Manual
32
6 Emissivity of different materials
Material
Surface
Temperature (°C)
Emissivity (
έ)
Aluminium
Unoxidised
100
0.20
Oxidised
100
0.55
Brass
Brown polished
20
0.40
Unpolished
38
0.22
Oxidised
100
0.61
Copper
Oxidised
20
0.78
Iron
Oxidised
100
0.74
Rusty
25
0.65
Cast iron
Oxidised
200
0.64
Unoxidised
100
0.21
Welding rod
Rough
25
0.94
Polished
38
0.28
Nickel
Oxidised
200
0.37
Stainless steel
Oxidised
60
0.85
Steel
800 °C oxidised
200
0.79
Brick
-
20
0.93
Concrete
-
20
0.92
Glass
Smooth
20
0.94
Lacquer
White
100
0.92
Black
100
0.97
Coal
Smoky black
25
0.95
Candle smoke
20
0.95
