Metrohm NIRS XDS Process Analyzer – SingleFiber - Manual (Page 67)

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10.4.2 Reference Standardization, Transmission Pair
Reference Standardization with Transmission Pair ends uses an innovative means to adjust each
channel to a repeatable, transferable level of spectroscopic response. The fiber ends are screwed into
a fixture, the response is measured, and the signal is “normalized” using a spectral correction.
This shows the fixture. When Reference Standardizing, this
fixture holds the two single fiber ends in alignment, at a pre-
determined distance.
The optical response at the air gap is measured and stored. A
correction is applied, to bring the channel to “0 Absorbance” in
transmission, corresponding to the response of an air
reference.
This fixture is also used in Instrument Calibration.
Follow these instructions to perform Reference Standardization:
1. Screw the single fiber ends into the fixture
as shown.
The recommended convention is to screw
the source fiber (white light) into the left
side as shown. Screw the receiving fiber
into the right side, which has the large lens.
2. Tighten the fibers with the wrench
included. The part number of the wrench is
680-100-0003.
Tighten to 8 inch-lb, or 0.9Nm. (If in doubt,
use a calibrated wrench.)
3. With both fiber ends in position, cover the
center area shown in the photo to prevent
stray light from affecting the Reference
Standardization.
Do not insert the WST3Wxxx standard.
Nothing is to be placed between the fiber
ends during Reference Standardization.