101 



TABLE 82.— TOTAL EMISSIVITY VALUES OF VARIOUS MATERIALS AT 

 LOW TEMPERATURES* 



320°C 



500°C 



.77 



.75 



.72 

 .71 



.78 



Material Condition At 100°C 



Alleghany alloy No. 66 Polished .11 



Alleghany metal No. 4 polish .13 



Aluminum Commercial sheet .09 



Aluminum Polish .095 



Aluminum Rough polish .18 



Aluminum paint .29 



Brass Polished .059 



Carbon Rough plate .77 



Carbon, graphitized Rough plate .76 



Chromium Polished .075 



Copper Polished .052 



Copper-nickel Polished .059 



Iron Dark gray surface .31 



Iron Roughly polished .27 



Lamp black Rough deposit .84 



Molybdenum Polished .071 



Nickel Polished .072 



Nickel-silver Polished .135 



Radiator paint, black .84 



Radiator paint, bronze .51 



Radiator paint, cream .77 



Radiator paint, white .79 



Silver Polished .052 



Stainless steel Polished .074 



Steel Polished .066 



Tin Polished .069 



Tin Commercial coat .084 



Tungsten Polished coat .066 



Zinc Commercial coat .21 



* For reference, see footnote 38, p. 100. 



TABLE 83.— PERCENTAGE EMISSIVITIES OF METALS AND OXIDES 



True temperature °C 500 600 700 800 900 1000 1100 1200 



60 FeO.40 Fe 2 3 Total 85 85 86 87 87 88 88 89 



= Fe heated 



in air X = .65^ — — — 98 97 95 93 92 



NiO Total — 54 62 68 72 75 81 86 



\= .65m — — 98 96 94 92 88 87 



Platinum : 

 True temp. °C... 100 200 300 400 500 750 1000 1200 1400 1600 1700 

 App.* temp. °C... — — — — — — — 486 630 780 930 1005 



Total emiss. Pt... 3 1 4.0 5.1 6.1 7.0 8.0 10.3 12.4 14.0 15.5 16.9 17.5 



Oxides : X = 65/* N '0 Co.-,0 4 Fe.,0 4 MnaO, TiOo ThOg Y,,0 3 BeO NbO* V.O s Cr,,0 3 UsOg 



Solid 89 77 63 .. 52 57 61 37 71 69 60 30 



Liquid 68 63 53 47 51 69 31 



* As observed with total radiation pyrometer sighted on the platinum. 



TABLE 84.— TOTAL RADIATION FROM BARE AND SOOT-COVERED NICKEL 89 



(watts/cm 2 ) 



°K 400 



Soot-covered Ni 096 



Polished Ni initial heat.. .0092 

 " after above . . .0066 



39 Barnes, Phys. Rev., vol. 34, p. 1026, 1929. 

 SMITHSONIAN PHYSICAL TABLES 



