ABSTRACT

The FRM ambient PM₁₀ sampler does not always measure the true PM₁₀ concentration. There are inherent sampling errors associated with the PM₁₀ samplers due to the interaction of particle size distribution and sampler performance characteristics. These sampling errors, which are the relative differences between theoretical estimation of the sampler concentration and the true concentration, should be corrected for equal regulation between industries. An alterative method of determines true PM₁₀ concentration is to use the TSP concentration and PM₁₀ fraction of PSD in question.

This paper reports a new theoretical method to correct PM₁₀ sampling errors for a true PM₁₀/TSP ratio. The new method uses co-located PM₁₀/TSP samplers’ measurement to derive the MMD of PSD and true PM₁₀/TSP ratio. Correction equations and charts have been developed for the PM's with GSD's of 1.2, 1.3, ... 2.1, respectively and the PM₁₀ sampler with a cut-point of 10 µm and slope of 1.5. These equations and charts can be used to obtain a corrected PM₁₀/TSP ratio for the given GSD and sampler characteristics. The corrected PM₁₀/TSP ratio will be treated as true PM₁₀/TSP ratio for PM₁₀ concentration calculations. This theoretical process to obtain a corrected PM₁₀/TSP ratio will minimize the inherent PM₁₀ sampler errors and will provide more accurate PM₁₀ measurement for the given condition.