Method to evaluate TSP sampler's effectiveness as field reference

The interaction of Particle Size Distribution (PSD) with PM 10 sampler characteristics will cause serious over-sampling problems for most agricultural dusts. To quantify this error in the field, an accurate reference of aerosol PSD and PM 10 concentration is required. Past studies normally used Total Suspended Particle (TSP) samplers followed by the measurement of the PSD from TSP filter to estimate the PSD and PM 10 . However, studies have shown that the cut point of TSP samplers can shift between 13 and 60 microns, which can significantly affect estimation accuracy. In this paper, computer simulation was deployed to estimate the true PSD and PM 10 in the air by using those measured by a TSP sampler. For PM 10 , the use of TSP samplers for the field reference of PM 10 could be recommended since the estimated value was comparable to the true value when the TSP sampler's cut point is greater than 20 microns. A retrieval chart was generated to convert PSDs measured by a TSP sampler (with a fixed cut point) to true PSDs. To assess the effect of varying cut points of the TSP sampler on estimation of true PSD, another chart for the Coefficient of Variation (COV) among the estimated true PSD was produced. The COV chart mayprovide guidance of whether a TSP sampler is suitable for use as a field reference of aerosol PSD on a case-by-case basis.

Method to evaluate TSP sampler's effectiveness as field reference Conference Paper