Infrared spectral emissivity characterization facility at NIST

Hanssen, Leonard M.; Mekhontsev, Sergey; Khromchenko, Vladimir B.

doi:10.1117/12.542224

Cited by 37 publications

(14 citation statements)

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“…In and Sn blackbodies have 7-mm diameter exit apertures and are designed to have high IR emissivity and plateaux of several hours duration to allow long measurement times. Further details of their design and additional evaluations are described in an earlier paper [8].…”

Section: Realization Componentsmentioning

confidence: 99%

“…A facility for direct measurements of spectral directional emissivity of materials [8], developed earlier in our group as part of the Fourier Transform Infrared Spectrophotometry Laboratory, has certain capabilities for spectral characterization of blackbody (BB) sources [9]. These capabilities, along with numerous excellent contributions from other groups [10][11][12][13], have allowed us to gain the necessary experience to proceed with establishment of a dedicated thermal IR spectroradiometric facility.…”

Section: Introductionmentioning

confidence: 99%

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NIST Radiance Temperature and Infrared Spectral Radiance Scales at Near-Ambient Temperatures

Mekhontsev

Khromchenko²,

Hanssen

2008

Int J Thermophys

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The realization and the dissemination of spectral radiance and radiance temperature scales in the temperature range of −50 to 250 • C and spectral range of 3-13 µm at the National Institute of Standards and Technology are described. The scale is source-based and is established using a suite of blackbody radiation sources, the emissivity and temperature of which have been thoroughly investigated. The blackbody emissivity was measured using the complementary approaches of modeling, reflectometry, and the intercomparison of the spectral radiance of sources with different cavity geometries and coatings. Temperature measurements are based on platinum resistance thermometers and on the direct use of the phase transitions of pure metals. Secondary sources are calibrated using reference blackbody sources, a spectral comparator, a controlled-background plate, and a motion control system. Included experimental data on the performance of transfer standard blackbodies indicate the need for development of a recommended practice for their specification and evaluation. Introduced services help to establish a nationwide uniformity in metrology of nearambient thermal emission sources, providing traceability in spatially and spectrally resolved radiance temperature, spectral radiance, and background-corrected effective emissivity. S. N. Mekhontsev (B) · L. M. Hanssen Optical Technology Division (844), National

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Section: Realization Componentsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

NIST Radiance Temperature and Infrared Spectral Radiance Scales at Near-Ambient Temperatures

Mekhontsev

Khromchenko²,

Hanssen

2008

Int J Thermophys

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“…Many measurement methods have been developed to measure the spectral emissivity of materials at various temperatures and spectral ranges. The direct measurement method of the spectral emissivity was widely used that compare the sample spectral intensity to the blackbody spectral intensity at the same temperature [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. For example, Rozenbaum et al [4] used a spectroscopic method to measure the directional spectral emissivity of semi-transparent materials for wavelengths of 10-12000 cm À1 and temperatures of 600-3000 K with the sample heated by a carbon dioxide laser.…”

Section: Introductionmentioning

confidence: 99%

“…For example, Rozenbaum et al [4] used a spectroscopic method to measure the directional spectral emissivity of semi-transparent materials for wavelengths of 10-12000 cm À1 and temperatures of 600-3000 K with the sample heated by a carbon dioxide laser. Hanssen et al [7] used a facility at NIST to measure spectral emissivities for wavelengths of 1-20 lm and temperatures of 600-1400 K. The sample surface temperature was measured using a non-contact method with a sphere reflectometer. Dai et al [9] used a spectral emissivity measurement system with a Fourier transform spectrometer with a spectral range between 0.6 and 25 lm.…”

Section: Introductionmentioning

confidence: 99%

Measurements of the directional spectral emissivity based on a radiation heating source with alternating spectral distributions

Fu¹,

Duan²,

Tang³

et al. 2015

International Journal of Heat and Mass Transfer

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“…The surface emissivity term, which is necessary to perform complete column infrared radiative transfer calculations, is exactly unity for an ideal blackbody, but emissivity of real surfaces can be spectrally dependent and is generally lower than unity. Emissivity characterization of real materials is highly nontrivial because of microscopic heterogeneity, surface reflections, and surface geometry (15). It exhibits angular and spectral dependence, and its characterization outside of the laboratory requires remote sensing, as terrestrial surfaces exhibit great spectral and temporal variation in this quantity (16,17).…”

Section: Significancementioning

confidence: 99%

Far-infrared surface emissivity and climate

Feldman

Collins

Pincus

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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Presently, there are no global measurement constraints on the surface emissivity at wavelengths longer than 15 μm, even though this surface property in this far-IR region has a direct impact on the outgoing longwave radiation (OLR) and infrared cooling rates where the column precipitable water vapor (PWV) is less than 1 mm. Such dry conditions are common for high-altitude and highlatitude locations, with the potential for modeled climate to be impacted by uncertain surface characteristics. This paper explores the sensitivity of instantaneous OLR and cooling rates to changes in far-IR surface emissivity and how this unconstrained property impacts climate model projections. At high latitudes and altitudes, a 0.05 change in emissivity due to mineralogy and snow grain size can cause a 1.8-2.0 W m −2 difference in the instantaneous clearsky OLR. A variety of radiative transfer techniques have been used to model the far-IR spectral emissivities of surface types defined by the International Geosphere-Biosphere Program. Incorporating these far-IR surface emissivities into the Representative Concentration Pathway (RCP) 8.5 scenario of the Community Earth System Model leads to discernible changes in the spatial patterns of surface temperature, OLR, and frozen surface extent. The model results differ at high latitudes by as much as 2°K, 10 W m −2 , and 15%, respectively, after only 25 y of integration. Additionally, the calculated difference in far-IR emissivity between ocean and sea ice of between 0.1 and 0.2, suggests the potential for a far-IR positive feedback for polar climate change.climate change | positive feedback | emissivity | remote sensing | polar amplification

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Infrared spectral emissivity characterization facility at NIST

Cited by 37 publications

References 0 publications

NIST Radiance Temperature and Infrared Spectral Radiance Scales at Near-Ambient Temperatures

NIST Radiance Temperature and Infrared Spectral Radiance Scales at Near-Ambient Temperatures

Measurements of the directional spectral emissivity based on a radiation heating source with alternating spectral distributions

Far-infrared surface emissivity and climate

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