Testing particle mass (PM), number (PN) and particle size distribution

Measurements of the mass of particulates (PM) emitted on the chassis dyno are carried out using the gravimetric method and a partial-dilution CVS tunnel. The particulate accumulated on the filters is weighed using a microbalance, which allows measurements of particles emitted by engines complying with the Euro 6 standard. The latest exhaust emission limits also specify the maximum number of particles (PN) that is allowed in individual approval tests. Particle number can be measured both in undiluted and diluted exhaust gas. For a more detailed analysis of the composition of the particles emitted by the engine, it is possible to measure the particle size distribution using a spectrometer.