Spectral Emissivity & Emittance

On the 13-15 June, 2001, in Budapest, Hungary, the 12th International Conference on Thermal Measurements and Thermogrammery (THERMO) was held.

Among the papers were two by Prof. Dr.-Ing. W. Bauer, Dipl.-Phys., A. Moldenhauer, Dipl.-Phys. & M. Rink of the Gerhard Mercator Universität Duisburg, Germany

The first presentation was entitled:

“New System for Spectral Emissivity Measurements at the University of Duisburg”

(Click on the link to access the Abstract in PDF Format)

The second was:

“Spectral emissivities of metals dependent on heat-treating processes”.

(Click on the link to access the Abstract in PDF Format)

Other papers by the members of the Duisburg Universitat have their abstracts listed on this Conference information page, also.

Contacts for more information are:

Prof. Dr. Ing. W. Bauer, Gerhard-Mercator-Universität, Duisburg, Germany

Fachbereich 8, Fachgebiet Energieeinsatz(Germany)
47048 Duisburg
Tel.: +49 203/379-3629
Fax.: +49 203/379-3464

Prof. Dr. Ing. W. Bauer

Email: bauer [at] ihg.uni-duisburg.de

and

Thomas Funke Dipl.-Ing.

Email: Thomas.Funke [at] uni-duisburg.de

Homepage: www.ihg.uni-duisburg.de/energieeinsatz/

The “Emissivity” page on the FAR Associates website includes a discussion of their unique instrument along with graphs and some tables of spectral emissivity values are evidently all reproduced from the Thermophysical Properties of Matter, Vol. 7: Thermal Radiative Properties, Y.S. Touloukian and D.P. DeWitt, IFI/Plenum, New York, 1970. These include curves for: Carbon (Graphite), Tungsten, Aluminum, Copper, Iridum, Iron, Molybdenum, Silicaon Carbide, Stainless Steel and Titanium.

The Raytek North America website includes a table for the emissivity of a large range of non-metallic materials that includes common building materials, ceramics, glasses and natural materials including ice & water in as many as four wavelength regions.

Wavebands covered include 1.0 micrometer (micron), 5.0 microns, 7.9 microns and the 8-14 micron band. No specific data and the limits of the various wavebands and there are many instances where the wavelength region is labelled as “nr” meaning “Not Recommended”.

Infrared Theory Notes-(Last updated 04/11/04, PDF Download of 547kb - 43 pages) contains not only some simple explanations of the key features of Radiation Thermometry, how it works and how IR Thermometers work in various measurement situations, but also provides some unique graphical representations of the transmission of glasses (see pages 30-33).

It also discusses thin plastics. In the latter case, see pages 34-36 for unique emissivity data and curves versus material type and thickness at 3.43 micrometers (microns) and explanations of an alternate choice waveband region at 7.9 microns.