A new inertial and diffusional device (SDI 2000)

Our aim has been to develop a new diffusional and Inertial Spectrometer (SDI 2000) able to cover a 2000-fold size range from 0.0075 μm to 15 μm and also to provide a mass size distribution corresponding to the true aerodynamic behavior of the aerosol measured. For this we chose to characterize aerosol inertial behavior for sizes sizes greater than 0.3 μm and aerosol diffusional behavior for sizes less than 0.3 μm. To achieve this, we combined in series a cascade impactor and a diffusion battery consisting of tubes arranged in parallel. The first step in analyzing mass size distribution of an aerosol involves inertial selection by collecting deposits at different stages of the impactor. The second step is a diffusional selection performed by collecting the deposits on filters placed downstream from the tubes where the aerosol is diffused through beds of glass beads