Metrohm NIRS XDS Process Analyzer – MicroBundle - Manual (Page 36)

34 ▪▪▪▪▪▪▪
6
Installation of Fiber Optics
Fiber optic cables are quite rugged, and are jacketed to protect the delicate optical fibers within.
While protected, the fiber bundles are still somewhat fragile when not handled correctly. Always use
care when routing and installing fibers.
The fibers are installed on the instrument, and are shipped in a coiled
position in the shipping container.
Handle very gently when moving and lifting, to avoid damage. Follow
these guidelines:
1. Never bend in a radius of less than 6” (153mm).
2. Never pull on the fiber bundle, as this can stress the fiber and cause breakage of individual
strands.
3. Avoid any impact or abuse of the fiber bundles.
4. Do not leave the fiber optic cable unsupported. Any motion in the cable during scanning may
cause minor variations in spectral response, due to slight differences in the internal reflection
at different bend angles. While this effect is quite small, it can cause the error of prediction to
increase slightly.
5. Never scratch or mar the polished ends of the fibers.
Cable Tray:
Due to the intrinsic safety and resistance to inductance of the fiber bundles,
these fibers can be installed in commercially available cable trays. This method
of fiber installation is preferable due to the fact that the fiber is not exposed to
a constrictive environment, as is the case with conduit. Therefore, it is less
likely that an individual fiber will break when being installed in a cable tray.
The fiber may be installed in a “ladder tray” with supports every 4-6 inches (100-150mm). Note the
minimum fiber bend radius as mentioned above. A solid-bottom tray may also be used. Tray material
may be metal, fiberglass, or any other material that does not react with the jacketing material.
The “Channel” number for a given fiber bundle (or
pair, if Transmission) may be determined by
checking where the “return” fiber is screwed in to
the multiplexer.
The channel numbers are stamped into the sheet
metal, but are quite difficult to read. This photo
shows the channel positions.
Position #10 is the internal reference fiber, from
position #10 on the lamp box. The fiber at the
center takes the light to the monochromator box.
Tightening torque is 8 in-lb (0.9Nm). Do not exceed
the recommended torque.