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IFS 125M User Manual Bruker Optik GmbH
Glossary F
Fourier Transform Fourier Transform (FR) spectroscopy is a mathematical trans-
formation method used to convert an interferogram into an
infrared spectrum. Essentially, Fourier Transform decomposes
or separates a waveform or function into sinusoids of different
frequencies.
All these different frequencies together sum to the original
waveform. Fourier Transform identifies or distinguishes the dif
-
ferent frequency sinusoids and their respective amplitudes.
Frequency Frequency is the number of occurrences of a repeating event
per unit time. In equations, frequency is denoted by the Greek
letter
. The following equation applies to the frequency of a
wave : , with c being the phase velocity of the wave
in the respective medium, and (lambda) being the wave-
length. The wavelength is no timely but local parameter.
Any kind of time-restricted vibration process, even in the form
of a sinusoid, always represents an overlapping of several fre
-
quencies.
FT-IR The Fourier Transform InfraRed Spectroscopy is a method to
obtain infrared spectra of a sample using an interferometer. A
Fourier transform is performed on the resulting interferogram
to calculate the spectrum.
In case of an FT-IR spectrometer infrared light emitted from a
source is directed to an interferometer which modulates the
light. Leaving the interferometer the light passes through the
sample compartment (and also the sample) and is focused
onto the detector. The signal measured by the detector is
called the interferogram.
Gateway address A gateway is a kind of connecting point between different net-
works, which controls data traffic of the respective network. A
gateway address is the address of a particular gateway within
a network.
Globar An infrared source which consists of a bar made of silicon car-
bide (SIC). This bar is electrically heated and emits infrared
light.
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