37
Appendix A
Emissivity of common materials
(For reference only)
Name of material
Surface condition
Temperature
Emissivity (ε)
Aluminium
Non-oxidizing
100
0.20
Oxidation
100
0.55
Brass
Polished brown
20
0.40
Matte
38
0.22
Oxidation
100
0.61
Copper
Severe oxidation
20
0.78
Iron
Oxidation
100
0.74
Rust
25
0.65
Cast iron
Oxidized
200
0.64
Not oxidized
100
0.21
Wrought iron
Furry
25
0.94
Polished
38
0.28
Nickel
Oxidized
200
0.37
Stainless steel
Oxidation
60
0.85
Steel
Oxidation at 800
℃
200
0.79
General brick
Surface
20
0.93
Concrete
Surface
20
0.92
Glass
Polished plate
20
0.94
Lacquer
White
100
0.92
Natural color black
100
0.97
Carbon
Smoke black
25
0.95
Candle smoke
20
0.95
Rough surface of
graphite
20
0.98
Paint
Average of 16 colors
100
0.94
Paper
White
20
0.93
Sandy soil
Surface
20
0.90
Wood
Shaving
20
0.90
Water
Distilled water
20
0.96
Skin
Human beings
32
0.98
Ceramics
Fine
21
0.90
Thick
21
0.93
