radiant exitance, \(M\)

Synonym: radiant emittance
@R05046-1@, \(P\), 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 \(\text{W m}^{-2}\).
  1. Mathematical definition: \(M = \text{d}P/\text{d}S\). If the @R05046-2@ \(P\) is constant over the surface area considered, \(M = P/S\).
  2. Equivalent to the integration of the @R05046-3@ leaving a source over the solid @A00346@ and over the whole @W06659@ range. Mathematical definition: \(M = \int_{\lambda}M_{\lambda}\, \text{d}\lambda\), where \(M_{\lambda}\) is the @S05825@ at @W06659@ \(\lambda\).
  3. Same as spherical radiant @E02264@. Formerly called radiant emittance.
PAC, 2007, 79, 293. (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 409 [Terms] [Paper]