For
wavelength-scanning spectrometers, an error may be introduced if the image position on the photodetector
changes. Reflection of the incident radiation, e.g. between the cell walls, is another
source of error and results in a measured
absorbance slightly higher than the true
absorbance. These errors are collectively termed optical-beam errors.
Source:
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