Handbook of OSML Libraries: Emittance

CRMHT - CNRS Centre de Recherche sur les Matériaux à Haute Température, Orléans, France
Mesure indirecte de l'émittance (Includes sample data for Silicon Dioxide)

Mesure de la réflectivité et de la transmissivité normales spectrales (10 à 40 000 cm-1 soit 1 000 à 0,25 µm).

L'émissivité normale spectrale se déduit indirectement par calcul de ces deux grandeurs par application des lois de Kirchhoff ,

i.e. at each wavelength, Emissivity =1 - Reflectivity - Transmissity

Emittance-WN

Handbook of OSML Libraries

	E - dielectric function N - complex refractive index RT - reflectivity, layer transmissivity WN - wave number
OSML Source : [Emitttance-WN]
Function Group : [Optical Functions]

Emittance-E

Emittance-E (AE) represents the fraction of the incident radiation that is absorbed (Kirchhoff law) by a sample with a plate shape. Its expression take into account for multiple reflections (no interference effects) and depends on the dielectric functions of the incident medium Ei, those of the material Eo and the thickness d of the sample. Function signature : Emittance-E(x,Ei,Eo,Thickness)Units The spectral dependence must be expressed in wave numbers (cm-1) and the thickness in (cm).

Emittance-N

Emittance-N (AN) represents the fraction of the incident radiation that is absorbed (Kirchhoff law) by a sample with a plate shape. Its expression take into account for multiple reflections (no interference effects) and depends on the complex refractive indexes of the incident medium Ni, those of the material No and the thickness d of the sample. Function signature : Emittance-N(x,Ni,No,Thickness)Units The spectral dependence must be expressed in wave numbers (cm-1) and the thickness in (cm).

Emittance-RT

Emittance-RT (ART) represents the fraction of the incident radiation that is absorbed (Kirchhoff law) by a sample with a plate shape. Its expression take into account for multiple reflections (no interference effects and depends on the reflectivity R and the layer transmissivity T of the sample. Function signature : Emittance-RT(R,T)

Planck-WN

Planck-WN (PWN) is the wave number version of the Planck function. Its expression depends on the temperature T. Function signature : Planck-WN(x,T) Constants : C1=1.1910 10-6 (W.m2) C2=1.4388 (cm.K)

See Also : [Optical Functions] [Reflectance-WN] [Transmittance-WN]
Handbook of OSML Libraries

Emissivity Calculator Online

The Pyrometer Instrument Company, manufacturers of the Pyrolaser® and Pyrofiber® products, among others, have a unique, online emissivity calculator that enables one to calculate the temperature measurement effect of: wavelength, emissivity setting and temperature for Infrared measurement wavelength bands ranging from 0.655 micrometer to 10.6 micrometers.

You can access the calculator by CLICKING HERE

(Pyrometer Instrument Company, 92 North Main Street • Bldg 18-D • Windsor, NJ 08561 • USA
Telephone: (609) 443-5522 • Fax: (609) 443-5590 • Email: sales [at] pyrometer.com)

EMISSIVITY EVALUATION OF FIXED POINT BLACKBODIES

A paper by Sergey Mekhontsev, Vladimir Khromchenko, Alexander Prokhorov, Leonard Hanssen
National Institute for Standards and Technology, Gaithersburg, MD, USA

Presented at the 9th International Symposium on Temperature and Thermal Measurements in Industry and Science (TEMPMEKO 2004), June 22-25, 2004, Dubrovnik, Croatia, Proceedings, Vol. 1, ed. by D. Zvizdic (2004), pp. 581-586.

