Collecting A Background Spectrum - Agilent Technologies 4500 Series Operation Manual

Analyzing Samples
ZnSe is relatively chemically-resistant to materials with a pH range between 4
CAUTION
and 9, but there are some materials, such as strong acids or heavily basic
materials, that can harm ZnSe. Avoid having materials in contact with the ZnSe
window that are outside of this recommended pH range.
Do not break the spectrometer seal and attempt to clean interior surfaces.
CAUTION
Breaking the seal will void the warranty.

Collecting a background spectrum

To ensure accuracy of the measurement, it is recommended that the
system is configured in the software to collect a background
spectrum before every sample is analyzed. This provides a baseline
profile of the system conditions with no sample loaded on the
instrument. By collecting a background automatically before each
sample measurement, negative effects of changes in the environment
can be avoided.
For detailed software instructions for collecting a background, refer
to the MicroLab Software Operation Manual.
To ensure an accurate background spectrum is collected, perform a visual
CAUTION
inspection of the ZnSe window surfaces looking for any haze or film present on
the windows from measuring the previous sample. If a film is observed, repeat
the cleaning procedure above until the window surfaces are clear of any residue.
26 Agilent 4500 Series FTIR Operation Manual