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11. Adjustments and Corrections
The instrument is under strict test and calibration, the quality is
accord with the standard demand. But after a long-distance
transportation and environment change, the small change of
instrument parameter is inevitable. Therefore, the new purchased
instruments should be checked and calibrated before surveying to
ensure the precision.
11.1 Tubular Level
Check
See reference in
using tubular level to level the instrument
Calibration
1. In the calibration, if the level bubble diverges from the center,
use the foot spiral which parallels the leveling tube to adjust to make
the bubble move half of the distance to the center. For the remaining,
use the calibration needle to turn the level calibration screw (in the
right of the water-level) to adjust the bubble to the center;
2. Turn the instrument 180° to check that whether the bubble is
in the center. If the bubble is not centered, repeat step 1 until the
bubble is in center;
3. Turn the instrument 90° and use the third foot screw to adjust
the bubble to the center;
4. Repeat the steps of checkout and calibration until the bubble
in the center in every direction.
11.2 Circular Level
Check
After the level tube is calibrated correct, if the circular level
bubble also in center, so there is no need to calibrate.
Calibration
If the bubbles is not in the center, use the correction needle or six
angle wrench to adjust the correction screw which under the bubble to
make the bubble to the center. For calibration, you shall first loosen
the calibration screw (1 or 2) which opposite to the direction of the
bubble offset, then tighten the other correction screw in the offset
direction to make the bubble in the center. When the bubble is in
center, make sure the fastening force of the
Three calibration screws are consistent.
