double-wavelength spectroscopy

https://doi.org/10.1351/goldbook.D01854
The effect of spectral background due to impurities, solvent or radiation @[email protected] may be reduced if the difference in the absorbances of a sample measured at two selected wavelengths is obtained. This is often achieved by repetitively switching from one @[email protected] to the other. [email protected]@ @[email protected] does this automatically by allowing two beams of radiation of different wavelengths to pass through the cell. One beam is fixed at a longer @[email protected] and the other measures @[email protected] while being scanned over a limited @[email protected] range at shorter wavelengths.
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 1455 [Terms] [Paper]