Wavelength Selectors:

In spectrophotometric measurements we required to use a narrow band of wavelengths of light. This enhances the selectivity and sensitivity of the instrument. Less expensive instruments use a filter to isolate the radiant energy and give a broad band of the wavelengths. In several applications we required to continuously vary the wavelength over a defined range. This could be achieved through using monochromators.  Most modern instruments use monochromators which employ a prism or diffraction grating as the dispersing medium. The selection and use of fillers and monochromators is defined below.