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iS50 ATR Module
Thermo Scientific
iS50 ATR Module User Guide
11
Table 5.
iS50 ATR Touch Point Settings
Option
Description
Measurement time
Determines the duration of scanning for a sample data
collection.
Number of scans
Shows the scans collected for the selected measurement time.
Multiple scans are averaged.
Resolution
Sets the spectral resolution of the data you collect. Typically
4 cm
-1
or occasionally 2 cm
-1
are appropriate for most ATR
applications. The smaller the resolution value, the higher
(better) is the resolution. The resolution value, along with the
measurement time, affects the number of scans.
Final format
Determines the Y-axis unit used for the collected data.
Typically set to log(1/R) or %Reflectance for ATR
applications.
Preview data
collection
Select this option if you want to collect and view (but not save)
preliminary data before the start of a sample or background
data collection. This lets you verify that your experimental
conditions are correct before collecting the spectrum.
Region
Determines the spectral range of the spectrometer that will be
used to collect the ATR data. The spectral range is defined by
the type of source, beamsplitter and detector used. One of
more of the following options may be available:
•
Mid-IR
- useful for measuring organic materials,
polymers, plastics, rubbers and many other materials.
•
Far-IR -
ideal for inorganic materials that are blended in
plastics or paints including fillers, flame retardants and
structural composites such as glass fibers. To maximize the
signal for the far-IR beam path, use
Collect > Experiment
Setup > Bench
to set
Gain
to 8.
•
NIR
- The NIR region is generally not useful for ATR
sampling because, in most cases, the depth of penetration
is too shallow to produce a usable spectrum.
Note
: Collecting data in multiple regions (must be done
sequentially) can be useful for finding differences between
compounded materials that contain fillers and other inorganic
compounds.
Max/Min
Shows the default limits of the selected detector’s spectral
range. The Max/Min limits can be reduced to eliminate
spectral regions that provide no additional information about
the sample.
