EMISSIVITY VALUES
Typical Emissivity Values-Metals
SURFACE
EMISSIVITY
Zinc (oxidized)
Galvanized iron
Tin-plated steel
Gold (polished)
Silver (polished)
Chromium (Polished)
Emissivity Values-Non-Metals
Refractory & Building Materials
Red brick (rough)
Fire clay
0.1*
0.3
0.1*
0.1*
0.1*
0.1*
0.75 to 0.9
0.75
Asbestos
Concrete
Marble
Carborundum
Plaster
Alumina (fine grain)
Alumina (coarse grain)
Silica (fine grain)
Silica (coarse grain)
o
Zirconium silicate up to 500 C
Zirconium silicate at 850
o
C
Quartz(rough)
Carbon (graphite)
Carbon (soot)
Timber (various)
0.95
0.7
0.9
0.85
0.9
0.25
0.45
0.4
0.55
0.85
0.6
0.9
0.75
0.95
0.8 to 0.9
Miscellaneous
Enamel (any color)
Oil paint (any color)
Lacquer
Matte black paint
Aluminum lacquer
Water
0.9
0.95
0.9
0.95 to 0.98
0.5
0.98
Rubber (smooth)
Rubber (rough)
Plastics(varous,solid)
0.9
0.98
0.8 to 0.95
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