Install guide

ARMY TM 5-6675-308-34
MARINE CORPS TM 08837A-34/2
Figure 5-3. Horizontal Circle Readings
e. Read the horizontal circle. The reading should
be 0.150 (within ±0.100 roil), With care, a circle
may be set to an accuracy of 0.010 mil.
5-7. Pointing the Theodolite.
a.
b.
c.
d
e.
Release the horizontal and vertical clamping
screws.
Aim the telescope on the target. Focus as neces-
sary.
When the telescope crosshairs are on the target,
tighten the horizontal and vertical clamping
screws.
Use the telescope focusing ring to bring the
image into sharp focus.
Use the horizontal and vertical tangent screws to
exactly center the intersection of the horizontal
and vertical crosshairs over the target. If the
target is a vertical line, like a pole, the same
point on the target must be used for each sight-
ing.
5-8. Autoreflection. (See figure 5-4.)
a.
b.
c.
d
NOTE
To increase visibility, color the theodolite
sight white with typewriter correction
fluid. At night, illuminate the sight with
the theodolite handlamp.
Level the porro prism using the level adjust
knob and level vial. The level adjustment can
accommodate slopes up to ±20 degrees.
Aim the theodolite so the horizontal crosshair
lies along the centerline of the prism.
Increase the telescope focus towards infinity un-
til the reflected image of the front of the tele-
scope is visible.
Adiust the theodolite so the reflected image of
the theodolite sight is centered on the vertical
crosshair. See figure 5-5. Lock the clamping
screws and readjust as necessary.
5-9. Measuring Horizontal Angles. (See figure 5-8.)
a. With the telescope in the direct (D) (sight on
top) position, point the telescope on the azimuth
target.
b. Set the horizontal circle to approximately 0.150
roil.
5-8