Method and device for determining particle size distribution in aerosol

To increase the dynamic range when testing the particle size distribution of aerosols, the invention proposes a method whereby particles are detected in two measuring volumes connected in series in the measuring channel, whereby in particular the total number of particles flowing through the measuring channel passes through one measuring volume while only a smaller number of particles passes through the other measuring volume. A device appropriate therefor provides for a first measuring volume (MV1) to be located immediately downstream of an inlet nozzle (4) for the aerosol and having a surface perpendicular to the flow direction of the aerosol, said surface corresponding to the surface of the end of the inlet nozzle and for a second measuring volume to be provided downstream of the first measuring volume at a distance therefrom, the cross section of said second measuring volume perpendicular to the flow direction of the aerosol being smaller than the cross section of the measuring channel.