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.
A technical paper in the Journal Title;Report by Research Group on Modeling of Optical Surface Properties of Steel Plates,(The Iron and Steel Institute of Japan S).
By KUROKAWA TAKAHARU (Tokyo Univ., Graduate School of Engineering, JPN) FUJIMURA SADAO(Tokyo Univ., Graduate School of Engineering, JPN)
“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.