Record Display for the EPA National Library Catalog


OLS Field Name OLS Field Data
Main Title Comparison of Telephotometer Measurements of Extinction Coefficients with Scattering and Absorption Coefficients.
Author Dzubay, T. G. ; Clubb, K. W. ;
CORP Author Environmental Sciences Research Lab., Research Triangle Park, NC.
Year Published 1981
Report Number EPA-600/J-81-015;
Stock Number PB82-205881
Additional Subjects Light transmission ; Light scattering ; Visibility ; Sulfates ; Air pollution ; Reprints ; Extinction coefficients ; Atmospheric transmissivity ; Telephotometry ; Air quality
Library Call Number Additional Info Location Last
NTIS  PB82-205881 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. 06/23/1988
Collation 11p
During the summer of 1979, coefficients for light extinction in the atmosphere were calculated from measurements made with a telephotometer placed 251 m from a black target in Research Triangle Park, North Carolina. The results are well correlated (r = 0.92 to 0.96) with integrating nephelometer measurements of scattering coefficients and are highly correlated (r = 0.99) with daily averages of sums of scattering and absorption coefficients. The average sum of scattering and absorption coefficients accounts for about 90% of the average telephotometrically measured extinction coefficient; absorption by particles and nitrogen dioxide contributes 7% and 2%, respectively. From analysis of aerosol mass and composition, it is inferred that sulfate and its cations were the major cause of light extinction and haze at the measurement site.