ABSTRACT

A new facility for the characterization of infrared spectral emittance of materials has recently been developed at NIST. The facility operation is based on measurements of a sample’s spectral radiance and surface temperature with help of a set of variable temperature blackbodies and a spectral comparator. For highest accuracy, variable temperature blackbodies are calibrated in spectral radiance against a pair of fixed-point blackbodies with interchangeable crucibles of In, Sn, and Zn, and Al, Ag, and Cu, respectively. The spectral emissivity of the fixed-point blackbodies also needs to be accurately characterized. We employ a multi-prong approach: (1) Monte Carlo ray-trace modeling and calculations, (2) hemispherical reflectance measurements of the crucible cavity material flat sample, as well as the cavity itself, (3) direct spectral emittance measurements of the same samples using the facility, and (4) comparison of the fixed point blackbodies with each other as well as with variable temperature heat pipe blackbodies, using filter radiometers and the facility’s Fourier transform spectrometer. The Monte Carlo code is used to predict the cavity emissivity with input of the cavity shape and the emissivity and specularity of the cavity material. The reflectance measurements provide emissivity data of both the material and the cavity at room temperature. The results are used to compare with and validate the code results. The direct emittance measurements of the material provide the temperature dependence of the material emittance as code input. The code predicted results for the cavities at their operating temperature (freeze points) are then compared with the relative spectral radiance measurements. Use of this complete set of evaluation tools enables us to obtain the spectral emissivity of the blackbodies with reliably determined uncertainties.

It presently can be downloaded in PDF format from the NIST website by CLICKING HERE

IR spectral characterization of customer blackbody sources:

"First calibration results"

A paper by S. Mekhontsev, M. Noorma, A. Prokhorov, and L. Hanssen from NIST in the USA, Presented at Thermosense XXVIII, ed. by Jonathan J. Miles, G. Raymond Peacock, and Kathryn M. Knettel, Proc. of SPIE 6205, 620503 (2006).

ABSTRACT:

We summarize recent progress in our infrared (IR) spectral radiance metrology effort. In support of customer blackbody characterization, a realization of the spectral radiance scale has been undertaken in the temperature range of 232 °C to 962 °C and spectral range of 2.5 µm to 20 µm. We discuss the scale realization process that includes the use of Sn, Zn, Al and Ag fixed-point blackbodies (BB), as well as the transfer of the spectral radiance scale to transfer standard BBs based on water, Cs and Na heat pipes. Further we discuss the procedures for customer source calibration with several examples of the spectral radiance and emissivity measurements of secondary standard BB sources. For one of the BBs, a substantial deviation of emissivity values from the manufacturer specifications was found. Further plans include expansion of the adopted methodology for temperatures down to 15°C and building a dedicated facility for spectral characterization of IR radiation sources.

It presently can be downloaded from the NIST website in PDF format by CLICKING HERE

Emissivity Coefficients of Some Common Materials

We've been trying to preach to the inexperienced about Spectral Emissivity vs (just plain) emissivity.

The former is the subject used in Thermal Infrared Radiation Thermometry (Pyrometry, to some) and users of Thermal Infrared Imagers (Thermographic or Thermography Cameras) while the latter is the domain of radiation heat transfer considerations (except of course when spectral issues, like windows and atmospheres get in the way of the radiation transfer).

See the Emissivity Trail Pages at About Temperature Sensors if you'd like a brief rant or two.

But popular ignorance of details not withstanding, it is still a bit of a shock to see the term 'Emissivity" a prominent feature on both instrumentation and engineering websites, Here's another one with some sample text (no numbers here) from the Engineering Toolbox website. (Note: we corrected their misspelling of "emissivity" - as mentioned in our semi - rant pages on About Temperature Sensors, the word seems to be misspelled as often as it the term and the values are misunderstood and misused!)

The radiation heat transfer emissivity coefficient of some common materials as aluminum, brass, glass and many more

The emissivity coefficient - ? - indicates the radiation of heat from a 'grey body' according the Stefan-Boltzmann Law, compared with the radiation of heat from a ideal 'black body' with the emissivity coefficient ? = 1.

The emissivity coefficient - ? - for some common materials can be found in the table below. Note that the emissivity coefficients for some products varies with the temperature. As a guideline the emisivities below are based on temperature 300 K.
Surface Material

After Note: We have tried over the past ten years or so, with very limited success, to point out to organizations that should know better, including at least one each manufacturer of "Infrared Thermometers" and One Prominent Maker of Blackbody calibration furnaces, that they need to mend their errant ways and get with the one true religion of Spectral Emissivity.

Heck, the Church of the Flying Spaghetti Monster got a better response and Rodney Dangerfield gets more respect.

