Modifying a Surface To a Known Emissivity for Temperature Measurement

One of the techniques to deal with emissivity problems taught to most beginning Infrared Thermographers and many using so-called spot radiation thermometers or IR Thermometers, is to modify the surface with unknown spectral emissivity to one with a known emissivity. While much of that information seems to get lost in "How-To" books and notes, the Infraspection Institute publishes Tips of the Week on their IR/INFO website, open and free to the public.

They have graciously given us permission to reprint some of their tips, especially those that deal with handling some of problems and solutions for dealing with emissivity. Here, verbatim, is their Tip of September 29, 2003 "Modifying a Surface for Temperature Measurement", with permission.

"Unknown emittance values are often the greatest error source when taking infrared temperature measurements. This error source can be eliminated by modifying a target with a material having a known E value.

"Some of the modifying materials that thermographers commonly use include flat-finish spray paint, PVC electrical tape, masking tape, and spray deodorants containing powder.

"Prior to modifying any surface:

• Make sure that it is safe to contact the subject equipment.


• Obtain permission to modify the surface from the end user.


• Ascertain that the selected modifying material will not melt, catch fire or emit toxic fumes when heated.

"Once you have determined it is safe to modify a surface, proceed as follows:

1. Place radiometer at desired location and distance from target. Aim and focus.

2. Measure and compensate for Reflected Temperature.

3. Apply a surface modifying material having a known E value on target making certain that material is in full contact with target and there are no air pockets. Modifying material should be larger than radiometer’s spot measurement size for the chosen distance from the target.

4. Enter E value of modifying material into radiometer’s E setting.

5. Measure temperature of modifying material once it has reached thermal equilibrium with target.

6. For greater accuracy, repeat measurement three times and average the results.

"For more information on the above technique, refer to the Infraspection Institute Guideline for Measuring and Compensating for Reflected Temperature, Emittance and Transmittance available from Infraspection Institute."

Measurements of the infrared emissivity of a wind-roughened sea surface

Measurements of the infrared emissivity of a wind-roughened sea surface, By Jennifer A. Hanafin and Peter J. Minnett, published in Applied Optics, Vol. 44, Issue 3, pp. 398-411, in 2005 is more properly cited as:

J. A. Hanafin and P. J. Minnett, "Measurements of the infrared emissivity of a wind-roughened sea surface," Appl. Opt. 44, 398-411 (2005)

And the abstract is available online also as: www.opticsinfobase.org/abstract.cfm?URI=ao-44-3-398

It shows that measurements in the 8-12µm waveband region of the sea surface at viewing angles of 55°, in typical at-sea conditions, could introduce introduce errors of up to 0.7 K in sea-surface temperature measurements.

To Quote:

"The emissivity was found to increase in magnitude with increasing wind speed, rather than decrease, as predicted by widely used parameterizations. Use of these parameterizations can cause significant bias in remote sensing of sea-surface temperature in noncalm conditions."

Measuring the spectral emissivity of rocks and the minerals that form them

Measuring the spectral emissivity of rocks and the minerals that form them, By Miroslav Danov, Dimitar Stoyanov, and Vitchko Tsanev.

It is an online paper at the SPIE news room website. The tagline for the paper reads:

"A new ground-based technique measures minerals in their natural conditions, a prerequisite for satellite data processing".

The paper discusses a new measurement technique that uses both a scanning FTIR spectrometer and a gold-plated hemispherical mirror and provides data from tests using limestone as the test subject material.

Several references are cited, as follows:

Jingmin Dai, Xinbei Wang, Guibin Yuan, Fourier transform spectrometer for spectral emissivity measurement in the temperature range between 60 and 1500°C, J. Phy. 13, pp. 63-66, 2005.

S. Fonti, Spectral emissivity as a tool for the interpretation of Martian data: A laboratory approach, 32nd Annual Lunar and Planetary Science Conference, no. 1279, pp. 12-16, 2001.

A. M. Baldridge, P. R. Christensen, A laboratory technique for thermal infrared measurement of hydrated samples, 38th Lunar and Planetary Science Conference, pp. 2407, 2007. Lunar and Planetary Science XXXVIII, held March 12-16, 2007 in League City, Texas. LPI Contribution No. 1338

Z. Wan, D. Ng, J. Dozier, Spectral emissivity measurements of land-surface materials and related radiative transfer simulations, Adv. Space Reg. 14, no. 3, pp. 91-94, 1994.

