You are here:
PERFORMANCE AND SENSITIVITY ANALYSIS OF THE USEPA WINS FRACTIONATOR FOR THE PM 2.5 FEDERAL REFERENCE METHOD
Citation:
Vanderpool, R. W., T. M. Peters, S. Natarajan, D B. Gemmill, AND R W. Wiener. PERFORMANCE AND SENSITIVITY ANALYSIS OF THE USEPA WINS FRACTIONATOR FOR THE PM 2.5 FEDERAL REFERENCE METHOD. Presented at PM 2000 AWMA Conference, Charleston, SC, January 25-28, 2000.
Impact/Purpose:
The overall objectives of this task are to provide reference methods and their associated EPA designation requirements for PM when new indicators of PM are required by OAQPS, and to provide continuous improvements to existing PM reference and equivalent methods so that national data quality objectives for PM can be met. These efforts will provide the necessary assurance that attainment determination uncertainties are at acceptable levels.
Description:
In response to growing health concerns related to atmospheric fine particles, EPA promulgated in 1997 a new particulate matter standard accompanied by new sampling methodology. Based on a review of pertinent literature, a new metric (PM;,) was adopted and its measurement method was specified as a 24 hour, integrated sample whose concentration was to be determined gravimetrically. The new method was developed as a hybrid of design and performance specifications. Components designed to representatively extract, size-select, and transport the PM^ aerosol (inlet, downtube, fractionator, and upper portion of the filter holder) were all specified by design with mechanical drawings published in the CFR. Accuracy and precision of flow control, ambient temperature and pressure measurement, and allowable sample overheat were all specified by performance. Accurate fractionation of aspirated atmospheric aerosol is a critical feature of the measurement method. In the FRM sampler, this fractionation is provided by a single-stage, single-jet impactor known as the WINS (Well Impactor Ninety-Six). Particles larger than 2.5 um aerodynamic diameter are efficiently collected on a glass fiber filter immersed in a low-volatility diffusion oil. Particles smaller than 2.5 um are transported to a teflon afterfilter for subsequent gravimetric measurement.
This work was funded by the U.S. EPA through its Office of Research and Development under contract #68-D5-0040 to Research Triangle Institute. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.