Metrohm NIRS XDS Interactance OptiProbe Analyzer - Manual (Page 31)

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Spacers are available for 2, 4, 5 and 10mm.
Note that the pathlength through the liquid
sample is 2X that of the spacer, since the energy is
transmitted through the sample to the mirror, then
back through the sample to reach the window to
carry the signal to the detectors.
The spacers give pathlengths as shown:
• 2mm spacer 4mm pathlength
• 4mm spacer 8mm pathlength
• 5mm spacer 10mm pathlength
• 10mm spacer 20mm pathlength
The reference scan is taken with the Interactance
Immersion Tip located in the lowest aperture on
the front of the instrument, as shown.
Click on the reference icon in Vision. Position the
probe fully into the aperture, to block external
sources of light.
When placing the Interactance Immersion (Liquid)
Tip into the sample, angle it slightly to avoid
trapped bubbles between the mirror end and the
sample window. Bubbles will change the spectral
readings.
Cleaning is similar to the Interactance Reflectance
end. Use a suitable cleaning solution, then rinse
with distilled water to prevent sample carry-over
from one sample to the next.