The characterization of EPA's dry particle deposition chamber has been ongoing since the 1996 publication of EPA 600/R-96/106 'Development and Evaluation of a Dry Particle Deposition Uniformity System with Transverse (DUST) to Generate Test Surfaces for House Dust Sampler Characterization, Re-entrainment, and Resuspension Studies.' The current report details the changes to the mechanical configuration, the operating procedures, the algorithms for data analyses, and the overall capabilities of the system. The uniformity achieved across the chamber surface for particle of size 1 to 250 micron physical diameter was 10% +/- 5% relative standard deviation. The accuracy of the entire system, as determined using the 'worse case' scenario of 1-10 micrometer particles with a surface loading of 0.50 g/ sq m, was 21.6 +/- 12%. Additionally, a tagging procedure has been developed with the intended purpose of applying coatings of rare earth metals to discrete size fractions of surrogate dusts. Extracted metals from tagged particles may be analyzed by inductively coupled plasma mass spectrometry (ICP-MS) to determine particle fate and transport as a function of discrete particle size ranges. Due to sensitivity of ICP-MS, lower surface loadings of 0.1 g/sq m are now theoretically possible.

"Roy L. Bennett, project officer." "EPA/600/R-00/005." "November 1994." "S.L. Harper, task manager." Caption title. "February 7, 2000." "RTI Project No. 91U-7263-031." "EPA Contract 68-D5-0040." Microfiche.