Normal Spectral Emittance — selected materials
Because emittance is what is actually measured for a sample, this is the term used in the graphs below. As we have said, emissivity is the term in popular usage, and is understood to mean the value the operator needs to enter into the pyrometer. Unfortunately, as will become apparent in the graphs below, there is always a choice of values.
The following graphs are reproduced from the Thermophysical Properties of Matter, Vol. 7: Thermal Radiative Properties, Y.S. Touloukian and D.P. DeWitt, IFI/Plenum, New York, 1970.
aluminum
Aluminum emissivity as a function of wavelength.
copper
Copper emissivity as a function of wavelength.
graphite
Graphite emissivity as a function of temperature.
iridium
Iridium emissivity as a function of wavelength.
iron
Iron emissivity as a function of wavelength.
molybdenum
Molybdenum emissivity as a function of wavelength.
silicon carbide
Silicon carbide emissivity as a function of wavelength.
stainless steel
Stainless steel emissivity as a function of wavelength.
titanium
Titanium emissivity as a function of wavelength.
tungsten
Tungsten emissivity as a function of wavelength.
