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Description:
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Currently , a lack of accurate emission data exits for particulate matter (PM ) in
agricultural air quality studies (USDA -AAQTF , 2000 ) . PM samplers , however , tend to
over estimate the concentration of most agricultural dusts because of the interaction of
the particle size distribution (PSD ) and performance characteristics of the sampler
(Buser , 2004 ) . This research attempts to find a practical method to characterize and
correct this error for the Federal Reference Method (FRM ) PM10 sampler . First , a new
dust wind tunnel testing facility that satisfies the USEPA’s requirement of testing PM10
samplers was designed , built , and evaluated . Second , the wind tunnel testing protocol
using poly -dispersed aerosol as the test dust was proved to be able to provide results
consistent with mono -dispersed dusts . Third , this study quantified the variation of over
sampling ratios for the various cut point and slopes of FRM PM10 samplers and proposed
an averaged over sampling ratio as a correction factor for various ranges of PSD . Finally ,
a method of using total suspended particle (TSP ) samplers as a field reference for
determining PM10 concentrations and aerosol PSD was explored computationally . Overall , this dissertation developed successfully the methodology to correct the
sampling error associated with the FRM PM10 sampler : (1 ) wind tunnel testing facilities
and protocol for experimental evaluation of samplers ; (2 ) the variation of the oversampling
ratios of FRM PM10 samplers for computational evaluation of samplers ; (3 ) the
evaluation of TSP sampler effectiveness as a potential field reference for field evaluation
of samplers . |