Components of FTIR Spectrometers

FTIR Spectrometers and its importance

FTIR (Fourier Transform Infrared) Spectrometers are instruments that measure the absorption, transmission, or reflection of infrared radiation by a sample. These measurements provide information about the sample’s molecular structure and composition. 

FTIR spectrometers have several components that work together to produce a spectrum. The essential components include a source, sample compartment, interferometer, detector, computer, and accessories.

• Source: The source of an FTIR spectrometer is an infrared light emitter that produces a beam of radiation in the infrared region of the electromagnetic spectrum. The most commonly used sources are Globar, a silicon carbide rod, and a mercury cadmium telluride (MCT) detector. 
• Sample Compartment: The sample compartment is a specially designed chamber where the sample is placed for analysis. It must be designed to prevent outside interference and minimize sample degradation. The sample compartment must be sealed to prevent any outside light from entering the system, and it should be purged with dry air or nitrogen to prevent water vapour from interfering with the measurement.
• Interferometer: The interferometer is the heart of an FTIR spectrometer. It separates the incoming infrared beam into its frequencies and then recombines them to produce an interference pattern that is detected by the detector. The most commonly used interferometer is the Michelson interferometer, which consists of two mirrors and a beam splitter.
• Detector: The detector is responsible for converting the interference pattern produced by the interferometer into an electrical signal. The most commonly used detectors are MCT and deuterated triglycine sulphate (DTGS). 
• Computer: The computer is an essential component of an FTIR spectrometer. It is used to control the instrument, collect and store data, and perform data analysis. The computer also controls the interferometer and detector and processes the data to produce a spectrum.

Video 01: FTIR Analysis (FTIR Spectroscopy)

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