Install guide

ARMY TM 5-6675-308-34
MARINE CORPS TM 08837A-34/2
Figure 5-6. Measuring Horizontal Angles
Verify the telescope is properly pointed on the
target and record the horizontal circle reading
(0.158 mil).
With the telescope in the direct (D) position,
turn it in a clockwise direction and autoreflect
on the porro prism. Record the horizontal circle
reading (824.376 mils).
Plunge the telescope to the reverse (R) (sight on
bottom) position.
Autoreflect on the porro prism and record the
horizontal circle reading (4024.372).
With the telescope in the reverse (R) position,
point on the azimuth target, Record the horizon-
tal circle reading (3200.156).
Subtract the direct reading on the target from
the direct reading on the porro prism to obtain
the direct angle (DA).
824,376
-0.158
DA = 824.218
Subtract the reverse reading on the target from
the reverse readin on the porro prism to obtain
the reverse angle (RA).
4024.372
-3200,156
RA = 824.216
j. If DA and RA differ by more than 0.1 mil, check
the plumb and level of the theodolite and target
and remeasure the angles, If there is a consistent
error, adjust the instrument in accordance with
paragraph 5-14.
k. Mean DA and RA to obtain the horizontal angle
(HA).
824.218
+824.216
1648.434
÷2
HA =
824.217
5-10. Taking Down the Theodolite. When observations
are completed at a station, the theodolite and tripod are
taken down as follows:
a.
b.
c.
d.
e.
Place the telescope in a vertical position with
the objective lens down and tighten the vertical
clamping screw.
Turn each leveling screw to the same height.
Position the horizontal clamping screw directly
over one of the leveling screws and tighten it.
Grasp the instrument by its right standard and
unscrew the instrument-fixing screw. Lift th
theodolite from the tripod and secure it in the
carrying case. Replace the dome-shaped cover.
Replace the tripod head cover. collapse the tri-
pd, and strap the tripod legs together.
5-10