Tables 316 and 317 319 



SPECTRAL ENERGY DISTRIBUTION AND LUMINOSITY DATA (concluded) 



Factors proportional to the values of Table 315 adjusted so that the area of each complete curve of 

 minosity factors between 0.40 and 0.76M is equal to unity. To obtain the light transmission of a screen, 

 ultiply the spectrum transmission at each X by the corresponding tabulated or interpolated factor, 

 Gaining in each case an element of light transmission for the wave-length interval X — .oi^toX + .01 11. 

 he integral light transmission is obtained as the sum of these elements. The same process is followed 

 r spectrum reflection. 



TABLE 316. — Luminosity Factors 



TABLE 317.— Percentage Change in J for Change of ± 30 in Planck's C a (14330) 



Example: At color temperature 2300°K., the value below for 0.44/x is 0.8%, due to a change of 30 in 

 '2. For a change of 20 in C 2 the change in J 0A4 is ^ of 0.8 = 0.5%; for a change of 15 in C 2 , }4 of 0.8 

 = 0.4%, etc. 



Algebraic sign of tabulated values: 



Tabulated values 

 1st 6 col. Next 6 col. 



+ 



+ 



Change in C 2 — Increase 



Decrease 



In line "all X" are given values for adjustment of the percentage values above in Table 315 to obtain 

 he % change in the luminosity factors of Table 316. Each of these constants applies to all values given 

 bove it in the table; that is, one constant for each temperature. Combine the given constant by algebraic 

 ddition with the individual values at each wave length. 



Example: Color temp. 2600 K.;X = 0.52/x; C 2 changed from 14330 to 14310. At o.52m,26oo K., 0.3% 

 ; tabulated. Its sign is +, and C 2 is decreased. The corresponding constant in line "all X" is —0.07, the 

 linus sign corresponding to a decrease in C 2 . For a change of —30 in C 2 , the % change for Table 317 is 

 .3-0.1%. For the assigned change of —20 in C 2 , the required adjustment to the value in Table 316 is ^ 

 f 0.2 = 0.1%. At X = .71^, the adjustment would be JA, (-0.3 - 0.1) = - 0.2%, etc. 



MITHSONIAN TABLES 



