File:Daylight efficiency of artificial illuminants (1909) (14774145251).jpg

Identifier: dayl62312461909125125unse (find matches)
Title: Daylight efficiency of artificial illuminants
Year: 1909 (1900s)
Authors:
Subjects: photometry lamps and lighting
Publisher: National Bureau of Standards
Contributing Library: NIST Research Library
Digitizing Sponsor: NIST Research Library

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Text Appearing After Image:
.42 .5 .6 Jft Fig.l.—Curves Showing Amount of Spectra of Various Light Sources whichmur.t be A hsorbed to Leave White Light. 236 Bulletin of the Bureau of Standards. Woi. 6, No. 2. this point, the deficiency in blue sensation of any of the ordinarysources is less than 2 per cent, a quantity small enough to beconsidered negligible. A different choice of equality point will ofcourse lead to numerically different results, a matter to be treatedagain in the discussion of the second method. In Fig. I the data of Table II are plotted on this basis. Thearea of each curve above the shaded area represents the por-tion of the illuminants spectrum which must be removed byabsorption to reduce it to identity with the daylight spectrum.The colored glass to effect this is one whose transmission is thereciprocal of the ordinate of the curve in question at each point. Having obtained the properly colored glass to effect the absorp-tion, we now wish to know the intensity value of the resultantartific

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