Double Beam Spectrometers:

In a double beam spectrometer, the radiation coming from the monochromator is split within two beams along with the help of a beam splitter. These are passed concurrently by the reference and the sample cell. The transmitted radiations are detected through the detectors and the difference in the signal at all the wavelengths is suitably amplified and sent for the production.

The common arrangement of a double beam spectrometer is shown in Figure. There could be variations depending on the manufacturer, a wavelength region for that the instrument are designed, the resolutions needed etc.

Figure: Schematic diagram for a double beam spectrometer