Collecting A Background Spectrum; Measuring A Liquid Sample - Agilent Technologies 4500 Series Operation Manual

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.

Measuring a liquid sample

To apply a liquid sample to the system:
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Agilent 4500 Series FTIR Operation Manual
Open the sampling device (DialPath) by rotating the arm (see
Figure 10).
The bottom window should be visible. Place a small amount of
material on the bottom window located on the DialPath base
plate. The sample window is the 2 mm diameter yellow material
held in place by the surrounding metal disk.
Ensure the sample covers the entire surface area of the bottom
window (see Figure 13).
In the case of a volatile sample, such as with fuels analysis, larger
amounts of sample can be applied without concern of leakage or
damage to the instrument, however, using the smallest possible
amount of sample will ease in the cleaning process.
Analyzing Samples
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