The Raytek North America website contains a table of spectral emissivity for metals with values at 1.0 micrometers (micron). 1.6 microns and the 8-14 micron waveband. Many values are blank or labelled “nr” for “Not Recommended”. Many others cover relatively wide spans of values, varying as much as a factor of 4. The metals covered include many metal and alloys types.
Posts in category Metals & Alloys
A Basic Guide to Thermography A PDF Download from the Land Instruments website – (Last modified 15/11/04 -433kb – 14 pages). It contains a table of effective spectral emissivities over the 8 to 14 micrometer waveband for several common industrial and building materials as part of its introduction to Infrared Thermography.
This link enables one to download the 54 page introductory section of the CINDAS book (9.5 MB pdf), Thermophysical Properties of Matter, Vol. 7 Edited by Y.S. Touloukian and D.P. DeWitt IFC/Plenum -1970. It contains some excellent details on the meaning of emissivity, its terminology, the measurement techniques of 1970 and an introduction to the data organization of the full volume.
“The emissivity of metals often changes with wavelength. This means it is very difficult to determine what emissivity should be entered in passive, traditional pyrometers (all those that do not determine the emissivity during measurement). An example or two will show the difficulty.”
The graphs shown are from the “Thermophysical Properties of Matter ” vol 7; Thermal Radiative Properties, Ed By Y.S. Touloukian and D.P Dewitt, IFI-Plenum, New York 1970.
The original graphs in that volume were accompanied by the data represented by each curve, the literature citation for each and a description of the measurement and sample details represented by each curve.