Instruction manual

4-2
4
CHECKING AND ADJUSTMENT
4-3 Optical Plummet
(Aligning the optical axis of the plummet with the vertical axis of the instrument)
1) Checking
(1) Place the instrument on the tripod. (No
leveling is necessary.)
(2) Place a thick sheet of paper marked
with an X on the ground just below the
instrument.
(3) Looking through the optical plummet,
adjust the leveling screws to bring the
image of the X to the center of the
reticle mark
.
(4) Rotate the alidade approximately 180°.
(5) If the marked image is seen in the
same position in the center of the
reticle mark, no adjustment will be
required.
If any displacement is detected, such
as that shown in Figure, refer to the
adjustment procedure below.
2) Adjustment
(1) Using the supplied hexagonal wrench,
turn the adjustment screws to align the
X marking with position P, as shown in
the Figure. Point P is the center point of
the line connecting the X marking and
the center of the reticle mark
.
(2) Recheck, following the checking steps
(3) to (5).
P