CORRECTING PM10 OVER-SAMPLING PROBLEMS FOR AGRICULTURAL PARTICULATE MATTER EMISSIONS: PRELIMINARY STUDY

Abstract

The Federal Reference Method (FRM) ambient PM10 sampler does not always measure the true PM10concentration. There are inherent sampling errors associated with the PM10 samplers due to the interaction of particle sizedistribution (PSD) and sampler performance characteristics. These sampling errors, which are the relative differencesbetween theoretical estimation of the sampler concentration and the true concentration, should be corrected for equalregulation between industries. An alternative method to determine true PM10 concentration is to use the total suspendedparticulate (TSP) concentration and PM10 fraction of the PSD in question. This article reports a new theoretical method tocorrect PM10 sampling errors for a true PM10/TSP ratio. The new method uses co-located PM10/TSP samplers measurementsto derive the mass median diameter (MMD) of PSD and true PM10/TSP ratio. Correction equations and charts have beendeveloped for the PMs with GSDs of 1.2, 1.3, ..., 2.1, respectively, and the PM10 sampler with a cutpoint of 10 .m and slopeof 1.5. These equations and charts can be used to obtain a corrected PM10/TSP ratio for the given GSD and samplercharacteristics. The corrected PM10/TSP ratio will be treated as the true PM10/TSP ratio for PM10 concentrationcalculations. This theoretical process to obtain a corrected PM10/TSP ratio will minimize the inherent PM10 sampler errorsand will provide more accurate PM10 measurement for the given conditions.