Spectra Precision Focus 8 Series, User Manual

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2 Preparation
2 6 Spectra Precision Focus 8 Series Total Station User Guide
Centering
When you center the instrument, you align its central axis precisely over the station
point. To center the instrument, you can either use the optical plummet or a plumb
bob.
Centering using the optical plummet
Note – If you require high accuracy, check and adjust the optical plummet before you
center the instrument. For detailed instructions, see Checking and adjusting the circular
level, page 44 .
To center the instrument using the optical plummet:
1. Set up the instrument on the tripod. For detailed instructions, see Setting up the
tripod, page 25 .
2. While looking through the optical plummet, align the
reticle with the station point. To do this, turn the leveling
screws until the center mark of the reticle is directly
over the image of the station point.
3. While supporting the tripod head with one hand, loosen
the tripod leg clamps and adjust the lengths of the legs
until the air bubble is in the center of the circular level.
4. Tighten the tripod leg clamps.
5. Use the electronic level to level the instrument. For detailed instructions, see
Leveling, page 29 .
6. Look through the optical plummet to check that the image of the station point
is still in the center of the reticle mark.
7. If the station point is off center, do one of the following:
–
If the station point is slightly off center, loosen the tripod mounting screw
and then center the instrument on the tripod. Use only direct movement to
center the instrument. Do not rotate it.
When the instrument is centered, tighten the mounting screw.
–
If the displacement of the station point is major, repeat this procedure from
Step 2 .