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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.
