Journal article
Laboratory and field evaluation of crystallized DOW 704 oil on the performance of the Well Impactor Ninety-Six fFine particulate matter fractionator
Journal of the Air & Waste Management Association (1995), Vol.57(1), pp.14-30
01/2007
DOI: 10.1080/10473289.2007.10465299
PMID: 17269226
Abstract
Subsequent to the 1997 promulgation of the Federal Reference Method (FRM) for monitoring fine particulate matter (PM2.5) in ambient air, U.S. Environmental Protection Agency (EPA) received reports that the DOW 704 diffusion oil used in the method's Well Impactor Ninety-Six (WINS) fractionator would occasionally crystallize during field use, particularly under wintertime conditions. Although the frequency of occurrence on a nationwide basis was low, uncertainties existed as to whether crystallization of the DOW 704 oil may adversely affect a sampling event's data quality. In response to these concerns, EPA and the State of Connecticut Department of Environmental Protection jointly conducted a series of specialized tests to determine whether crystallized oil adversely affected the performance of the WINS fractionator. In the laboratory, an experimental setup used dry ice to artificially induce crystallization of the diffusion oil under controlled conditions. Using primary polystyrene latex calibration aerosols, standard size-selective performance tests of the WINS fractionator showed that neither the position nor the shape of the WINS particle size fractionation curve was substantially influenced by the crystallization of the DOW 704 oil. No large particle bounce from the crystallized impaction surface was observed. During wintertime field tests, crystallization of the DOW 704 oil did not adversely affect measured PM2.5 concentrations. Regression of measurements with crystallized DOW 704 versus liquid dioctyl sebacate (DOS) oil produced slope, intercept, and R2 values of 0.98, 0.1, and 0.997 microg/m3, respectively. Additional field tests validated the use of DOS as an effective impaction substrate. As a result of these laboratory and field tests, DOS oil has been approved by EPA as a substitute for DOW 704 oil. Since the field deployment of DOS oil in 2001, users of this alternative oil have not reported any operational problems associated with its use in the PM2.5 FRM. Limited field evaluation of the BGI very sharp cut cyclone indicates that it provides a viable alternative to the WINS fractionator.
Details
- Title: Subtitle
- Laboratory and field evaluation of crystallized DOW 704 oil on the performance of the Well Impactor Ninety-Six fFine particulate matter fractionator
- Creators
- Robert W Vanderpool - U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA. vanderpool.robert@epa.govLee A ByrdRussell W WienerElizabeth T HunikeMichael LabickasAlan R LestonMichael P TolockaFrank F McElroyRobert W MurdochSanjay NatarajanChristopher A NobleThomas M Peters
- Resource Type
- Journal article
- Publication Details
- Journal of the Air & Waste Management Association (1995), Vol.57(1), pp.14-30
- DOI
- 10.1080/10473289.2007.10465299
- PMID
- 17269226
- NLM abbreviation
- J Air Waste Manag Assoc
- ISSN
- 1096-2247
- eISSN
- 2162-2906
- Publisher
- United States
- Language
- English
- Date published
- 01/2007
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Occupational and Environmental Health
- Record Identifier
- 9983997332502771
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