There are a few bright lights at the end of the emissivity "black hole", the new facilities at several national Metrology Laboratories, such as the one at NIST dealing with Infrared Optical Properties of Materials and the "Modern emissivity measuring facility for industry-orientated calibrations developed at PTB".

Hope springs eternal!

Determination of continental surface emissivity and temperature from satellite observations.

http://ara.lmd.polytechnique.fr/htdocs-public/products/emissivity/emissivity.html
Surface emission depends on surface parameters, i.e. emissivity and temperature. Emissivity of land surfaces substantially varies with vegetation, soil moisture, composition, and roughness (Nerry et al. (1988); Salisbury and D'Aria (1992)). As emissivity depends on wavelength, it is referred to as spectral emissivity. Emissivity also depends on the viewing angle.

Continental surface emissivity in the thermal infrared window is a key parameter for estimating the surface radiation budget. The energy emitted from the surface is proportional to the spectrally integrated surface emissivity and depends on the surface temperature. A 10% error (from 0.9 to 1.0, for example) on the emissivity approximately corresponds to a 10% error in the energy emitted from the surface (a portion of which may be compensated by the reflected incoming radiation). Prabhakara and Dalu (1976); Ogawa et al. (2003).

Wikipedia on Emissivity

Wikipedia has an entry for emissivity that is very brief and limited as of November 2008. Perhaps some visitors will improve it.

Will check periodically and let you know.

Link: http://en.wikipedia.org/wiki/Emissivity

Prediction of the thermal radiative properties of an X-Ray µ-tomographied porous silica glass

Prediction of the thermal radiative properties of an X-Ray µ-tomographied porous silica glass
B.Rousseau, D.De Sousa Meneses, P.Echegut, M.Di Michiel, J.-F.Thovert
Prediction of the thermal radiative properties of an X-Ray µ-tomographied porous silica glass
Applied Optics 46 4266-4276, (2007)

ABSTRACT
"A Monte Carlo ray tracing procedure is proposed to simulate thermal optical processes in heterogeneous materials. It operates within a detailed 3D image of the material, and it can therefore be used to investigate the relationship between the microstructure, the constituent optical properties, and the macroscopic radiative behavior. The program is applied to porous silica glass. A sample was first characterized by 3D x-ray tomography; then, its normal spectral emittance was calculated and compared with the experimental spectrum measured independently by high-temperature infrared emittance spectroscopy. We conclude with a discussion of the light-scattering mechanisms occurring in the sample."

Work performed at and reported by: Centre National de la Recherche Scientifique (CNRS), France.

Texture and porosity effects on the thermal radiative behavior of alumina ceramics

Texture and porosity effects on the thermal radiative behavior of alumina ceramics
Int. J. Thermophys. (in press) [view]

New Article
By: O.Rozenbaum, D.De Sousa Meneses; P.Echegut
Texture and porosity effects on the thermal radiative behavior of alumina ceramics
Int. J. Thermophys. (in press) [view]
ABSTRACT
"Thermal and optical properties of ceramics are dependent on radiation scattering and cannot be determined by the only knowledge of their chemical composition as for single crystals. In this paper, we investigate extrinsic effects such as roughness, porosity and texture on spectral emissivity of alumina ceramics. Roughness effects have an influence mainly in the opaque zone; an important porosity dependence and the presence of a critical porosity threshold were also pointed out in the semi-transparent zone. Furthermore, it was shown that two ceramics with similar total porosity but with different textures possess radically different emissivities, showing that grain size, pore size and spatial repartition of the grains is also crucial for the comprehension of the ceramics thermal properties"

Work performed at and reported by: Centre National de la Recherche Scientifique (CNRS), France.

Emissivity of Triangular Surfaces Determined by Differential Method

From Homogenization to Validity Limit of Geometrical Optics
Author: Taoufik Ghabara, Faouzi Ghmari and M. Salah Sifaoui
Abstract:

Geometric optics approximation for emissivity from triangular surfaces was compared with exact scattering predictions from electromagnetic theory. Rigorous electromagnetic scattering theory was numerically formulated based on the differential method. We have used a numerical simulation of the emissivity of gold and tungsten for a wavelength equal 0.55 micron to explore the validity of the geometric optics.

