surface emissivity


surface emissivity
the relative emissive power of a body compared to that of an ideal blackbody. In other words, the fraction of thermal radiation emitted compared to the amount emitted if the body were a blackbody. By definition, a blackbody has a surface emissivity of 1. The emissivity is also equal to the absorption coefficient, or the fraction of any thermal energy incident on a body that is absorbed.

Mechanics glossary. 2013.

Look at other dictionaries:

  • emissivity — surface emissivity …   Mechanics glossary

  • Emissivity — Em is*siv i*ty, n. Tendency to emission; comparative facility of emission, or rate at which emission takes place; specif. (Physics), the rate of emission of heat from a bounding surface per degree of temperature difference between the surface and …   The Collaborative International Dictionary of English

  • emissivity — [ē΄mi siv′ə tē, em΄isiv′ə tē] n. the relative ability of a surface to radiate energy as compared with that of an ideally black surface under the same conditions …   English World dictionary

  • Emissivity — The emissivity of a material (usually written ε or e) is the relative ability of its surface to emit energy by radiation. It is the ratio of energy radiated by a particular material to energy radiated by a black body at the same temperature. A… …   Wikipedia

  • emissivity — The giving off of heat rays; a perfect “black body” has an e. of 1, a highly polished metallic surface may have an e. as low as 0.02. * * * emis·siv·i·ty .em ə siv ət ē, .ē .mis iv n, pl ties the relative power of a surface to emit heat by… …   Medical dictionary

  • emissivity — noun (plural ties) Date: 1880 the relative power of a surface to emit heat by radiation ; the ratio of the radiant energy emitted by a surface to that emitted by a blackbody at the same temperature …   New Collegiate Dictionary

  • emissivity — /em euh siv i tee, ee meuh /, n. Thermodynamics. the ability of a surface to emit radiant energy compared to that of a black body at the same temperature and with the same area. [1875 80; EMISSIVE + ITY] * * * …   Universalium

  • emissivity — noun The energy emitting propensity of a surface, usually measured at a specific wavelength …   Wiktionary

  • Emissivity —   The ratio of the radiant energy (heat) leaving (being emitted by) a surface to that of a black body at the same temperature and with the same area; expressed as a number between 0 and 1.   ***   The property of emitting radiation; possessed by… …   Energy terms

  • emissivity — em•is•siv•i•ty [[t]ˌɛm əˈsɪv ɪ ti, ˈi mə [/t]] n. thr the ability of a surface to emit radiant energy compared to that of a black body at the same temperature and with the same area • Etymology: 1875–80 …   From formal English to slang


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