5
The Sample Analysis Process
The normal instrumental process is as follows:
1. The Source:
Infrared energy is emitted from a glowing black-body source. This beam passes
through an aperture which controls the amount of energy presented to the sample (and, ultimately,
to the detector).
2. The Interferometer:
The beam enters the interferometer where the “spectral encoding” takes
place. The resulting interferogram signal then exits the interferometer.
3.
The Sample:
The beam enters the sample compartment where it is transmitted through or reflected
off of the surface of the sample, depending on the type of analysis being accomplished. This
is
where specific frequencies of energy, which are uniquely characteristic of the sample, are absorbed.
4. The Detector:
The beam finally passes to the detector for final measurement. The detectors used
are specially designed to measure the special interferogram signal.
5. The Computer:
The measured signal is digitized and sent to the computer where the Fourier
transformation takes place. The final infrared spectrum is then presented to the user for
interpretation and any further manipulation.