Thermo Scientific Nicolet iS50 GC-IR User Manual page 36

iS50 GC-IR Module
34 iS50 GC-IR Module User Guide
After the basis vectors have been collected, another message tells you to choose OK when
you are ready to begin sample data collection.
7. Inject a sample into the GC and start the GC run.
8. Choose OK in the GC-IR system software (or press the space bar on the computer
keyboard) to start GC-IR data collection.
Note If you are using an external trigger, GC-IR data collection will start
automatically when you start the GC run. For more information, refer to the
document that came with the external trigger cable.
As the experiment proceeds, the Gram-Schmidt profile gradually appears, left to right, in
a time response display. The Gram-Schmidt profile is a plot showing how overall spectral
intensity changed during the experiment. In the GC-IR example below, the peaks in the
Gram-Schmidt plot indicate when different compounds in the sample eluted from the
GC column, passed through the spectrometer beam path and absorbed infrared energy.
Figure 18. Gram-Schmidt reconstruction
Spectral intensity axis
The spectrum currently being collected appears in the spectral data display.
Peaks Time axis
Spectral data display
Time response display
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