25
Screw C
Screw B
Screw A
③
Turn around the instrument 90°again. Repeat
above steps until the bubble remains in the center
of the plate level even though the instrument is
rotated to any position.
4.2.2 Using centering device to center
1)
Set up the tripod;
①
Open the tripod. Make sure that the three feet of
the tripod are approximately equal in distance
from the center and that the top is leveled. Screw
up the three locking screw;
②
Make sure that the center of the tripod top is right
above the station;
③
Stamp one foot on the ground with your feet.
2)
Install the instrument gently on the top of the tripod
and screw up the screw connection. Open the laser
plummet through star (
★
) key to aim at the station
precisely;
3)
Using circular level to level the instrument coarsely;
4)
Using tubular level to level the instrument precisely;
5)
Precise centering and leveling;
According to the observation of center device, loose the
connection screw slightly and shift the instrument horizontally
(mention that do not turn around the instrument)until the