T. W. Stuhlinger, E. L. Dereniak, F. O. Bartell, Bidirectional reflectance distribution function of gold-plated sandpaper, Appl. Optics 20, no. 15/1, 1981.

ASU Thermal Emission Spectra of Silicate, Carbonate, Sulfate, Phosphate, Halide, and Oxide Minerals

The spectral library is hosted by the Mars Space Flight Facility at Arizona State University (ASU) consists of thermal infrared emission spectra (typically 2000 - 220 cm-1) of a variety of geologic materials.

It is open and free, but one needs to register with a valid email address and take the time to learn how to access the data and obtain plots. It is not a trivial task.

Each spectrum comes with descriptive information, sample quality, and a comments field that describes any appropriate, related information.

To quote from the introduction to the library about the sources of data:

"Emission spectra were acquired using a Nicolet Nexus 670 interferometric spectrometer equipped with a CsI beamsplitter and an uncooled deuterated triglycine sulfate (DTGS) detector; the spectral range of the instrument is from 2000 — 220 cm-1 (5 — ~45 microns). Both the spectrometer and the sample chamber/glovebox were continuously purged with nitrogen gas during sample analysis to minimize atmospheric H2O and CO2 which also have absorption features in the 2000-220 cm-1 region of the spectrum. The particulate samples were heated in an oven to 80°C to improve the signal to noise ratio during spectral analysis (this temperature is maintained during analysis by placement of the sample cup on a heater element). The samples were raised into a water-cooled sample chamber that closely approximates a blackbody cavity [Ruff et al., 1997]. A total of 270 scans at 2-cm-1 sampling were taken over ~7 minutes and averaged together by the spectrometer. In the case of a hand sample, active heating during measurement is not possible. Hand samples were taken directly from the oven and placed into the sample chamber and 180 scans were taken over a period of ~5 minutes to minimize the effects of sample cooling. The spectral calibration method is a variation of method 1 of Christensen and Harrison [1993] as described in detail by Ruff et al., [1997]."

---

References cited above:

"Christensen, P.R., and S.T. Harrison, Thermal infrared emission spectroscopy of natural surfaces: Application to desert varnish coatings on rocks, J. Geophys. Res., 98 (B11), 19,819-19,834, 1993."Christensen, P.R., J.L. Bandfield, V.E. Hamilton, D.A. Howard, M.D. Lane, J.L. Piatek, S.W. Ruff, and W.L. Stefanov, A thermal emission spectral library of rock-forming minerals, J. Geophys. Res., 105,9735-9739, 2000. {ED NOTE: PDF DOWNLOAD}


"Feely, K.C. and P.R. Christensen, Quantitative compositional analysis using thermal emission spectroscopy: Application to igneous and metamorphic rocks, J. Geophys. Res., 104, 24195-24210, 1999.

"Lane, M.D. and P.R. Christensen, Thermal infrared emission spectroscopy of salt minerals predicted for Mars, Icarus, 135, 528-536, 1998.""Lane, M.D., Midinfrared emission spectroscopy of sulfate and sulfate-bearing minerals, American Mineralogist, in press, 2006.

"Ruff, S.W., P.R. Christensen, P.W. Barbera, and D.L. Anderson, Quantitative thermal emission spectroscopy of minerals: A laboratory technique for measurement and calibration, J. Geophys. Res., 102, 14,899-14,913, 1997."

Further reference publications related to the work at ASU may be viewed on the ASU website.

TES and Spectral Emissivity Curves: Quartz, Feldspar & Hornblende

This linked website discusses the background and flight of the instrument and also provides some interesting spectral emissivity curves for Quartz (SiO₂), Feldspar* and Hornblende** and an equal mixture of the two,

The TES instrument first flew aboard the Mars Observer spacecraft that was lost. The TES instrument was rebuilt and launched along with instruments aboard the new Mars Global Surveyor spacecraft.

The purpose of the TES device is to measure the spectral distribution of thermal infrared radiation emitted from Martian surfaces. The TES technique, can tell us much about the geology and atmosphere of Mars.

One can learn much about this method and the device by visiting the Arizona State University website pages that provide much more detail and background and reading through the TES News Archives.

[NOTE: The above curves actually exist on the Arizona State University website on their webpage address: http://tes.asu.edu/MARS_SURVEYOR/MGSTES/mixed_spec.gif]

The Thermal Emission Spectrometer is a scientific instrument and also Thermal Emission Spectroscopy is a measurement technique.

