Logarithm of the ratio of incident to transmitted
radiant power through a sample (excluding the effects on cell walls). Depending on the base of
the logarithm a decadic and Napierian absorbance are used. Symbols:
,
,
. This quantity is sometimes called
extinction, although the term
extinction, better called
attenuance, is reserved for the quantity which takes into account the effects of
luminescence and
scattering as well.
Source:
See also:
PAC, 1996, 68, 2223
(Glossary of terms used in photochemistry (IUPAC Recommendations 1996))
on page 2226
PAC, 1990, 62, 2167
(Glossary of atmospheric chemistry terms (Recommendations 1990))
on page 2169
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.
