Install guide

ARMY TM 5-6675-308-34
MARINE CORPS TM 08837A-34/2
of the instrument. The vertical circle level is com-
pletely built-in and is located adjacent to the vertical
circle.
(c) Collimation level tangent screw. The colli-
mation level tangent screw is located below the vertical
circle and on the same standard. This control is used for
precise leveling of the vertical circle level (split bubble)
by bringing the images of the ends to the bubble into
coincidence. A collimation level mirror on the side of
the standard is provided for viewing the position of the
bubble. Below the collimation level mirror, a hinged
collimation level reflector is rotated outward to provide
illumination of the vertical circle level.
(d) Telescope. The 28-power telescope of the
theodolite can be rotated vertically about the horizontal
axis of the theodolite. Objects appear inverted when
viewed through the telescope. The reticle of the tele-
scope is etched on glass and consists of horizontal and
vertical crosslines and stadia lines. The reticle crosslines
are focused by rotating the eyepiece; the image, by
rotating the knurled focusing ring. Three adjusting
screws are provided for correcting the horizontal colli-
mation error. A reticle illuminating mirror control knob
located on top of the telescope controls a small mirror
inside the telescope for illuminating the reticle when
electric illumination is used.
(e) Circle selector knob. The circle selector
knob is located immediately above the trademark in-
scription “Wild’. The knob is inscribed with a heavy
black line which indicates whether the image of the
horizontal or the vertical circle is visible in the circle-
reading microscope. When the line is horizontal, the
horizontal circle may be viewed; when the line is
vertical, the vertical circle may be viewed.
(f) Microscope. Attached to the telescope is a
microscope for viewing the horizontal and vertical
circles. The circle to be viewed is selected by turning
the circle selector knob to either the horizontal or the
vertical position, The field of view of the microscope
appears to contain two small windows. The upper
window contains images of two diametrically opposite
portions of the horizontal or vertical circle. One of the
images of the circle is inverted and appears above the
other image, The lower window contains the image of a
portion of the micrometer scale. The image of the scale
is brought into focus by rotating the knurled micros-
cope eyepiece.
(g) Coincidence knob. The coincidence knob on
the side of the right standard is used to obtain readings
for either the horizontal or vertical circle in conjunc-
tion with the micrometer scale. It operates the microm-
eter scale to bring the vertical or horizontal circle
graduations into coincidence.
(h) Vertical circle illumination mirror. A tilting
mirror for illuminating the vertical circle is located on
the side of the standard at the center of the vertical
5-4
circle. This mirror is identical with the mirror on the
horizontal circle in construction and use.
(i) Horizontal clamping screw. The horizontal
clamping screw is located on the right front portion of
the instrument imemdiately above the horizontal circle
housing. This control is used to lock the alidade in any
desired position on its vertical axis.
(j) Horizontal tangent screw. The horizontal
tangent screw is located on the right rear portion of the
instrument immediately above the horizontal circle
housing. This control enables precision adjustment in
the horizontal positioning of the telescope.
(k) Vertical clamping screw. The vertical
clamping screw is located adjacent to the vertical circle.
-
This control permits the telescope to be rotated verti-
cally about its axis or to be locked in a fixed vertical
position.
(l) Vertical tangent screw. The vertical tangent
screw is immediately below the vertical clamping
screw. This control permits precision adjustment in the
vertical position of the telescope.
(4) Carrying case. The carrying case for the the-
odolite consists of a base plate and steel dome-shaped
hood. When the theodolite is placed on the base plate,
it rests on three supports and is secured to the support
by three clamps. A padded wooden box is also furnished
for transporting the theodolite in its carrying case.
(5) Electric illumination device. The theodolite
contains a built-in wiring system for illuminating the
circles, the micrometer scale, and the telescope reticle.
Two bulb holders are in the base of the carrying case or
in the accessory case. Each of the circle-illuminating
mirrors can be replaced by pulling a mirror off the
instrument and inserting a bulb holder in its place. A
battery case is attached to one of the tripod legs, and
the wiring from this case leads to an illumination socket
located in the tribrach. A second wire from the battery
case leads to a hand lamp that is used for general
illumination around the instrument. A rheostat is pro-
vided on the battery case for adjusting the intensity of
light, Telescope reticle illumination is adjusted by tur-
ning the reticle illumination knob on top of the telescope
to rotate a small mirror located at the horizontal axis in
the telescope.
(6) Tripod. The universal tripod is issued with the
theodolite. This tripod has extension legs and accessory
case. The overall length of the closed tripod is 3 feet;
the etended length is 5.2 feet. The accessory case is
made of leather and is mounted on the tripod. The case
contains a plumb bob with a plug-in sleeve and a
wrench for the tripod legs. The head of the tripod is
covered with a screw-on protector cap.