---

* K-feldspar end member KAlSi₃O₈, Albite end member NaAlSi₃O₈ or Anorthite end member CaAl₂Si₂O according to the Wikipedia article on Feldspar.
** The general formula (for Hornblende) can be given as (Ca,Na)_2-3(Mg,Fe,Al)₅(Al,Si)₈O₂₂(OH,F)₂ , according to the Wikipedia article on Hornblende..

Radiometric Temperature: Concepts and Solutions

A downloadable (PDF Format) "Application Note" from the Santa Barbara Infrared website. It explains the relationship between emitted thermal radiation, reflected thermal radiation, emissivity and the wavelength region used by a measuring device. It provides several informative examples with figures and graphs.

It reads in part:

".. a 40°C blackbody in a 40°C room would require no correction. But a 40°C blackbody in a 25°C room would have a radiometric temperature of less than 40°C....
Note that this error will be wavelength dependent. ...the reflected energy will be a different fraction of the total flux in the 3-5? band than in the 8-12? band."

AFR's SPECTRAL EMISSOMETER MEASUREMENT SERVICE

Advanced Fuel Research, Inc. (AFR) offers a testing service using the SERIES 205 SPECTRAL EMISSOMETER at their Connecticut-based laboratories.The Series 205 Spectral Emissometer is an automated bench-top device that measures spectral emissivity over a broad spectral range while simultaneously determining the surface temperature at the measurement location.The bench top, FT-IR based instruments are designed specifically to facilitate simultaneous measurements of surface spectral emittance and temperature, radiance, directional-hemispherical reflection and transmission using optical techniques over the spectral range at temperatures ranging from 50° to 2000°C.

The systems provide measurements of over a wide spectral range from 12,500 to 500 cm-1 (0.8 to 20 microns) for the Model 205 WB, and from 6,000 to 500 cm-1 (1.7 to 20 microns) for the Model 205 NB.

If you have a need for Emissometer measurements, please contact them.

For More Information Contact:
James R. Markham, CEO
Advanced Fuel Research, Inc.
87 Church Street, East
Hartford, CT 06108 USA

Tel: +1 860-528-9806 ext.104
Fax: +1 860-528-0648

Modeling and Simulation of Emissivity of Silicon-Related Materials and Structures

by N.M. RAVINDRA,(1,5) KRSHNA RAVINDRA,(1,2) SUNDARESH MAHENDRA,(1,3) BHUSHAN SOPORI,(4) and ANTHONY T. FIORY(1)
1.—Department of Physics, New Jersey Institute of Technology, Newark, NJ 07102. 2.—Intern atNJIT from Union County Magnet High School, Scotch Plains, NJ 07076. 3.—Intern at NJIT fromMillburn High School, Millburn, NJ 07041. 4.—National Renewable Energy Laboratory, Golden, CO 80401. Journal of ELECTRONIC MATERIALS, Vol. 32, No. 10, 2003, (Downloadable PDF Format)

Abstract:

"A brief review of the models that have been proposed in the literature to simulate the emissivity of silicon-related materials and structures is presented. The models discussed in this paper include ray tracing, numerical, phenomenological, and semi-quantitative approaches. A semi-empirical model, known as Multi-Rad, based on the matrix method of multilayers is used to evaluate the reflectance, transmittance, and emittance for Si, SiO2/Si, Si3N4/SiO2/Si/SiO2/Si3N4(Hotliner), and separation by implantation of oxygen (SIMOX) wafers. The influence of doping concentration and dopant type as well as the effect of the angle of incidence on the radiative properties of silicon is examined. The results of these simulations lead to the following conclusions: (1) at least within the limitations of the Multi-Rad model, near the absorption edge, the radiative properties of Si are not affected significantly by the angle of incidence unless the angle is very steep; (2) at low temperatures, the emissivity of silicon shows complex structure as a function of wavelength; (3) for SiO2/Si, changes in emissivity are dominated by substrate effects; (4) Hotliner has peak transmittance at 1.25 ?m, and its emissivity is almost temperature independent; and (5) SIMOX exhibits significant changes in emissivity in the wavelength range of 1–20 um."

"SPECTRAL EMISSIVITY OF HIGHLY DOPED SILICON"

by Curt H. Liebert and Ralph D. Thomas, NASA Lewis Research Center (Downloadable PDF File), APRIL 1968.

