absorption pathlength

of a sample cell
The length of the radiation path through the absorbing medium; it is equal to the cell path length, \(l\), in the case of single-pass cells at normal incidence of radiation.
PAC, 1988, 60, 1449. (Nomenclature, symbols, units and their usage in spectrochemical analysis - VII. Molecular absorption spectroscopy, ultraviolet and visible (UV/VIS) (Recommendations 1988)) on page 1453 [Terms] [Paper]