Metrohm NIRS XDS Transmission OptiProbe Analyzer - Manual (Page 52)

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Continue with each standard as prompted by
Vision. Insert the T02, T03, T04, and T05 as
requested, clicking “OK” at the prompts.
When all standards have been scanned, Vision
displays the message shown.
Note the file name, and the directory. This file
has been created and saved as documentation of
the photometric response of this instrument, as
of the date that IPV Setup was performed.
In Photometric Test, the response of the
instrument -- on that date in the future – will be
tested against this file created in IPV Setup.
(Photometric Test defaults to this directory, to
make it simpler to find the file.) Any change in
response will be noted.
7.1.3 Wavelength Linearization – Final Probe Position
After mounting the probes, a final Wavelength Linearization is suggested. This will not affect
Instrument Calibration, which was performed previously. The purpose of this Wavelength
Linearization is to provide the proper settings for Auto-Linearization, in the final probe position.
Auto-Linearization is used to maintain the ongoing wavelength registration of the instrument over
extended periods of use, to assure consistent wavelength registration over time. When the probe
bundles are mounted into probe barrels, or into the Vial Heater Module, there may be a slight
difference in Auto-Linearization wavelength position. (This may amount to hundredths, or a tenth or
two, of a nanometer at most, inside the monochromator. It should not affect Instrument Calibration
wavelength position at the sample plane.)
As the instrument environment varies with temperature and working conditions, the original
Wavelength Linearization – performed in the calibration fixture – may not provide the correct center
position for Auto-Linearization with probes or Vial Heater Module. Therefore we recommend a final
Wavelength Linearization with the optics set in their final positions. This will prevent the message
“Auto-Linearization Error” from occurring when it should not.
With this final step performed, Performance Test may be run with probes in their final positions, as
long as enough energy is reaching the detector bundle, and there are no light leaks which could
reduce or affect noise. This should be determined at original set-up, before operating procedures are
finalized.
Follow the steps in section 7.1.1 to perform Wavelength Linearization. This time, however, the
calibration fixture will not be used.
If using probes, Wavelength Linearization may be done using the probes with outer barrels, if