Device for the separation of airborne particles into grain size classes

A device is described for the separation of airborne particles, such as particles of an aerosol, into grain size classes. The main characteristic of the present invention lies in the fact that it comprises: a first body in which there is formed an L-shape channel defined by a first cavity from which, in use, filtered air is ejected into a second cavity thereof formed on the lower surface of the said first body; a second body having an upper surface in contact with the lower surface of the said first body; a third cavity formed in the said second body in correspondence with the said second cavity and in which there is created a depression; a rectangular plate the upper surface of which is flat and the edge of which is fixed by adhesive to the edge of the said third cavity for delimiting the said second cavity from below, there being formed a plurality of through slits in the said plate; and a nozzle operable to inject a quantity of aerosol into the said first cavity in proximity with the connection of this with the said second cavity.