https://doi.org/10.1351/goldbook.A00028
Logarithm of the ratio of incident to transmitted , , . This quantity is sometimes called
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: 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.