SUMMARY
"Measurements were made at temperatures of 300°, 882', and 1074' K of the normal was doped with a r s e n i c spectral emissivity of opaque, highly doped silicon. The silicon and boron to electron carrier concentrations of 2. 2X101', 3. %lo1', and 8 . 5 ~ 1 0 ~ ' electrons per cubic centimeter and hole carrier concentrationsof 6. 2X101' and 1 . 4 ~ 1 0 holes per cubic centimeter. The 30 K emissivity data were obtained at wavelengths from 2.5 to 35 microns. The high temperature emissivities were measured from 3.5 to 1 4 . 8 microns. Carrier concentrations and direct-current resistivity of the silicon were also measured. The carrier concentrations were determined from Hall measurements made at 30 K. The direct-current resistivity was measured at temperatures from 30 to 1200' K. These quantities (among others) were used in analytical calculations of the emissivities. Agreement of the Hagan-Rubens theory with experiment was found at wavelengths greater than 12 microns and at 30 K. Good agreement of the free carrier absorption theory with experiment w a s achieved at all wavelengths and temperatures investigated. The free carrier absorption theory predicts the emissivity in terms of the index of of these quantities are presented. A refraction and the absorption index. The values comparison of the values of the absorption index obtained herein with those obtained from the literature showed good qualitative agreement."

Normal Spectral Emittance of Some Metals, Carbon and SiC

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, Iridium, Iron, Molybdenum, Silicon Carbide, Stainless Steel and Titanium.

"Emissivity of silicon at elevated temperatures"

By P. J. Timans , Microelectronics Research Centre, Cavendish Laboratory, Cambridge University, Madingley Road, Cambridge CB3 0HE, United Kingdom Journal of Applied Physics -- November 15, 1993 -- Volume 74, Issue 10, pp. 6353-6364

The ASTER Spectral Library

The ASTER spectral library, is a compilation of almost 2000 spectra of natural and man made materials that is searchable by material. The search returns a list of materials that match your search criteria, you can see a scaled plot of the spectrum and the ancillary information information for the spectrum, you can also download the spectral data.

Data and (No. of samples) are: Minerals (1348), Rocks (244), Soils (58), Vegetation (4), Water, Snow & Ice (9), Man made materials (56), Lunar (17) and Meteorites (60)

Surface Spectral Emissivity Derived from MODIS Data

A downloadable PDF Format copy of a technical paper by Yan Chen, Sunny Sun-Mack, SAIC, Hampton, VA USA and Patrick Minnis, David F. Young, William L. Smith, Jr., Atmospheric Sciences, NASA Langley Research Center, Hampton, VA USA. A paper that was presented at SPIE's 3rd International Asia-Pacific Environmental Remote Sensing Symposium 2002: entitled Remote Sensing of the Atmosphere, Ocean, Environment, and Space, in Hangzhou, China, October 23-27, 2002.

ABSTRACT: "Surface emissivity is essential for many remote sensing applications including the retrieval of the surface skin temperature from satellite-based infrared measurements, determining thresholds for cloud detection and for estimating the emission of longwave radiation from the surface, an important component of the energy budget of the surface-atmosphere interface. In this paper, data from the Terra MODIS (MODerate-resolution Imaging Spectroradiometer) taken at 3.7, 8.5, 10.8, 12.0 ?m are used to simultaneously derive the skin temperature and the surface emissivities at the same wavelengths. The methodology uses separate measurements of the clear-sky temperatures that are determined by the CERES (Clouds and Earth's Radiant Energy System) scene classification in each channel during  the daytime and at night. The relationships between the various channels at night are used during the day when solar reflectance affects the 3.7-?m data. A set of simultaneous equations is then solved to derive the emissivities. Global results are derived from MODIS. Numerical weather analyses are used to provide soundings for correcting the observed radiances for atmospheric absorption. These results are verified and will be available for remote sensing applications."

Blackbody Radiation Visual Simulator

A VRML (3-D Virtual Reality Markup Language) demonstration of blackbody intensity distribution versus temperature and wavelength (This used to be on the University of Massachusetts website, but now is loacted on another site that its creator, Karen Strom has posted). It shows the shape of the Plank function for temperatures ranging from 1,000 K to 50,000 K for a range of wavelengths from the x-ray through the radio ranges.

Dark red lines color across the graphical display show the location of temperature isotherms. "Stickpins" on the red side of the distribution give the values of the temperature for 5 of these curves so that you can see the effect of varying the temperature.

