1. TUG Roadside Measurements of Particulate Matter (PM) size distribution P.J. Sturm, S. Hausberger Graz University of Technology: Michael Bacher, Bernhard Lechner, Bernhard Heiden Paul Scherrer Institute: Urs Baltensperger, David Imhof, Ernest Weingartner, Andre S.H. Prevot Bergische Universität Wuppertal: Ralf Kurtenbach, Peter Wiesen TRL: Ian McCrae, Paul Boulter

2. TUG Institute for Internal Combustion Engines and Thermodynamics Graz University of Technology Measurement Programme  Roadside measurements were performed with the intention to document the size distribution of PM under dilution conditions similar to those found in real world  Measurements at:  engine test beds  at different locations in a road tunnel  at different locations in urban environment

3. TUG Institute for Internal Combustion Engines and Thermodynamics Graz University of Technology Engine measurements Euro 3, HDV Sampling according to “Particulates“ procedure

4. TUG Institute for Internal Combustion Engines and Thermodynamics Graz University of Technology City Bus

5. TUG Institute for Internal Combustion Engines and Thermodynamics Graz University of Technology Tunnel measurements Site 1: Inlet Site 4: Outlet Site 2: Roadside Site 3: Ventilation shaft

6. TUG Institute for Internal Combustion Engines and Thermodynamics Graz University of Technology Tunnel measurements Ambient air (site 1) Kerb side (site 2) Ventilation shaft (site 3) Ventilation outlet (site 4)

7. TUG Institute for Internal Combustion Engines and Thermodynamics Graz University of Technology Tunnel measurements – kerb side

8. TUG Institute for Internal Combustion Engines and Thermodynamics Graz University of Technology Tunnel measurements – ventilation outlet

9. TUG Institute for Internal Combustion Engines and Thermodynamics Graz University of Technology Tunnel measurements –Principal Component Analyses (PCA) The PCA tries to explain data as a combination of influencing factors, i.e. the principal components (PC), and weighing factors (t), which describe the individual weight of each of these PCs. PC1 looks like median of data With PC1 and PC 2 80% of all data can be described

10. TUG Institute for Internal Combustion Engines and Thermodynamics Graz University of Technology Tunnel measurements – first PC

11. TUG Institute for Internal Combustion Engines and Thermodynamics Graz University of Technology Tunnel measurements – second PC

12. TUG Institute for Internal Combustion Engines and Thermodynamics Graz University of Technology Tunnel measurements – factors for site 4

13. TUG Institute for Internal Combustion Engines and Thermodynamics Graz University of Technology Urban air measurements – kerb side

14. TUG Institute for Internal Combustion Engines and Thermodynamics Graz University of Technology Urban air measurements – urban background

15. TUG Institute for Internal Combustion Engines and Thermodynamics Graz University of Technology Conclusions  The engine measurements show a size distribution strongly dependent on engine load  At higher loads main peak in the 80 - 100 nm range  The kerb-side measurements in the tunnel show an aerosol size distribution strongly varying with the traffic volume  Depending on the traffic and ventilation situation nucleation mode particles or soot mode particles dominate. Main peak in the 80 – 100 nm range

16. TUG Institute for Internal Combustion Engines and Thermodynamics Graz University of Technology Conclusions - 2  The kerb side measurements at an intersection show a distribution having a peak at 25 nm, along with smaller nucleation particles around 10 nm  The pure soot mode (80 nm range) which is present in the engine and the tunnel measurements is hardly visible in this case  Measurements in the urban background show that almost no nucleation mode particles are present in the urban background  The mode of the size distribution is slightly shifted towards larger particles, the maximum is the 25 to 35 nm range

17. TUG Institute for Internal Combustion Engines and Thermodynamics Graz University of Technology Conclusions - 3  Tunnel measurements offer the possibility of investigating emissions from a huge variety of road vehicles. They are thus an optimal means for investigating real world emission behaviour  Contrary to gaseous pollutants, the PM size concentration due to emissions is influenced by the size distribution that is already present in the tunnel.  Particle number size distribution profiles recorded in street tunnels do not necessarily represent situations occurring in ambient air