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35. CHECKS AND ADJUSTMENTS
7. Check the adjustment by rotating
the upper part of the instrument.
The survey point should remain
centered in the reticle. If
necessary, repeat the adjustment.
8. Remove the optical plummet knob
cover, and install the optical
plummet reticle cover on the
inside.
Replace the optical plummet knob
cover.
Do not over-tighten the 4 adjusting screws as this may cause the reticle to go out
of adjustment.
The additive distance constant K of the CX is adjusted to 0 before delivery.
Although it almost never deviates, use a baseline with a known distance precision
to check that the additive distance constant K is close to 0 several times a year
and whenever the values measured by the instrument begin to deviate by a
consistent amount. Perform these checks as follows.
• Errors in setting up the instrument and reflective prism or in sighting the target
will influence the additive distance constant. Be extremely careful to prevent
such errors when performing these procedures.
• Set up so that the instrument height and the target height are identical. If a flat
place is not available, use an automatic level to make sure the heights are
identical.
35.6 Additive Distance Constant