Universal ATR Sampling Accessory User’s Guide . 11
Contamination Check
The surface of the crystal must be clean before a measurement is taken. The contamination
check can be used to ensure this. If the crystal is not properly cleaned, negative bands in the
spectra may be observed.
Cleaning the crystal
Once data has been collected, the crystal should be cleaned.
The surface of the crystal can be cleaned with a cotton-bud moistened with pure water or a
pure organic solvent. The liquid should not be allowed to evaporate, but should be removed
with a clean, dry cotton-bud.
Take care not to scratch the surface of the crystal. Ensure the crystal is completely dry
before re-use.
A PVC “apron” (L1601856) is provided, that protects the top and front of the accessory when
cleaning with solvent.
Performing a Contamination Ready Check
NOTE:
For information about setting up Ready Checks, see the Spectrum on-screen Help.
The following description assumes that Ready Checks are already set up and
enabled.
To perform a Contamination Ready Check:
1.
From the Measurement menu, select the Instrument Checks sub-menu and then
Contamination
from the Ready Checks available.
The Ready Checks dialog is displayed.
2.
Make sure that you have removed any sample from the UATR and cleaned the crystal,
and then click
Scan
.
A new background spectrum is collected, compared to the reference background
spectrum (a spectrum taken when the crystal is known to be totally clean), and the
result of the test displayed.
3.
If required, click the link that enables you to see a print preview of the Instrument
Ready Checks Report.
