DX4040 INSTRUCTION AND OPERATING MANUAL (E2.04)
Figure 2.
An absorbance spectrum of carbon dioxide CO
2
measured with a DX-4015
model. c(CO
2
) = 50 ppm, T = 50
o
C, absorption path length = 9.8 m.
3.2 Components of a Fourier Transform Infrared Spectrometer
Figure 3 shows the basic parts that are typical for all non-dispersive FTIR
spectrometers. A parallel, polychromatic radiation from an IR source is directed to an
interferometer. The modulated beam is reflected through the gas sample cell. Finally,
the detector detects the intensity of the infrared beam. The detected signal is digitized
and Fourier transformed by the computer resulting in an IR spectrum of the sample gas.
Figure 3.
The basic components of an FTIR spectrometer are infrared source,
interferometer, sample cell, detector, and signal and data processing unit.
Infrared
source
Interferometer
Detector
Signal and
data processing
unit
Sample
cell
15
