The error which results if the incident beam does not fall perpendicularly to the
windows of the cell, or if the cell windows are contaminated or have some other imperfection.
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 1457
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