Infrared Absorption Spectrometers

Introduction

This document describes dispersive and Fourier-transform spectrometers that are used in infrared absorption spectroscopy.

Dispersive infrared spectrometers

Common light sources are tungsten lamps, Nernst glowers, or glowbars. Dispersive IR spectrometers use a grating monochromator to select wavelengths and are commonly used when a single wavelength is desired to monitor the kinetics of a reaction or as a GC or LC detector.

Schematic of a dispersive IR absorption spectrometer

Fourier-transform Infrared (FTIR)

Modern IR instruments more commonly use Fourier-transform techniques with a Michelson interferometer.

Picture of an FTIR absorption spectrometer

Further Information

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updated 2/24/96