Surface parameter domains for the regions of accuracy of the geometric optics approximation are quantified and presented as functions of surface slope and roughness. Influence on the validity of the approximate method of multiple scattering, the shadowing effect and the cavity effect of metallic surface have been investigated.

For the latter, our interest was focused on the mechanism that enhances the emissivity of an interface when ruling a grating. It has been seen that the mechanism responsible for the enhancement of the emissivity depends very much on the period of the grating.

For gratings with a period much smaller than the wavelength, the roughness essentially behaves as a transition layer with a gradient of the optical index. For different period / wavelength ratio, we have found a good agreement between the differential method and the homogenization regime when the period was smaller.

Journal: American Journal of Applied Sciences
Issn: 15469239
EIssn: 15543641
Year: 2007
Volume: 4
Issue: 3
pages/rec.No: 146-154

DOAJ - Directory of Open Access Journals, 2008, Lund University Libraries, Head Office

ASTM E423 - 71(2008): Standard Test Method for Normal Spectral Emittance

Standard Test Method for Normal Spectral Emittance at Elevated Temperatures of Nonconducting Specimens ASTM E423 - 71(2008) - www.ASTM.org

1. Scope

1.1 This test method describes an accurate technique for measuring the normal spectral emittance of electrically nonconducting materials in the temperature range from 1000 to 1800 K, and at wavelengths from 1 to 35 ?m. It is particularly suitable for measuring the normal spectral emittance of materials such as ceramic oxides, which have relatively low thermal conductivity and are translucent to appreciable depths (several millimetres) below the surface, but which become essentially opaque at thicknesses of 10 mm or less.

1.2 This test method requires expensive equipment and rather elaborate precautions, but produces data that are accurate to within a few percent. It is particularly suitable for research laboratories, where the highest precision and accuracy are desired, and is not recommended for routine production or acceptance testing. Because of its high accuracy, this test method may be used as a reference method to be applied to production and acceptance testing in case of dispute.

1.3 This test method requires the use of a specific specimen size and configuration, and a specific heating and viewing technique. The design details of the critical specimen furnace are presented in Ref (1), and the use of a furnace of this design is necessary to comply with this test method. The transfer optics and spectrophotometer are discussed in general terms.

1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

2. Referenced Documents

E349 Terminology Relating to Space Simulation - www.ASTM.org

Full document current and on sale at the ASTM web store.

A Temperature and Emissivity Separation Algorithm...

A Temperature and Emissivity Separation Algorithm for Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Images

by: Alan Gillespie, Shuichi Rokugawa, Tsuneo Matsunaga, J. Steven Cothern, Simon Hook, and Anne Kahle
Click Here to view or save

Manuscript received October 31, 1997. This work was a collaborative effort of the U.S. and Japanese EOS/ASTER instrument teams, sponsored by the NASA EOS Project and ERSDAC.

A. Gillespie and J.S. Cothern are with the Department of Geological Sciences, University of Washington, Seattle, Washington 98195-1310, USA.

S. Rokugawa is with The University of Tokyo, Faculty of Engineering, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, JAPAN.

T. Matsunaga is with the Geological Survey of Japan, 1-1-3 Higashi, Tsukuba, Ibaraki 305, JAPAN.

S. Hook and A. Kahle are with the Jet Propulsion Laboratory 183-501, Pasadena, California 91109, USA

IEEE Log Number XXXXXXX

Abstract:
The ASTER scanner on NASA's EOS-AM1 satellite (launch: June, 1998) will collect five channels of TIR data with an NE DT of <0.3 K to estimate surface temperatures and emissivity spectra, especially over land, where emissivities are not known in advance. Temperature/emissivity separation (TES) is difficult because there are five measurements but six unknowns. Various approaches have been used to constrain the extra degree of freedom. ASTER's TES algorithm hybridizes three established algorithms, first estimating the normalized emissivities, and then calculating emissivity band ratios. An empirical relationship predicts the minimum emissivity from the spectral contrast of the ratioed values, permitting recovery of the emissivity spectrum. TES uses an iterative approach to remove reflected sky irradiance. Based on numerical simulation, TES should be able to recover temperatures within about 1.5K, and emissivities within about 0.015. Validation using airborne simulator images taken over playas and ponds in central Nevada demonstrates that, with proper atmospheric compensation, it is possible to meet the theoretical expectations. The main sources of uncertainty in the output temperature and emissivity images are the empirical relationship between emissivity values and spectral contrast, compensation for reflected sky irradiance, and ASTER's precision, calibration, and atmospheric correction.

