“…It is used to fractionate very small aerosol fineparticles of Stokes diameter of 0.015-2.0 microns [22]. The cross-flow classifier shown in Figure 5.10, developed by various investigators, is an industrial-scale horizontal elutriator [24,25,26]. The aerosol is initially drawn into an ionization chamber in which the ionization conditions are controlled so that the fineparticles of the aerosol are charged in such a way that the electrical mobility of the fineparticle is proportional to its size.…”