Nikon NPL-632, Инструкция по эксплуатации

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6 Checking and Adjustment
148 Field Station NPL-632 Instruction Manual
Zero Point Errors of Vertical Scale and Horizontal Angle Corrections
Checking
1. Set up the instrument on the tripod.
2. Follow the leveling procedures described in Leveling, page 17 .
3. Flip the telescope to the Face-1 position.
4. Sight a target that is within 45° of the horizontal plane.
5. Read the vertical angle from the VA1 field in the Basic Measurement Screen
(BMS).
6. Rotate the instrument 180° and then flip the telescope to the Face-2 position.
7. Read the vertical angle from the VA2 field.
8. Add the two vertical angles together, VA1 + VA2.
–
No adjustment is required if the zero reference for vertical angles (VA
zero setting) is set to Zenith, and VA1 + VA2 equals 360°.
–
No adjustment is required if the zero reference for vertical angles (VA
zero setting) is set to Horizon, and VA1 + VA2 is either 180° or 540°.
–
An adjustment is required if VA1 + VA2 is not one of the values listed
above.
Note – The difference between the vertical angle reading the relevant angle (either
360° for Zenith, or 180° or 540° for Horizon) is called the altitude constant .
Adjusting
There are two steps in the calibration program. Usually you only complete the first
step that is described below, because the trunnion axis is finely adjusted mechanically.
To make a major adjustment to the trunnion axis error compensation, however, you
can complete the second step that is described below and make three sets of
observations.
To set the parameters for trunnion axis error compensation, establish
two targets at a horizontal distance of at least 30 m from the
instrument. The first target should be placed on the horizontal plane
and the second should be more than 30° above the horizontal plane.
Before you set the trunnion axis compensation value, you must
complete three sets of F1/F2 observations to these two points.
Even if you complete the second step, the instrument cannot store a
trunnion axis error compensation of more than 30". If the error is more
than 30", the instrument needs a mechanical check.
First
Second
target
target