Monochromator
The monochromator is included as an
important device of the optical system of an atomic absorption
spectrophotometer. The function of this
device in atomic absorption is to separate the spectral line of interest from
others spectral lines with different wavelengths emitted by the hollow-cathode
lamp. The desired spectral line is
chosen with the preferred wavelength and bandwidth by an appropriate
monochromator’s setting named grating.
A grating is a reflective surface, scored either mechanically or
holographically with parallel grooves that can be designed for different
wavelength regions. Generally, most of
the instruments are equipped with two gratings with the goal to cover a
wavelength range from 189 to 851 nm which is used in atomic absorption.