STANDARDIZATION OF THERMAL EMITTANCE MEASUREMENTS. PART III.

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)

Exact spectral emissivity measurements for radiation thermometry (IR thermometry)

Modern emissivity measuring facility for industry-orientated calibrations developed at PTB

This news release is available in German.
CAPTION: Local variation of the directed spectral emissivity of a car paint sample at a wavelength of 4 µm, measured using a thermography camera. (IMAGE COURTESY PTB)
Industry and research are increasingly relying on non-contact temperature measurements with the aid of heat radiation, for example, for the reliable and reproducible drying of car paint.

In order to attain exact and reliable results, the emissivity of the measured surface has to be known. It can only be determined precisely in complex measuring facilities.

The Physikalisch-Technische Bundesanstalt (PTB) has developed a modern emissivity measuring facility for industry-oriented calibrations.

Infrared Spectral Emittance & Optical Properties of Yttrium Vanadate

Infrared Spectral Emittance and Optical Properties of Yttrium Vanadate
Phys. Rev. 169, 705 - 709 (1968)

by: H. E. Rast, H. H. Caspers, and S. A. Miller *
Infrared Division, Research Department, Naval Weapons Center Corona Laboratories Corona, California 91720

Received 13 November 1967
"ABSTRACT: The infrared spectral emittance E of single crystals of YVO₄ has been examined near 4.2 and 77°K in the wavelength range 4-125 micrometers..."
---------------------------
* Formerly Naval Ordnance Laboratory, Corona, Calif.

DIRECTIONAL SPECTRAL EMITTANCE OF A PACKED BED...

DIRECTIONAL SPECTRAL EMITTANCE OF A PACKED BED WITH COUPLED CONDUCTION-RADIATION HEAT TRANSFER

Dominique Baillis
Centre de Thermique de Lyon (CETHIL), UMR CNRS 5008, Institut National des Sciences Appliquées de Lyon, France

Jean-Francois Sacadura
Centre de Thermique de Lyon (CETHIL), UMR CNRS 5008, Institut National des Sciences Appliquées de Lyon, France

ABSTRACT

Recently a new experimental set up for measuring the directional spectral emittance has been developed. The both sides of packed bed sample are simultaneously heated with identical power laser beams (4kw, CO² 10.6 um) and the isothermal condition in the medium is assumed. In this paper, the coupled conduction-radiation equations are considered to investigate the effect of the temperature non-uniformity on the calculated value of the emittance and to verify if the isothermal assumption is valid. It is shown that the gradient temperature in the medium can be non negligible depending on the thickness and on the sample extinction coefficient.

download article

Spectral emittance of nickel and oxide-coated nickel cathodes

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...

"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

ASTM E423 - 71(2002)

ASTM E423 - 71(2002) Standard Test Method for Normal Spectral Emittance at Elevated Temperatures of Nonconducting Specimens

Developed by Subcommittee: E21.04 |Book of Standards Volume: 15.03

"1. Scope

1.1 This test method describes an accurate technique for measuring the normal spectral emittance of electrically nonconducting materials in the temperature range from 1000 to 1800 K, and at wavelengths from 1 to 35 m (microns?). It is particularly suitable for measuring the normal spectral emittance of materials such as ceramic oxides, which have relatively low thermal conductivity and are translucent to appreciable depths (several millimetres) below the surface, but which become essentially opaque at thicknesses of 10 mm or less..."

...

