Metrohm NIRS XDS Process Analyzer – DirectLight/NonContact - Manual (Page 110)

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11.6.2 Reference Standardization, Direct Light Probes
Reference Standardization with Direct Light Probes uses an innovative means to adjust to a
repeatable, transferable level of spectroscopic response. A fixture is attached to the measuring probe
and the response is measured, and the signal is “normalized” using a spectral correction.
The picture shows the fixture. When Reference
Standardizing, this fixture holds the traceable
standards, at a pre-determined distance. The
fixture is also used in Instrument Calibration.
Follow these instructions to perform Reference Standardization:
1. Reference Paddle Adjustment
When the XDS and Direct Light head starts up, the reference paddle mechanism is positioned
in the reference position which is parallel to the long side of the black internal assembly.
2. Height and signal optimisation for
Reference Standardization
Adjust the standardisation fixture to the
sample distance “h” of your preference.
The distance “h” can be between 100 to
250 mm. Measure the height according to
the picture. Hang it up and secure with the
lettered screws. Adjust until stable and
vertical. Please see figure 1.
NOTE: The reference standardization is
depending on the distance “h”. If this is
changed a new reference standardization
has to be done.
3. Place the 80% reflectance material from the standardization box in the fixture.
Do not drop the sample.
4. Adjust the fiber angle