A system is disclosed for condensation particle counting in conjunction
with modifying an aerosol to enhance the formation and growth of droplets
of a selected working fluid, preferably water. Before saturation with the
working fluid, the aerosol is exposed to an aerosol modifying component,
preferably a vapor including molecules that are adsorbed onto surfaces of
the particles or other elements suspended in the aerosol. Adsorption
alters the surface character of the suspended elements towards increased
affinity for the vapor of the working fluid, to promote the formation and
growth of working fluid droplets. The droplets are optically detected to
indicate numbers and concentrations of the suspended elements.