"2. Referenced Documents

E349 Terminology Relating to Space Simulation

Index Terms
emittance; infrared emittance; material radiative property; radiative heat transfer; spacecraft thermal control; spectral normal emittance; thermal radiation; ICS Number Code 49.025.01"

NFRC 301-2004: Standard Test Method for Emittance of Specular Surfaces...

NFRC 301-2004: Standard Test Method for Emittance of Specular Surfaces Using Spectrometric Measurements(Downloadable in PDF Format )
"1 Scope"

"This test method determines the normal and hemispherical emittance of a specular
surface. This test method describes the spectrometric measurement of the near-normal
specular reflectance in the mid-infrared range from mid-infrared 5 to 25 um. It includes
the calculation procedures required to determine the normal and hemispherical
emittance of said object.

This test method includes calibration instructions for the spectrometer and procedures
for selecting reflectance-reference standards."...

By:
National Fenestration Rating Council Inc.
6305 Ivy Lane, Suite 140
Greenbelt, MD 20770-1465
Voice: (301) 589-1776
Fax: (301) 589-3884
Email: info@nfrc.org
Website: www.nfrc.org

The Schumann-Runge Bands of O2

Spectral Emissivity of the Schumann-Runge Bands of Oxygen
Y. Ben-Aryeh
JOSA, Vol. 58, Issue 5, pp. 679- (1968)

Citation
Y. Ben-Aryeh, "Spectral Emissivity of the Schumann-Runge Bands of Oxygen," J. Opt. Soc. Am. 58, 679- (1968)

Measurements of the 4.3-mu CO2 Band 2560 - 3000 K

Spectral-Emissivity Measurements of the 4.3-mu CO₂ Band between 2560 degrees and 3000 degrees K
C. C. Ferriso, C. B. Ludwig, and L. Acton
JOSA, Vol. 56, Issue 2, pp. 171- (1966)

Citation
C. C. Ferriso, C. B. Ludwig, and L. Acton, "Spectral-Emissivity Measurements of the 4.3-mu CO2 Band between 2560 degrees and 3000 degrees K," J. Opt. Soc. Am. 56, 171- (1966)

Spectral emissivity of translucent solids

Low-temperature, directional, spectral emissivity of translucent solids
Dwight Weber
JOSA, Vol. 50, Issue 8, pp. 808- (1960)

Citation
D. Weber, "Low-temperature, directional, spectral emissivity of translucent solids," J. Opt. Soc. Am. 50, 808- (1960)
http://www.opticsinfobase.org/abstract.cfm?URI=josa-50-8-808

Spectral emissivity of solids at low temperatures

Spectral emissivity of solids in the infrared at low temperatures
Dwight Weber
JOSA, Vol. 49, Issue 8, pp. 815- (1959)

Citation
D. Weber, "Spectral emissivity of solids in the infrared at low temperatures," J. Opt. Soc. Am. 49, 815- (1959)

Spectral emissivity of tungsten

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 from 2 micrometers to 15 micrometers

Measurement of spectral emissivity from 2 micrometers to 15 micrometers
Charles D. Reid and E. D. McAlister
JOSA, Vol. 49, Issue 1, pp. 78- (1959)

Citation
C. D. Reid and E. D. McAlister, "Measurement of spectral emissivity from 2 micrometers to 15 micrometers," J. Opt. Soc. Am. 49, 78- (1959)
http://www.opticsinfobase.org/abstract.cfm?URI=josa-49-1-78

Spectral emissivity of rhenium

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)

Spectral emissivity of iron and molybdenum

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 & brightness temperatures of platinum

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)

ET10 Reflectometer Measures Emissivity

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.

