)
or number concentration (number of particles
);
modern instrumentation allows measurement of the number of particles as a function of size as well as the total number present in a given air volume. For atmospheric aerosols, this is a complex distribution for which diameters range from below
to above
;
the particles making the highest contribution to the total number density are in the size range below
,
those contributing most to the total surface area are in the
to
range, while those with the highest contribution to the volume or mass of the aerosol come from both the
to
and
to
ranges. Source:
PAC, 1990, 62, 2167
(Glossary of atmospheric chemistry terms (Recommendations 1990))
on page 2181