An Innovative Sampler as a Reference Standard for Measurement of Particulate Matter Mass in Ambient Air

Particulate matter (PM) in ambient air is comprised of many chemical species of varying vapor pressures. A direct-mass measurement of PM mass on filters is the basis of regulatory PM reference methods. The loss of semivolatile PM mass collected on filters and filter sampling artifacts can produce nonquantifiable biases in reference method measurements depending on the thermodynamic history of the filter; therefore, a reference method cannot be considered a scientific reference standard. Rupprecht & Patashnick, Co., Inc. (R&P) has developed a new technique that has the potential to overcome the difficulties inherent in PM mass measurement and holds the promise of the measurement of PM mass as it exists in ambient air at ambient temperature. The Differential TEOM¿ System has the potential to become a new reference standard for determining the particulate matter mass in ambient air. As part of this Phase I project, R&P intends to build two prototype samplers for initial field studies. These field studies will be used to identify thermal areas that need further review and to determine if any of the components require significant design modifications prior to the final commercialization of the measurement concept.