Spectral emissivity of the anode of a carbon arc

The spectral emissivity of the anode of a carbon arc
K. Schurer
Applied Optics, Vol. 7, Issue 3, pp. 461-

Citation
K. Schurer, "The spectral emissivity of the anode of a carbon arc," Appl. Opt. 7, 461- (1968)

Spectral emittance - spectrally selective solar absorbing layers

Infrared spectral emittance profiles of spectrally selective solar absorbing layers at elevated temperatures

D. E. Soule and D. W. Smith

Applied Optics, Vol. 16, Issue 11, pp. 2818- (1977)

Infrared Emission Spectroscopy of Polymer Reactions

Noninvasive Polymer Reaction Monitoring by Infrared Emission Spectroscopy with Multivariate Statistical Modeling
Randy J. Pell, James B. Callis, and Bruce R. Kowalski
Applied Spectroscopy, Vol. 45, Issue 5, pp. 808-818 (1991)

Abstract

"Infrared absorption and emission spectroscopy have been used to monitor the curing of a commercial paint product. Principal component analysis of the absorption data indicates that three factors are needed to explain the observed spectral/temporal variance. The interpretation of this finding in terms of changes in the physical state of the reaction mixture is discussed. A similar analysis of the emission data proved more difficult due to a nonlinear concentration/response relationship. A linearization step based on an approximate theoretical model is suggested. The absorption, linearized emittance, and raw emittance data are fit to a two-step sequential rate model using multivariate nonlinear optimization and error estimates derived by Monte Carlo calculations. Better agreement of the model parameters between the absorbance and emittance data is found after linearization, but it is found that linearization introduces large errors in the nonlinear parameter estimates. Comparisons of model parameters for the raw emittance data at different temperatures are made."

Citation
R. J. Pell, J. B. Callis, and B. R. Kowalski, "Noninvasive Polymer Reaction Monitoring by Infrared Emission Spectroscopy with Multivariate Statistical Modeling," Appl. Spectrosc. 45, 808-818 (1991)

IR Emission Spectroscopy of Molten Salts and Other Liquids

IR Emission Spectroscopy of Molten Salts and Other Liquids Using Thick Samples as Reference
J. Hvistendahl, E. Rytter, and H. A. Øye
Applied Spectroscopy, Vol. 37, Issue 2, pp. 182-187 (1983)

Abstract

"The IR emittance of liquids relative to a blackbody is dependent on the reflectivity at the surface of the sample. This dependency leads to distortions in the bandshapes except when the absorption coefficient or the sample thickness is very low. The use of an opaque (i.e. very thick) sample as a reference eliminates the distortions in the bandshapes. A new emittance ?* = (emission of a thin sample)/(emission of an opaque sample) has been introduced. A theoretical analysis as well as experimental work on chloroaluminate melts demonstrate that the emittance ?* gives a better representation of the ideal sample property of interest, i.e., the internal transmittance of the sample, than the usual emittance with a blackbody as a reference."

Citation
J. Hvistendahl, E. Rytter, and H. A. Øye, "IR Emission Spectroscopy of Molten Salts and Other Liquids Using Thick Samples as Reference," Appl. Spectrosc. 37, 182-187 (1983)

Emittance of infrared windows

Emittance measurements on infrared windows exhibiting wavelength dependent diffuse transmittance
S. E. Hatch
Applied Optics, Vol. 1, Issue 5, pp. 595-601

Citation
S.E. Hatch, "Emittance measurements on infrared windows exhibiting wavelength dependent diffuse transmittance," Appl. Opt. 1, 595-601 (1962)

Spectral emittance of refractory materials

Spectral emittance of refractory materials
Henry H. Blau, Jr. and John R. Jasperse
Applied Optics, Vol. 3, Issue 2, pp. 281-(1964)

Citation
H. H. Blau, Jr.and J. R. Jasperse, "Spectral emittance of refractory materials," Appl. Opt. 3, 281- (1964)

Spectral emittance of optical materials

Infrared spectral emittance measurements of optical materials
D. L. Stierwalt
Applied Optics, Vol. 5, Issue 12, pp. 1911-(1966)

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Citation
D. L. Stierwalt, "Infrared spectral emittance measurements of optical materials," Appl. Opt. 5, 1911- (1966)

The RET Theory

Ircon, Inc., a leading producer of industrial radiation thermometers, line scanners and quantitative thermal imagers, in its training programs for many years used to teach something they called the RAT Theory.

Reflectance, Absorbtance and Transmittance, or the coefficients of them, abbreviated as R, A &T must sum to 100%, or R + A + T=1.

An easy way for newcomers to Infrared radiation thermometry to remember a very important concept.

