SpectralEmissivity & Emittance

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Measurement of the surface emissivity of turbid waters

Chinese Journal of Oceanology and Limnology, Volume 5, Number 4, 363-369, DOI: 10.1007/BF02843818

“Measurement of the surface emissivity of turbid waters”, Liu Wenyao, R. T. Field, R. G. Gantt and V. Klemas


For interpreting thermal IR imagery of the ocean surface, the emissivity of the sea surface is usually assumed to be constant, approximately 0.98. However, the emissivity varies with the roughness of the sea surface, and the concentration and type of suspended particulates.

The emissivity variations caused by the suspended sediments introduce significant errors in the satellite-derived temperature maps of turbid coastal waters.Read More

Thermal infrared remote sensing of crude oil slicks

In: Remote Sensing of Environment, Volume 45, Issue 2, August 1993, Pages 225-231.

by John W. Salisbury a, Dana M. D’Aria a and Floyd F. Sabins Jr.b
aDepartment of Earth and Planetary Sciences, Johns Hopkins University, Baltimore U.S.A.
bChevron Oil Field Research Company, La Habra, California U.S.A.

(Abstract Online)
With all the interest on the Gulf Oil spill and recent accounts of the use by British Petroleum and others of Infrared Thermal Imaging to search for surface oil slicks, it seemed very timely to be sure we had included some links and summaries of articles dealing with the thermal Infrared optical properties of crude oil on seawater.

Article AbstractRead More

ASTM E307 – 72(2008) Standard Test Method for Normal Spectral Emittance

At Elevated Temperatures
Developed by ASTM Subcommittee: E21.04, on Space Simulation Test Methods, and in the Annual Book of ASTM Standards, Volume 15.0 Space Simulation; Aerospace and Aircraft; Composite Materials

Quoting from the standard’s Scope:

1. Scope

1.1 This test method describes a highly accurate technique for measuring the normal spectral emittance of electrically conducting materials or materials with electrically conducting substrates, in the temperature range from 600 to 1400 K, and at wavelengths from 1 to 35 ?m.

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

Obtaining directly from ASTM International has two options:

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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

Spectral emissivity of skin and pericardium

Spectral emissivity of skin and pericardium by J Steketee 1973 Phys. Med. Biol. 18 686-694 doi: 10.1088/0031-9155/18/5/307 Help

J Steketee, Department of Biological and Medical Physics, Erasmus University, Rotterdam, The Netherlands


A monochromator was modified to measure the emissivity, ?(?), of living tissue in the infrared region between 1 and 14 ?m. The infrared radiation from the tissue was compared with blackbody radiation and in this way ?(?) has been determined for white skin, black skin, burnt skin and pericardium.

A compensating skin thermometer was constructed to measure the temperature of the surface of the tissue. The temperature difference before and after contact between a gold ring and the surface was made as small as possible (0.05 K). A reference radiator with the same spectral radiance (experimentally determined) mas used in compensating for the environment.

It appeared that ?(?) for skin is independent of the wavelength and equal to 0.98+-0.01. These results contradict those of Elam, Goodwin and Lloyd Williams, but are in good agreement with those of Hardy and Watmough and Oliver.

In addition there was no difference between ?(?) for normal skin and burnt skin. Epicardium values were found to lie between 0.83 (fresh heart) and 0.90 (after 7 h and after 9 d).

Print publication: Issue 5 (September 1973)
PDF (504 KB)