Thermo Electron Nicolet 380, User Manual

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Note The maximum intensity of a mid-IR single-beam spectrum is
typically found near 2,000 cm
-1
.
▲
Note If the distance from the baseline to 0 is greater than 20% of the
spectrum’s maximum intensity value, the detector electronics may
be overloaded. Contact Thermo Electron Technical Support for
assistance.
▲
The distorted signal may cause problems with photometric accuracy.
For good quantitative data, the sample and background
interferograms should be about the same size. Scattering samples
and very dense samples produce very small signals that, when
compared with much larger background signals, can distort
quantitative data.
Check the background and sample interferograms. If you see a
substantial difference in their sizes, photometric accuracy could be a
problem.
In some cases, system performance improves if you use a
bandwidth-limiting filter or energy screen. Filters improve the
signal-to-noise ratio of the data and also prevent detector saturation
by allowing only energy in your particular area of interest to pass to
the detector element. Energy screens help prevent detector saturation
and signal distortion. See the next section for more information
about using energy screens.
The filter or screen that you should use for your application depends
on the samples being measured and other experimental conditions.
Try using various filters or screens to determine which give the best
results for your application.
View “Optical filters” or “Energy screens” in the “Installing new
hardware” book in Spectrometer Help Topics for instructions.
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