This VRML + HTML package on Blackbody emission was constructed by Karen M. Strom who has retired from her scientific work life to pursue other interests. You can see what she is up to and contact her through her website:
www.karenstrom.com/

Thermal Radiative Properties: Coatings (PDF, 9.4 MB)

This link provides a downloadable pdf copy of Vol 9 of the introductory section of Thermal Properties of Matter compendium published by IFI/Plenum in 1970. The sestion deals with the theoretical background and methods of measurement of the optical properties presented. These include spectral emissivity.

Raytek's Spectral Emissivity Table for Non-metals

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".

Raytek's Emissivity Table for Metals

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.

A Basic Guide to (Infrared) Thermography

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.

Land Instruments Infrared Theory Notes

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.

Ircon's Plastic Film Transmission Curves

The definitive primer for non-contact plastic film temperature measurement by Ircon, Inc., Niles, Il, USA in a downloadable PDF format (556 Kb).

This Note has been a unique resource for IR temperature measurements in the thin film plastic film processing industry for more than 20 years. It was recently removed from the Ircon web page on plastics application, but the link to the Fluke website download seems to work.

(If you didn't know, Fluke bought Ircon a few years ago.)
In any event the link, above may not function and you might have to revert to the original Ircon webpage at: ircon.com/web/sol_ind/plas.php.

(Seems that some web designers and managers forget that there are legacy links to resources on older web pages that have value. We wish they would exercise the common courtesy of placing a redirect and notice of a resource link change, but then we wish for lot of things that only thoughtful, rational people do, and we aren't always kind or rational at times ourselves.)

There was also a link to the same download recently on the Fluke Instruments website at: support.fluke.com/ircon-sales/Download/Asset/3310192_6127_ENG_C_W.PDF. It might or might not work and if it doesn't, try back at the original web page.

The applications note describes the critical factors to be evaluated when selecting the proper instrument. It includes transmission curves for most common plastic films from which spectral emissivity estimates can be made.

More detailed or higher resolution measurements are usually recommended for specific products, but this is still an excellent summary of the key properties of a range of popular materials.

We expect to be asking companies for permission to house such useful resource documents here, but do not hold out much hope. But then agai, nothing ventured, nothing gained. Even if only one organization agrees, it will be a bonus for everyone, we think.

The Institute for Computational Earth System Science (ICESS)

ICESS is located on the University of California, Santa Barbara campus.

It provides an environment in which Earth and computer science are strongly coupled. Their focus is on research and graduate education in Earth sciences, with emphasis on processes governing the environmental optics of the Earth.

IR Emissivity Data on Vegetation at the MODIS Emissivity Library

Data available includes 24 sample of vegetation ranging from the Leaf of the Algerian Ivy (Hedera canariensis algerian ivy) to the Leaf of Sweet Gum tree (liquidamber styreciflua), one sample of bark of the Eucalyptus tree and three sample of dry grass.

Commentary of the site data reads:

"Vegetation Green vegetation typically has a very high emissivity because it is structured and contains water. Senescent (dry) vegetation has a more variable emissivity, especially in the 3 to 5 µm region, which depends on the type and structure of the cover type, the dryness, and so forth."

IR Emissivities of Soils and Sands at the MODIS UCSB Emissivity Library

Data is provided on: 9 samples of Nebraska Soil Lab, 14 samples of Oklahoma Soil, 10 samples of Death Valley, CA Soil, 10 samples of Railroad Valley, Nevada playa Soil, 2 samples of Railroad Valley, NV soil powder, 6 samples of Koehn, CA, 3 samples of Concord MA Soil, 9 samples of Page Arizona Sandy Soil, 2 samples of Goleta , CA Beach Sand, 3 samples of Soil - Prepared by ICESS, and more.

Commentary of the data reads:

"Soil and Sands exhibit stronger spectral features than many others. The "restralen" bands of quartz sand cause strong spectral features between 8 and 10 microns that depend on the grain size. The signature in the 3 to 5 µm region depends strongly on the water and organic content. The dryer, purer soils have lower emissivities in this region."

Water, Seawater, Ice, and Snow Sample Infrared Emissivities

From the MODIS (Moderate Resolution Imaging Spectrometer) UCSB Emissivity Library. Includes four sample for Water, three for Seawater, three for Ice and two for snow.

