3 Reference C
Figure 18-Continued.
Section IV. OPERATION OF THEODOLITE
15. General
the theodolite is set up for actual surveying operations.
a. The instructions in this section are for the
This paragraph covers instrument adjustments.
information and guidance of the personnel responsible
for the operation of the theodolite.
b. Plate Level. Refer to figure 19 and adjust the
b. The operator must know how to perform every
plate level.
operation of which the theodolite is capable. This
section gives instructions on handling and preparation
c. Horizontal Slow-motion Screw. Refer to figure
for operation of the theodolite basic motions,
20 and adjust the horizontal slow-motion screw.
adjustments, and on coordinating the basic motions to
d. Vertical Slow-motion Screw. Refer to figure 20
perform the specific tasks for which the equipment is
and adjust the vertical slow-motion screw.
designed. Since nearly every job presents a different
e. Collimation Slow-motion Screw. Refer to figure
problem, the operator may have to vary given
20 and adjust the collimation slow-motion screw.
procedures to fit the individual job.
f. Horizontal Circle Drive. Refer to figure 21 and
16. Adjustments
adjust the horizontal circle drive.
a. General. There are two types of adjustments
g. Leveling Screws. Refer to figure 22 and adjust
made on the theodolite: instrument and operational
the leveling screws.
adjustments.
Instrument adjustments bring the
h. Horizontal Collimation Error Adjustment. Refer
theodolite into proper operating condition with respect to
to figure 23 and adjust the theodolite for horizontal
the interrelationship of its parts and are not normally
collimation error.
made in the field. Operational adjustments bring the
theodolite into proper relationship with the terrain being
i. Collimation Level. Refer to figure 24 and adjust
surveyed, and are required each time
the collimation level.
AGO 5078A 25