emittance, \(\varepsilon\)

https://doi.org/10.1351/goldbook.E02062
Ratio of @R05041@ of a thermal radiator to that of a full radiator (black body) at the same temperature. In ISO this quantity is called emissivity.
Sources:
Green Book, 2nd ed., p. 31 [Terms] [Book]
ISO, 31-5 [Terms] [Book]
PAC, 1996, 68, 2223. (Glossary of terms used in photochemistry (IUPAC Recommendations 1996)) on page 2239 [Terms] [Paper]
PAC, 1996, 68, 957. (Glossary of terms in quantities and units in Clinical Chemistry (IUPAC-IFCC Recommendations 1996)) on page 972 [Terms] [Paper]