• T he s electively top o f PM-10 which i s t he a rea o f 10 μm fragmentation by direct impact. This direct impact is
based on the aerodynamic effect induced by the presence of 9 circular nozzles positioned above a smooth impaction
surface. Particles below the cutoff of 10μm are driven by the air flow through the nozzles and collected on the filter.
While larger particles deviate from the flow and impacting on the flat surface of impaction due to their higher
inertia. In order to avoid re-entrainment of coarse particles, the impact surface is greased by silicone oil and cleaned
regularly.
• The Anderson cascade impactors allows for a measure of particles by size distribution; it has four levels and offers
access to the 5 size classes: 10 to 7 μm, 7 to 3 μm, 3 to 1.5 μm, 1.5 to 1 μm and below 1 μm (Figure 2).
The flow rate was set at 1m3/min. The sampling time was 24 hours.