Record Display for the EPA National Library Catalog


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 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
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.