A methodology for determining the effects of fuels and additives on atmospheric visibility has been developed using the smog chamber approach. The methodology involves measuring visibility in a 590 cu m smog chamber after first introducing auto exhaust at a 300:1 detection ratio adding 0.05 ppm SO2 and irradiating the sample for 23 hours. Three 5.7 liter 1972 Chevrolets and one 1973 catalyst-equipped 6.55 liter Ford Galaxie were used in the study. The effects on test results of exhaust dilution ratio, relative humidity, added SO2, primary particulates, evaporative emissions and irradiation time are discussed. The tests show that using commercial grade indolene fuel, the effects on visibility of the additives F-310 and CI-2 are small compared to the effects brought about by variations in engine performance. The presence of primary particulates play an important role in the initial and final visibility noted in the smog chamber. The final visibilities noted in the smog chamber were found to be closely correlated with the initial HC/NO ratio. The correlation for the commercial grade indolene is so good that final visibilities can be predicted from the initial measurement of HC and NO in the chamber. For the fuels and additives tested at a given HC/NO ratio, the sulfur content of the fuel appeared to have the most important effect on visibility.

  • Corporate Authors:

    Calspan Corporation

    4455 Genesee Street
    Buffalo, NY  United States  14225

    National Environmental Research Center

    Chemistry and Physics Laboratory
    Res Triangle Park, NC  United States 
  • Authors:
    • Kocmond, W C
    • Yang, J Y
    • Davis, J A
  • Publication Date: 1975-6

Media Info

  • Pagination: 57 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00093684
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: CALSPAN-NA-5300-M-1 Final Rpt., EPA/650/2-75/068
  • Contract Numbers: EPA-68-02-0698
  • Files: TRIS
  • Created Date: Feb 4 1976 12:00AM