The associated concept is that Absorbtance=Emittance, or A=E. Or the RAT theory could be written as R+E+T=1 and renamed the RET Theory.

So, while not as easily recalled, the RET Theory name just didn't catch on as easily as the RAT Theory.

(BTW, whenever I tried to teach some basics of Radiation Thermometry, I used to call it the TAR Theory because I thought it might "stick" better- it didn't - RAT wins by a landslide every time.)

All this is a lead in to the wonderful resources by the folks at  LabSphere for those who want to know or learn how to measure emittance or absorbtance through the roundabout way of measuring reflectance and transmittance first and then doing a bit of math.

They have a readily downloadable 26 page PDF document entitled "A Guide to Integrating Sphere Radiometry and Photometry".

It explains far more than the RAT or RET or TAR theories about optical radiation metrology.

I think it and many of their online aids are well worth a read.

Spectral emittance: powders

Spectral emittance and reflectance of powders
J. R. Aronson, A. G. Emslie, T. P. Rooney, I. Coleman, and G. Horlick
Applied Optics, Vol. 8, Issue 8, pp. 1639- (1969)

Citation
J. R. Aronson, A. G. Emslie, T. P. Rooney, I. Coleman, and G. Horlick, "Spectral emittance and reflectance of powders," Appl. Opt. 8, 1639- (1969)

Determining the emittance of solids

Cavity methods for determining the emittance of solids
E. M. Sparrow, P. D. Kruger, and R. P. Heinisch

Applied Optics, Vol. 12, Issue 10, pp. 2466- (1973)

Citation
E. M. Sparrow, P. D. Kruger, and R. P. Heinisch, "Cavity methods for determining the emittance of solids," Appl. Opt. 12, 2466- (1973)

Spectral emittance of particulate materials

Spectral reflectance and emittance of particulate materials
A. G. Emslie and J. R. Aronson
Applied Optics, Vol. 12, Issue 11, pp. 2563-

Citation
A. G. Emslie and J. R. Aronson, "Spectral reflectance and emittance of particulate materials," Appl. Opt. 12, 2563- (1973)

Spectral emissivity of hydrogen chloride

Spectral emissivity of hydrogen chloride from 1000-3400 cm-1 V
V. Robert Stull and Gilbert N. Plass
JOSA, Vol. 50, Issue 12, pp. 1279- (1960)

Citation
V. R. Stull and G. N. Plass, "Spectral emissivity of hydrogen chloride from 1000-3400 cm-1 V," J. Opt. Soc. Am. 50, 1279- (1960)

Emissivity measurement and temperature correction accuracy considerations

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...

Emissivity Adaptation

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."

Polarized spectral emittance from periodic micromachined surfaces. II. Doped silicon: Angular variation

PJ Hesketh, JN Zemel, B Gebhart - Physical Review B, 1988 - APS Polarized spectral emittance from periodic micromachined surfaces. II. VOLUME 37, NUMBER 18

From the Abstract:The polarized directional spectral (3 um <=lambda =>14um) emittances (PDSE’s) of highly doped, micromachined, periodic structures on silicon were measured...

Polarized spectral emittance from periodic micromachined surfaces. I. Doped silicon: The normal direction

Peter J. Hesketh, Jay N. Zemel & Benjamin Gebhart ; Physical Review B.37.10795
VOLUME 37, NUMBER 18 1988

From the Abstract: The normal, polarized spectral (3 um <=lambda =>14um) emittances of highly doped, micromachined, periodic structures on heavily phosphorus-doped (110) silicon ([P]?5×10¹⁹cm^-3) were measured for .....

High-Temperature Spectral Emittance of Oxides of Erbium, Samarium, Neodymium and Ytterbium

Author: Guazzoni, Guido E.¹

Source: Applied Spectroscopy, Volume 26, Issue 1, Pages 1-113 (January/February 1972) , pp. 60-65(6)

Publisher: Society for Applied Spectroscopy

Abstract: Normal spectral emittance data are reported for solid specimens of the oxides of erbium, samarium, neodymium, and ytterbium... over the spectral range ..0.5-5.0 um and at sample temperatures from 1540 up to 1870 K.

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