Problem
Possible Cause
Solution
A spectrum contains
totally absorbing peaks.
The sample in a transmission
experiment is too thick.
Use a thinner sample.
A spectrum contains
carbon dioxide peaks that
interfere with your data.
The background spectrum is
too old.
The spectrometer is not
adequately purged.
The spectrometer is not
purged.
The spectrometer is purged
but the air dryer does not
remove carbon dioxide.
Collect a new background spectrum to
use for ratioing your sample spectra.
Make sure you are using the correct
purge gas and that purge flow rate is
adequate. Allow the system 3 to 5
minutes to reestablish purge before
collecting the spectrum.
Install an appropriate purge gas source
and optional purge kit. Contact
Thermo Electron for details.
Replace the air dryer with one that
removes carbon dioxide, or use
nitrogen to purge the spectrometer.
Contact Thermo Electron for more
information.
A spectrum contains
water peaks that interfere
with your data.
The desiccant cannot absorb
any more water vapor.
The spectrometer is not
adequately purged.
The spectrometer is not
purged.
Check the humidity indicator and
replace the desiccant and indicator if
needed.
Make sure you are using the correct
purge gas and that purge flow rate is
adequate. Allow the system 3 to 5
minutes to reestablish purge before
collecting the spectrum.
Install an appropriate purge gas source
and optional purge kit. Contact
Thermo Electron for details.
Nicolet FT-IR User’s Guide 151