Commentary on the data on the site read, in part:

"Water, ice, and snow generally  have a high emissivity, 0.94 to 0.99, across the thermal infrared region. Snow is unusual in that it has a high reflectance in the solar (visible) region where most of the downwelling energy is during the day, and a very high emissivity in the thermal region."

MODIS (Moderate Resolution Imaging Spectrometer) UCSB Emissivity Library

"This library is a collection of Emissivity measurements of natural and man made materials that may be used as a source of spectral emissivities at the component level in the TIR BRDF models to calculate the scene emissivities in the split-window channels to be used in the LST algorithms..."

"This data set was collected by Dr. Zhengming Wan's Group at ICESS (Institute for Computational Earth System Science) located on the campus of UCSB (University of California, Santa Barbara)".

MODIS Data on Manmade Materials

The MODIS Database at the University of California at Santa Barbara includes spectral emissivity curves for Bricks, Tile, Masonry, Pavement, Stone, Lumber, Painted Sandpaper and miscellaneous materials.

Introductory Guide to Emissivity

An introductory guide on the National Physical Laboratory (NPL) website in the UK:

It says in part "For any particular wavelength and temperature, the amount of thermal radiation emitted by an object is directly proportional to the spectral emissivity of the object's surface. This is summarised in Planck's radiation equation:..."

Emissivity Measurement at IKE

For the measurement of the temperature ­dependant spectral emissivity as well as of the total emissivity from 300 °C to 2 500 °C two devices are available at IKE at the University of Stuttgart in Germany.    The IKE Group on Thermophysical Properties has been working on research projects in the field of thermophysical properties, like emissivity for pyrometry for more than twenty years.

Thermophysical Properties of Matter Database

"The Thermophysical Properties of Matter Database (TPMD), contains thermophysical properties of over 5,000 materials with approximately 50,000 data curves. This database is searchable by material, by property, or by partial string (name). For all data curves, the material composition, experimental conditions, raw or smoothed data, and references are given. Dynamic graphing capabilities allow users to compare the same property of multiple materials, change scale ranges, and export and import data. The database is continually updated and expanded."

"CINDAS LLC Pricing: Pricing for the database is determined based on company size and number of users. Special discounts are available for Academic organizations."

Contact CINDAS LLC to obtain pricing for your specific organization. They will be happy to develop a quote for you:

Email: info@cindasdata.com
Phone: 765-807-5400 or 765-807-6052
Phone (Toll free US and Canada): 1-800-696-7549
Fax: 765-807-5291

Thermal Radiative Properties Metallic Solids and Alloys (PDF, 9.5 MB)

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.

Emissivity & other infrared-optical properties

A series of FAQs online at the Evitherm website.

Change of infrared emissivity of metal surfaces during oxidation

High Temperatures - High Pressures, volume 30 (1998), issue number 3, pages 333-341.by Harald Mehling, Joachim Kuhn, Marco Valentin, Jochen Fricke Received 22-Jan-1997; Published in print 01-Jun-1998

Abstract

Derivation of spectral emissivity of metal surface

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).

Journal Code:N20011344

VOL.;NO.;PAGE.41-62(2001)

Figure&Table&Reference;FIG.9, REF.12

Pub. Country;Japan

Language;Japanes

By KUROKAWA TAKAHARU (Tokyo Univ., Graduate School of Engineering, JPN) FUJIMURA SADAO(Tokyo Univ., Graduate School of Engineering, JPN)

Spectral Emissivity of Tungsten & Molybdenum

The "Metals" page at the Far Associates website, Pyrometry.com states :

"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.

Hello World!

Welcome!

This site is for those who want or need to know more about spectral emissivity, what it is, how it is measured, reported and applies, or is applied to, Radiation Thermometry, including the two dimensional variation known popularly as Quantitative Thermal Imaging, and Spectral Radiometry.


The concept of this site is two-fold.

First, I am  organizing it and adding as much information as we can reasonably find.

Second, this is a community website. User inputs are encouraged and everything that goes on here is available to the public at large on the Web free of charge.

If you have or find an interesting resource that is not already here; share it in turn!

You can add a comment below at any time. We reject spam inputs the best we can, too.

If you want to be involved, contact me at: grp at MrPyro dot com.

We can use all the help we can get and you will get credit for everything you do.

One thing to note, the only advertising on this site will be text-only to help defray Temperature.com's cost of operating it and we expect it to be minimal, if any, since our costs are actually quite low.

Thanks for visiting and do come back!

Ray Peacock

Ivyland, PA U.S.A.