Spectral Emissivity & Emittance

NORMAL SPECTRAL EMITTANCE, 800-1400 K, Authors: Harrison, W.N. ; Richmond, J.C. ; Skramstad, H.K.

From the Energy Citations Database, OSTI IdentifierOSTI ID: 4830164

Technical Report, WADC-TR-59-510(Pt.III), National Bureau of Standards, Washington, D.C.,1961 Sep 01

ABSTRACT:

The equipment for direct measurement of normal spectral emittance was extensively modified by incorporation of a new external optical system that increased the amount of radiant energy available for measurement by a factor of about 10, and other associated changes. The test procedure was modified by incorporation of a zero line” correction. The equipment was calibrated by means of sector-disk attenuators which passed known fractions of the radiant flux from a blackbody furnace. Working standards of normal spectral emittance were prepared, calibrated, and shipped. An equation relating the normal spectral emissivity of a metal to five other parameters of the metal, each of which makes a non-linear contribution to the emissivity, was solved for one set of data by long hand” methods. Some progress was made in setting up a program for solution of the equation by use of an electronic computer. Equipment for the automatic recording of spectral emittance data in a form suitable for direct entry into an electronic computer, and on-line computation from spectral emittance data of total emittance or solar absorptance, was designed. Specifications for the equipment were prepared and bids received preparatory to placing an order for its procurement. (auth)

The spectral emittance of nickel- and oxide-coated nickel cathodes
S L Martin et al 1950 Br. J. Appl. Phys. 1 318-324

“Abstract. The spectral emittance values at a wavelength ? = 0.66 ? have been measured for various types of oxide-coated cathode, and for nickel cores, using a cylindrical diffuse reflectometer…”

“Normal spectral emittance of vanadium and tantalum for different surface conditions at temperatures above 1000 K”

By: Dorab N. Baria¹ and Renato G. Bautista²
(1) Department of Chemical Engineering, University of North Dakota, 58201 Grand Forks, North Dakota
(2) Department of Chemical Engineering and Group Leader, Ames Laboratory-USAEC, Iowa State University, 50010 Ames, Iowa

Journal: Metallurgical and Materials Transactions B
Publisher: Springer Boston
ISSN 1073-5615 (Print) 1543-1916 (Online)
Issue Volume 5, Number 7 / July, 1974
DOI 10.1007/BF02646324
Pages 1543-1546
Subject Collection Chemistry and Materials Science
SpringerLink Date Friday, June 15, 2007

Spectral emissivity of tungsten
Robert D. Larrabee
JOSA, Vol. 49, Issue 6, pp. 619-

Citation
R. D. Larrabee, “Spectral emissivity of tungsten,” J. Opt. Soc. Am. 49, 619- (1959)

Spectral emissivity of rhenium
D. T. F. Marple
JOSA, Vol. 46, Issue 7, pp. 490-(1956)

Citation
D. T. F. Marple, “Spectral emissivity of rhenium,” J. Opt. Soc. Am. 46, 490- (1956)

Variation with wavelength of the spectral emissivity of iron and molybdenum
Jack Eldon Taylor

JOSA, Vol. 42, Issue 1, pp. 33-(1952)

Citation
J. E. Taylor, “Variation with wavelength of the spectral emissivity of iron and molybdenum,” J. Opt. Soc. Am. 42, 33- (1952)

Spectral emissivity and the relation of true temperatures and brightness temperatures of platinum
Robert E. Stephens
JOSA, Vol. 29, Issue 4, pp. 158-161 (1939)

Citation
R. E. Stephens, “Spectral emissivity and the relation of true temperatures and brightness temperatures of platinum,” J. Opt. Soc. Am. 29, 158-161 (1939)

San Diego CA, USA –Surface Optics’ ET10 measures emissivity values in two most commonly used spectral regions, 3 to 5 and 8 to 12 microns.

Its main application is to produce emissivity values for the infrared cameras.

Advanced IR cameras require the input of an emissivity value for accurate temperature calculations. The emissivity values obtained from tables can be far from real leading to large temperature uncertainties.

The ET10 can be used in the lab or in the field and on small or large objects. With the ET10 one can measure emissivity of any surface in just a few seconds.

(more…)

Authors: Madding, Robert P.\
Affiliation: AA(Inframetrics, Inc.)
Publication:
Proc. SPIE Vol. 3700, p. 393-401, Thermosense XXI, Dennis H. LeMieux; John R. Snell; Eds. (SPIE Homepage)
Publication Date:03/1999
Origin:SPIEAbstract Copyright:
(c) 1999 SPIE–The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Bibliographic Code: 1999SPIE.3700..393M
Abstract: Extraction of temperatures or temperature differences with thermography is not possible without knowledge of the target emissivity…

A project under the Tufts University Research for Undergraduates 2000 Program described both theory and experiments related to welding of metals. Its report is online (CLICK HERE FOR FULL REPORT) and the Abstract is below.

Abstract

“The basic assumption behind the operating principle of modern thermal imaging thermometers is a “graybody approximation”. For a graybody, the emittance, reflectance and transmittance are constant for all wavelengths within the wavelengths within the waveband over which the instrument measures.

“In reality however, these factors change, and for applications that take place over a wide temperature range, the emissivity variation needs to be taken into account. This work suggests a method for an in-process emissivity identification and adaptation in order to dynamically calibrate infrared temperature measurement systems for applications like heat treatment, welding, cutting etc. A series of experiments has proven that once the spatial and temporal components of emissivity are decoupled, a model can be developed, which in conjunction with direct IR radiosity monitoring can provide information about the required emissivity compensation.”