Gerhard Göbel, Thomas Wriedt, and Klaus Bauckhage
Micron and submicron aerosol sizing with a standard phase-Doppler anemometer
submited for publication in J. Aerosol Sci. (1997).
Abstract:
In this paper the extended application range of
the standard phase-Doppler anemometer (PDA) to particle diameters below the
commonly accepted lower limit of about 5 to 10µm is described. The problems
that accompany measurements on smaller particles are small scattering
crossections and ambiguous relations between the measured phase difference
and the particle diameter.
A simple, but flexible optical setup for the
transmitting part of a standard PDA system, and a numerical algorithm,
which allows careful data evaluation from ambigouos phase-diameter relations,
help to manage these problems.
Measurements on aqueous suspensions of micron and sub-micron sized
dielectric and metalic monospheres, as well as on polydisperse aerosols,
are presented and evaluated by means of the proposed algorithm.
