optical-beam error

in spectrochemical analysis
For @[email protected] 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 @[email protected] slightly higher than the true @[email protected] These errors are collectively termed optical-beam errors.
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 [Terms] [Paper]