Mechanical Tables - Total Emissivity of Surfaces at Quoted Temperatures

Total Emissivity of Surfaces at Quoted Temperatures



Material	Temperature (^oC)	Total Emissivity

Iron

(i) Cast and polished	200	0.21
(ii) Rusted plate	19	0.69
(iii) Molten C.I.	1300 - 1400	0.29

Steel

(i) Polished	100	0.066
(ii) Sheet, oxidized	24	0.82
(iii) Plate, rough	38 -372	0.94 - 0.97
(iv) Molten	1522 - 1650	0.43 - 0.40

Aluminium

(i) Commercial sheet	100	0.09
(ii) Heavily oxidized	93 - 505	0.20 - 0.31
Copper; polished	100	0.052
Chromium; polished	100	0.075

Brass

(i) Polished	100	0.06
(ii) Rolled plate	22	0.06
Galvanized iron	28	0.23
Silver; polished	227 - 627	0.02 - 0.032
Tungestun filament	3320	0.39
Platinum filament	27 - 1230	0.036 - 0.192
Nichrome wire	49 - 1000	0.65 - 0.79
Aluminium paints	100	0.27 - 0.67
Oil paints	100	0.92 - 0.96
Glass	22	0.94
Asbestos board	23	0.96
Plaster; rough lime	10 - 87	0.91

Brick

(i) Red; rough	21	0.93
(ii) Building	1000	0.45
(iii) Fire clay	1000	0.75
(iv) Magnesite (refractory)	1000	0.38
Flat black lacquer	38 - 94	0.96 - 0.98
Water	0 - 100	0.95 - 0.96
Candle soot	97 - 272	0.952
Lamp-black	50 - 1000	0.96