The European Directive introducing Euro5/Euro6 incorporates measurements of the number of particles. In this context, UTAC has been studying the feasibility of these measures since 2000 using an ELPI Dekati impactor.

 In 2007 we studied particles size distribution (size and number) according to :

• Different engine technologies
• Device Particle filters (DPF)
• Bio-fuels

The tests were performed according to the European cycle on a chassis dynamometer with a cold start.

The measurement results are shown in the following graph. The number of particles emitted is expressed according to the diameter of the particles measured.

 The following phenomena can be observed :

• Effects of engine technologies (direct petrol and diesel injection),
• Efficiency of the device particle filter in relation to the number of particles emitted
• Effects of the use of bio-fuels (petrol with ethanol and diesel with rape diester).