SpectralEmissivity & Emittance

| Useful Data | Practices Measuring or Avoiding | Background & Theory|

Electro Optical Industries BB Emissivity Coatings

Electro Optical Industries (EOI) uses one of two high emissivity coatings on the surface of its blackbodies.

The EOI mid-temperature coating is used on both cavity and flat plate blackbodies that have a maximum operating temperatures of up to 210 °C.

Read the rest by visiting their webpage at: www.electro-optical.com/eoi_page.asp?h=What%20Is%20Emissivity?

Blackbody Emissivity Primer

From the Electro-Optical Industries website:

Typical Material Spectral Emissivity

“Effective emissivity is the ratio of the total amount of energy exiting a blackbody to that which is predicted by Planck’s law. This is the value most frequently referred to as “emissivity”.

Effective emissivity of a cavity type blackbody will normally be much higher than the surface emissivity due to the multiple energy bounces inside the body cavity.”

You can read the rest on this useful and informative webpage: www.electro-optical.com/html/bb_rad/emissivity/emisivty.asp

Measurements of Pool-Fire Temperature Using IR Technique. (419 K)

By Qian, C.; Saito, K.

Ref: Combustion Institute/Central and Western States (USA) and Combustion Institute/Mexican National Section and American Flame Research Committee. Combustion Fundamentals and Applications. Joint Technical Meeting. Proceedings. April 23-26, 1995, San Antonio, TX, Gore, J. P., Editor(s), 81-86 pp, 1995.

Sponsor: National Institute of Standards and Technology, Gaithersburg, MD

We made an attempt to measure the flame temperature of four different diameter hexane-pool-fires using IR technique. Emissivities for these four flames were estimated based on measurements of transmitted energy from a blackbody radiant source. The average flame temperature half way to the flame tip was 700-800 deg C, which was in good agreement with thermocouple-temperature measurements by others for a 3 m diameter hexane pool fire.

Click here to download a pdf version of the report:Measurements of Pool-Fire Temperature Using IR Technique. (419 K)

Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899 USA

Modeling of the thermal radiative behavior of rough coatings

Abstract 675 – Monte Carlo modeling of the thermal radiative behavior of rough coatings

Presented in the session Photothermal Techniques. Theory and Modeling at the 18th European Conference on Thermophysical Properties, Pau, France 31 Aug-4 Sep 2008
Mr Hector Gomarta*+
Dr Benoit Rousseaua
Dr Domingos De Sousa Menesesa
Dr Patrick Echeguta

a CNRS Orléans
Site Haute Température
1D avenue de la Recherche Scientifique
45071 cedex 02, France

*: Corresponding author
+: Presenting author


Surface roughness plays a crucial role in the thermal radiative properties of industrial systems, such as infrared heaters, plate near blackbody references used to calibrate a pyrometric setup. Nevertheless literature usually reports radiative properties simulations only for several wavelengths. In this study, we focus on modeling emissivity over a wide IR-spectral range for surfaces either measured by profilometry or numerically rebuild.

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