wavelength error

in X-ray emission spectroscopy
https://doi.org/10.1351/goldbook.W06663
The error in @[email protected] which may occur if there is a difference between the (mean) @[email protected] of the radiation entering the sample cell and the indicated @[email protected] on the @[email protected] scale.
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 1456 [Terms] [Paper]