Problem
Possible Cause
Solution
System does not scan.
Laser is flickering.
Click laser indicator on Diagnostic
tab of Experiment Setup dialog box
to check laser operation. Call
Thermo Electron for assistance.
The system scans
normally but gives very
low signal intensity.
The spectrometer is out of
alignment.
The moving mirror velocity is
set too high.
There is no interferogram.
The beam path is obstructed.
The aperture is set incorrectly
on a Nicolet 6700.
Continued on next page...
Align the spectrometer using the
Align button on the Diagnostic tab
of the Experiment Setup dialog box.
Set Velocity on the Bench tab of the
Experiment Setup dialog box to a
lower velocity.
If the Source status indicator is off,
click the source indicator on the
Diagnostic tab of the Experiment
Setup dialog box to check the source
current and voltage. If the Source
indicator is on, check the
interferogram on the Bench tab of
the Experiment Setup dialog box; if
the interferogram is not present,
check the beam path and detector.
Remove the obstruction.
Check the Aperture parameter on the
Bench tab of the Experiment Setup
dialog box. For an MCT-A, MCT-B,
InSb, PbSe, Si, or InGaAs detector,
set Aperture to 32. For a DTGS
detector, set Aperture to 100.
Nicolet FT-IR User’s Guide 141