Attenuation by artificial fogs in the visible, near infrared, and far infrared.
The attenuation coefficient ratio (alphalambda/alpha(o.546)) for artificial fogs has been measured at 345 micro, coefficient ratios at 0.436 micro, 1.01 micro, 3.5 micro, 10 micro, and 13.5 micro were also measured so that a comparison between artificial fogs and natural fogs could be made. By comparing our results with others on natural fogs and with the theoretical work of others in the visible and near ir, we have concluded that our artificial fogs closely resemble natural fogs. We conclude, therefore, that alpha(O.345)/alpha(o.546) is representative of real fogs. Artificial fogs are generated and allowed to dissipate during which time attenuation of light at several wavelengths is recorded. The green line of the mercury arc at 0.546 micro was used as the standard of comparison. For radiation at 345 micro,(alpha345/alphaO.546) = 0.014 +/- 0.009 during the generation time of the fog and 0.021 +/- 0.006 during the time the fog is allowed to dissipate.
Johnston
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Aeronutronic Division, Philco-Ford Corporation, Ford Road, Newport Beach, California 92663, USA.
Burch
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