Wavelength selection in UV-visible spectrophotometers actually involves a series of sub-systems and optical components. This complexity results from two considerations: firstly, achieving superior good resolution, thereby minimising the effects of polychromatic radiation on absorbance and maximising the spectral features that can be observed; and secondly minimising stray light effects, which also contributes to improving the quality of absorbance measurements.

UV-Vis spectrophotometer: Light Sources | Wavelength Selector | Sample Compartment | Detector