Evaluation of the particle measurement programme (PMP) protocol to remove the vehiclesʹ exhaust aerosol volatile phase Original Research Article

European regulation for Euro 5/6 light duty emissions introduced the measurement of non-volatile particles with diameter > 23 nm. The volatile phase is removed by using a heated dilution stage (150 °C) and a heated tube (at 300–400 °C). We investigated experimentally the removal efficiency for volatile species of the specific protocol by conducting measurements with two Euro 3 diesel light duty vehicles, a Euro 2 moped, and a Euro III heavy duty vehicle with the systemʹs heaters on and off. The particle number distributions were measured with a Scanning Mobility Particle Sizer (SMPS) and a Fast Mobility Particle Sizer (FMPS). An Aerosol Mass Spectrometer (AMS) was used to identify the non-refractory chemical composition of the particles. A Multi-Angle Absorption Photometer (MAAP) was used to measure the black carbon concentration. The results showed that the condensed material in the accumulation mode (defined here as particles in the diameter range of ∼ 50–500 nm) was removed with an efficiency of 50–90%. The (volatile) nucleation mode was also completely evaporated or was decreased to sizes < 23 nm; thus these particles wouldnʹt be counted from the particle counter, indicating the robustness of the protocol.