The international Atomic Energy Agency
(IAEA) has several coordinated research
programmes in which the participants are
to collect and analyze samples of the ambient
aerosol. In order to have comparable
samples taken in the variety of locations
around the world, the IAEA contracted
with the University of Gent to design and
construct a sampler that would generally
follow the requirements of a PMlO sampler.
The sampler design is described by Maenhaut
et al. (1993).
The sampling head for the unit is shown
in Fig. 1. The air enters the unit through an
impactor stage designed to have a 50%
collection efficiency at 10 /Lm equivalent
aerodynamic diameter. It then is drawn
through a stacked-filter unit (SFU). The
SFU consists of.. a holder for two sequential
filters construc'ted by the Norwegian Institute
for Air Research (NILU). The initial
filter is an 8 /Lm pore 47 mm Nuclepore@
filter and the second filter is an 0.4 /Lm
pore Nuclepore@ filter. At a flow rate of 16
lpm, the unit should act as a dichotomous
sampler. The flow through the 8 /Lm pores
will result in collection of ~ 2.2 /Lm particles
with 50% efficiency (Cahill et aI., 1979).
The < 2.2 /Lm particules are then collected
on the 0.4 /Lm filter (Cahill et aI., 1979).
The complete unit design is shown in Fig. 2.
FIGURE