Large Particle Penetration During PM10 Sampling
Abstract
The objective of the present study was to characterize the
performance of a federal reference method (FRM) PM
10
size-
selective inlet using analysis methods designed to minimize
uncertainty in measured sampling efficiencies for large particles
such as those most often emitted from agricultural operations.
The performance of an FRM PM
10
inlet was characterized in a
wind tunnel at a wind speed of 8 km/h. Data were also collected
for 20 and 25
m
m particles at wind speeds of 2 and 24 km/h.
Results of the present sampler evaluation compared well with
those of previous studies for a similar inlet near the cutpoint, and
the sampler passed the criteria required for certification as a
FRM sampler when tested at 8 km/h. Sampling effectiveness
values for particles with nominal diameters of 20 and 25
m
m
exceeded 3% for 8 and 24 km/h wind speeds in the present study
and were statistically higher than both the “ideal” PM
10
sampler
(as defined in 40 CFR 53) and the ISO (1995) standard definition
of thoracic particles (
p
<
0.05) for 25
m
m particles leading to the
potential for significant sampling bias relative to the “ideal”
PM
10
sampler when measuring large aerosols.