||High-Volume Impactor for Sampling Fine and Coarse Particles.
Marple, V. A. ;
Liu, B. Y. H. ;
Burton., R. M. ;
||Environmental Protection Agency, Research Triangle Park, NC. Atmospheric Research and Exposure Assessment Lab. ;Minnesota Univ., Minneapolis. Particle Technology Lab.
Air samplers ;
Particle size ;
Air pollution monitors ;
Field tests ;
||Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy.
Final design, calibration, and field testing have been completed for a new 1.13 cu m/min (40 cfm) High-Volume Virtual Impactor (HVVI). Field tests have demonstrated that the new classifier/collector works well as an accessory to the existing PM(sub 10). Size Selective Inlet high-volume samplers. The HVVI provides two fractions of PM(sub 10) mass, both of which are collected by filtration. The fine fraction (0-2.5 micrometer aero. dia.) is collected on the standard 20.3 x 25.4 cm (8-x 10-in) high-volume filter; the coarse fraction (2.5-10 micrometer aero. dia.) is collected on a 5.1 x 15.2 cm (2- x 6-in) filter. Coarse flow through the receiver tubes is limited to 0.166 cu m/min (2 cfm), 5% of the total flow. The operating pressure drop across the HVVI stages is sufficiently high to make changes in pressure across the collection filters insignificant. The HVVI filter holder assembly facilitates loading/unloading samples in the laboratory, thus eliminating damage due to handling filters in the field. Size separation characteristics of the HVVI agree well with those for the 16.7 L/min commercially available dichotomous sampler with the 50% effectiveness (cut-point) occurring at 2.5 micrometer. (Copyright (c) 1990--Air and Waste Management Association.)