LI-COR LI-870, Using Manual

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Section 4.
Maintenance
Cleaning the optical bench
The LI-870 optical bench can be removed and cleaned with just a few steps if neces-
sary. Generally speaking, you shouldn't undertake this procedure unless you've
ruled out other potential problems. While the process itself is not difficult, you will
have to set the instrument zero and span after reassembling the optical bench.
An optical bench cleaning kit (part number 9980-066) is included with your LI-870
spares kit. You will also need a small Phillips screwdriver. Follow these steps to
remove and clean your optical bench and replace the O-rings. Note that the images
included in this section were taken from a prototype LI-870. The wiring and plumb-
ing in your instrument may appear slightly different.
Warning:
Be sure that you are properly grounded to avoid electrostatic discharge that
can damage the electronics. Use an anti-static wrist strap, electrostatic discharge
grounding mat, or occasionally touch bare metal that has a clear path to ground, such as
an unpainted computer case.
1
Unplug your instrument from the Smart Chamber or LI-8250. If you've been operating the instru-
ment recently, you should allow the optical bench to cool down to room temperature.
2 Open the analyzer and remove the plate covering the optical bench.
4-1 Using the LI-870 CO₂/H₂O Analyzer