Advantages of FT-IR Spectrometers:

• As the absorption at all wavelengths is recorded at the similar time, this saves lot of experiment time. This is known as the multiplex or Fellgett advantage. This leads to a spectrum along with a better signal to noise (S/N) ratio in the same time as compared to a dispersive instrument.
• These are much faster and a given spectrum could be taken in less than a second.

This gives for taking multiple scans for low concentration samples and then averaging them.

• FT-IR spectrometers provide better frequency resolution and reproducibility.

• As there are no narrow slits within an FT-IR spectrometer, the energy output is much greater than in a dispersive instrument. This is referred to as the Jacquinot benefits. This also leads to a higher signal to noise ratio (S/N ratio) than the dispersive infrared spectrometers.
• In a few FT-IR spectrometers a helium neon laser is used as an internal reference. This gives an automatic calibration along with an accuracy of better than 0.01 cm^-1 and eliminates the required for external calibrations. This internal laser reference is known as Connes advantage.
• These can be simply adapted for remote use. For instance, the beam might be diverted to pass by an external cell and detector, as in GC- FT-IR
• Because of its simple mechanical design with only one moving part (the moving mirror in interferometer), there is less wearing out of the elements and therefore better reliability of the spectrometer.
• Even by the spectra of many samples can be easily run on either FT-IR or dispersive instruments; the FT-IR spectrometers are the preferred selected for samples since of higher sensitivity.