermore, a sound background for metrological validation of novel instrument types measuring the soot particle concentrations in exhaust gases from diesel vehicles and their capability to be used for the regulatory periodic emission control of vehicles will be developed.

This project is part of the European Metrology Research Programme (EMRP, http://www.euramet.org/index.php?id=emrp); it is partly funded by the European Union on the basis of Decision No 912/2009/EC.

Projektziele (Englisch)

The aim of this project is to establish an international standard and a measurement service by NMIs for the calibration of condensation particle counters (CPCs). According to regulations ECE R83 and R49 for vehicle homologation, the particle number concentration measurements in diesel exhaust must be performed at certified particle mobility diameters between 23 nm and 100 nm and at certified number concentrations up to 10⁴ cm^-3.

Particle diameters of 50 nm and 100 nm are required for the number concentration calibration of the entire measuring system according to ECE that is the system with a volatile particle remover (VPR), an aerosol diluter and a specific CPC. Therefore, this aerosol must be thermally stable for temperatures up to 300 °C. The project aims to develop protocols for the aerosol stabilisation and for the calibration of particle number concentration.

Particle diameters of 23 nm and 41 nm are used to measure the material dependent cut-off curve of the CPC detection efficiency. The cut-off curve is a key parameter for the number concentration measurement in diesel exhaust since smallest particles contribute significantly to the total particle emission. This project will focus on most adequate aerosol generation principles for the ECE regulations and the traceability for the CPC efficiency evaluation.

Abstract (Englisch)

In the work package “Automotive combustion metrics“, coordinated by METAS, it has built up core competencies for the calibration of particle number measuring instruments for type testing of EURO 5b, EURO 6 und EURO VI vehicles.

• After successful aerosolisation of nanoscale reference materials with electrospray, it could be shown, that the electrical mobility diameter clearly deviates from the geometric diameter below 100 nm. Together with the project partners a recommendation for comparable adjustment of differential mobility analyser was issued.
• With a commercial thermodenuder CAST-Aerosol can be thermally stabilised and is thus appropriate to calibrate VPRs (Volatile Particle Removers).
• Together with the partners it was demonstrated, that the efficiency curve of condensation particle counters is strongly dependent on the aerosol type as well as on the engine operating conditions for “real-soot”. Thus no “soot-like” calibration aerosol can be de-fined. METAS has shown that heterogeneous nucleated silver particles may be used as a primary calibration aerosol.
• The newly developed calibration capabilities in the size range 5 nm to 40 nm were successfully validated in two international comparisons (EURAMET 1244 and EURAMET 1282).

In the second work package "Evaluation of measuring methods for particle emission from modern diesel vehicles in periodic emission control"“, the existing capabilities for testing the newly regulated nanoparticle measuring instruments for exhaust engines (SR 941.242) were applied to six new prototype measuring instruments.

Umsetzung und Anwendungen (Englisch)

The developed core competences in work package “Automotive combustion metrics“ could be utilized as services to customers. The determination of the efficiency curve of condensation particle counters in the size range 10 nm to 100 nm will be provided as a standard service.
The results of the second work package "Evaluation of measuring methods for particle emission from modern diesel vehicles in periodic emission control" allowed the validation of the existing test infrastructure for nanoparticle measuring instruments for exhaust engines (SR 941.242). The test infrastructure was already used for preliminary investigations for costumers and a first type approval.

Publikationen / Ergebnisse (Englisch)

Felix Lüönd, Jürg Schlatter, Improved monodispersity of size selected aerosol particles with a new charging and selection scheme for tandem DMA setup, Journal of Aerosol Science 62, 2013, pp 40–55.

Simon Zihlmann, Felix Lüönd, Johanna K. Spiegel, Seeded growth of monodisperse and spherical silver nanoparticles, Journal of Aerosol Science 75, 2014, pp 81-93.

Richard Högström, Paul Quincey, Dimitris Sarantaridis, Felix Lüönd, Andreas Nowak, Francesco Riccobono, Thomas Tuch, Hiromu Sakurai, Miles Owen, Martti Heinonen, Jorma Keskinen and Jaakko Yli-Ojanperä, First comprehensive intercomparison of aerosol electrometers for particle sizes up to 200 nm and concentration range 1000 cm⁻³ to 17 000 cm⁻³, Metrologia 51, 2014, pp 293–303.

Hanspeter Andres, Felix Lüönd, Jürg Schlatter, Kevin Auderset, Anke Jordan-Gerkens, Andreas Nowak, Volker Ebert, Egbert Buhr, Tobias Klein, Thomas Tuch, Alfred Wiedensohler, Athanasios Mamakos, Francesco Riccobono, Kai Discherl, Richard Högström, Jaakko Yli-Ojanperä and Paul Quincey, Measuring soot particles from automotive exhaust emissions, EPJ Web of Conferences 77, 00020, 2014.