546 



TABLE 567.— TRANSMISSION OF RADIATION THROUGH MOIST AIR (percent) 



The values of this table are of use for finding the transmission of energy through air contain- 

 ing a known amount of water vapor. An approximate value for the transmission may be had if 

 the amount of energy from the source between the wavelengths of the first column is multiplied 

 by the corresponding transmission coefficients of the subsequent columns. The values for the 

 wavelengths greater than 18/x are tentative and doubtful. 



Precipitable water in cm 



.06 .10 .25 .50 1.0 2.0 6.0 10.0 



99 98 97 95 93 90 83 78 



98 97 95 92 89 85 74 69 

 84 80 66 57 51 44 31 28 

 94 88 79 73 70 66 60 57 

 70 64 ----- — 



66 63 — — — — — — 



60 53 - — — - — - 



51 47 35 — — - — — 



8 4320000 



46 35 16 10 2 



96 94 65 - — — — — 



100 100 100 100 100 100 - — 



100 100 100 100 100 100 - — 



99 98 96 95 93 — — — 

 99 97 86 82 — — — — 

 94 90 80 60 — — — — 

 75 50 15 

 55 40 

 50 20 

 25 10 



0000000 



* These places require multiplication by the following factors to allow for losses in C0 2 gas. Under average 

 sea-level outdoor conditions the C0 2 (partial pressure = 0.003 atm) amounts to about 0.6 g/cm 8 . Paschen gives 

 3 times as much for indoor conditions. 



2/i to 3*1, for 2 g in ms path (95) ; for 140 g in m 2 path (93) ; 



4 " 5 " ' (93); " ' " " (70); more CO z no further effect; 



13 " 14, slight allowance to be made; 



14 " 15, 80 g in m 2 path reduces energy to zero; 



15 " 16, " " " " " " 



t These places require multiplication by 0.90 and 0.70 respectively for one air mass and 0.85 and 0.65 for two 

 air masses to allow for ozone absorption when the radiation comes from a celestial body. 



TABLE 568.— INFRARED TRANSMISSION OF VARIOUS 

 SUBSTANCES (percent) 187 



Fused quartz 2 mm 



1.0 " 



Crystal " 1.0 " 



Sulfur, rhombic . . .9 " 



Paraffin 2.0 " 



Mica 6(i 



Cellophane 40/* 



Celluloid \fi 



Black paper 1 mm 



Camphor soot .... * 



Pfund Bi black... * 

 Lampblack, 



water glass .8 



(1) (3) 7 12 21 20 26 30 25 30 30 



187 Barnes, Phys. Rev., vol. 39, p. 562, 1932. 

 * On celluloid 1/* thick. 



SMITHSONIAN PHYSICAL TABLES 



