radiant exitance, $M$

Synonym: radiant emittance

Radiant power, $P$ , emitted at all wavelengths by an element of surface containing the source point under consideration divided by the area of the source. SI unit is $W m −2$ .

Notes:

Mathematical definition: $M = d P / d S$ . If the radiant power $P$ is constant over the surface area considered, $M = P / S$ .
Equivalent to the integration of the radiant power leaving a source over the solid angle and over the whole wavelength range. Mathematical definition: $M = ∫ λ M λ ⁢ d λ$ , where $M λ$ is the spectral radiant exitance at wavelength $λ$ .
Same as spherical radiant exitance. Formerly called radiant emittance.

Source:

PAC, 2007, 79, 293 (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 409

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IUPAC > Gold Book > math/physics > quantities

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Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. https://doi.org/10.1351/goldbook.

Last update: 2014-02-24; version: 2.3.3.

DOI of this term: https://doi.org/10.1351/goldbook.R05041.

Original PDF version: http://www.iupac.org/goldbook/R05041.pdf. The PDF version is out of date and is provided for reference purposes only. For some entries, the PDF version may be unavailable.

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