Record Display for the EPA National Library Catalog

RECORD NUMBER: 453 OF 833

OLS Field Name OLS Field Data
Main Title Investigation of particulate matter monitoring using contact electricity : final report /
Author John, Walter. ; Reischl, Georg ; Devor, William ; Wesolowski, Jerome J.
Other Authors
Author Title of a Work
John, Walter.
Nader, John.
CORP Author California State Dept. of Health, Berkeley. Air and Industrial Hygiene Lab.;Environmental Sciences Research Lab., Research Triangle Park, NC.
Publisher U.S. Environmental Protection Agency, Environmental Sciences Research Laboratory, Office of Research and Development,
Year Published 1978
Report Number EPA/600/2-78/212; EPA-R-803719-01-2
Stock Number PB-289 565
Additional Subjects Aerosols ; Surfaces ; Air pollution ; Monitors ; Electric charge ; Continuous sampling ; Impact ; Air pollution detection ; Contact electricity
Holdings
Library Call Number Additional Info Location Last
Modified
Checkout
Status
NTIS  PB-289 565 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 01/01/1988
Collation ix, 70 pages : illustrations ; 28 cm.
Abstract
To better understand the contact electrification monitor for particulate matter, charge transfer by aerosol particles impacting on metal surfaces has been investigated. Monodisperse, uniformly charged or neutral aerosol particles (1-5 micrometer diameter) from a vibrating orifice or fluidized bed generator were bounced on a metal probe. The transfer of precharge from the particles were found to be sensitive indicators of the probe surface condition. A surface preparation procedure was developed which yielded linear charge transfer curves. Measurements were made of methylene blue, potassium biphthalate, sodium chloride and aluminum particles impacting on stainless steel, Inconel, titanium and platinum probes. For insulating materials, the transfer of precharge was independent of particle size while the contact charge was proportional to the cube of particle diameter and directly proportional to impact velocity. The magnitude of the contact charge was strongly dependent on the electrical resistivity of the material. A theoretical model was found to account semi-quantitatively for all aspects of the data. A major remaining difficulty is the lack of knowledge of the contact potential. The implications of these findings for monitoring applications is discussed in detail and the advantages and disadvantages of the monitor are assessed.
Notes
Project Officer: John Nader. California Department of Health Services, Air and Industrial Hygiene Laboratory Section "October 1978." Includes bibliographical references. "EPA-600/2-78-212." Microfiche.