Gray Body definition of Gray Body in the Free Online Encyclopedia.

Gray Body

(or nonselective radiator), a body whose absorptivity is less than 1 and is independent of the wavelength A of the radiation. The absorptivity α_λ,T of all real bodies depends on A; in other words, such bodies absorb selectively. For this reason, they are regarded as gray bodies only in ranges of A where α_{λ, T} is approximately constant. Substances having the properties of a gray body in the visible region of the spectrum include coal, with α_λ,T = 0.80 at 125°-625°C; carbon filaments of incandescent lamps, with α_λ,T = 0.526 at 1040°-1405°C; and carbon black, with α_λ,T = 0.94–0.96 at 100°-200°C. Black platinum and bismuth absorb and radiate as gray bodies in the widest range of λ—from visible light to 25–30 micrometers (α_λ,T = 0.93–0.99).

The heat radiation of a gray body is identical to the radiation of a blackbody in spectral composition but has a lower radiance. The laws governing the radiation of a blackbody are applicable, with only the constants being replaced, to the radiation of a gray body. These laws include Planck’s law, Wien’s law, and the Rayleigh-Jeans law. The concept of a gray body is used in optical pyrometry.

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No references found	This dinosaur sported a generally gray body, a reddish-brown, Mohawk-like crest and facial speckles, and white feathers on its wings and legs, with bold black-spangled tips. Color palette of 150-mln yr old feathered dino shows vibrant hues by Asian News International It was a tightly hewn thing with a gunmetal gray body, black vinyl top and tan interior. 2010 Ford Mustang Premium V-6 Convertible: Dream machine vs. N.Y. ... by The Star (Amman, Jordan) The lid's light blue color contrasts with the white and gray body, and the instrument panel gracefully curves out from the body, making for a sturdy yet aerodynamic appearance. The 2006 IBO Laboratory Equipment Design Awards by Instrument Business Outlook	gravity tank gravity tide Gravity Variations gravity vector gravity wall gravity water system gravity water tank gravity wave gravity wheel conveyor gravity wind gravity yard gravity, centre Gravity, Force of gravity-collapse structure gravity-flow gathering system gravity-gradient attitude control gravity-type refuse chute Gravure gravure coating gravure printing Grawitz's tumor grawlix gray gray antimony gray blight Gray Body gray box gray box testing gray cast-iron pipe gray casting Gray clay treating gray cobalt Gray code gray copper ore Gray County Gray Eminence gray filter Gray Forest Soil gray fox gray goods gray hairs gray hematite Gray Heron gray iron gray leaf spot gray mail gray manganese ore gray matter gray mold gray scab gray scale	grawlix gray gray gray gray gray gray gray Gray (color) Gray (color) Gray (color) Gray (horse) Gray (unit) Gray (unit) gray alder Gray alien Gray Alpine cattle Gray antimony Gray antimony gray area gray area gray area gray area Gray Areas Gray Army Airfield Gray baby syndrome Gray Biotechnology gray birch gray birch gray blight Gray Body gray box gray box testing Gray brich Gray brich Gray buck Gray Card Index gray cast-iron pipe gray casting gray cataract gray catbird Gray clay treating Gray cobalt Gray cobalt Gray code Gray code Gray codes Gray codes Gray coding Gray coding Gray Collar Worker gray collie syndrome gray column gray column gray column gray column gray columns gray columns gray columns gray columns Gray component replacement

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This dinosaur sported a generally gray body, a reddish-brown, Mohawk-like crest and facial speckles, and white feathers on its wings and legs, with bold black-spangled tips.

Color palette of 150-mln yr old feathered dino shows vibrant hues by Asian News International

It was a tightly hewn thing with a gunmetal gray body, black vinyl top and tan interior.

2010 Ford Mustang Premium V-6 Convertible: Dream machine vs. N.Y. ... by The Star (Amman, Jordan)

The lid's light blue color contrasts with the white and gray body, and the instrument panel gracefully curves out from the body, making for a sturdy yet aerodynamic appearance.

The 2006 IBO Laboratory Equipment Design Awards by Instrument Business Outlook