TM 9-6650-212-12
the eyepiece focusing sleeve clockwise or counter-
Table 2-1.--Continued
clockwise in order to get the proper focus.
Para or
fig. No.
Acccpted standard
Point of inspection
b. Loosen the height adjusting collar thumb-
Legs open and close
Tripod
screw and adjust the telescope for the height
freely and the ele-
vating
thumbscrew
desired, then tighten thumbscrew.
turns without bind-
c. Loosen the rotation locking thumbscrew on
ing, Shaft rotation
a n d height adjusting
the tripod (fig. 2--1 ) and rotate the telescope for
thumbscrews lock the
the azimuth area desired, then tighten thumb-
shaft at the desired
screw.
positions.
d. Turn elevating thumbscrew so that telescope
2-7. Operation.
line-of-sight will be on target area. The telescope
a. With the telescope and tripod set up for
is now ready for observing the target area.
operation as indicated in paragraph 2-6a, turn
Section Ill. OPERATION UNDER UNUSUAL CONDITIONS
These containers can be specially made boxes, or
2-8. General.
any other reasonably airtight container with heat
In addition to the normal preventive mainte-
conducting walls. Keep them outside so that they
nance services (paras 310 through 3-12), special
will remain at prevailing temperatures until it is
care must be observed where extremes of temper-
desired to bring an instrument indoors. Then
ature, humidity, and atmospheric conditions are
put the instrument into the container, close the
present. Proper cleaning and storage not only
top, bring it indoors and let it come to room tem-
insure proper operation and functioning, but also
perature. When the box is at room temperature,
guard against excessive wear of the working parts
it may be opened and the instrument removed
and deterioration of the materiel,
without condensation forming on it. If anti-
condensation chambers are not used and instru-
2-9. Operation in Extreme Cold Weather.
ments are brought into a heated room, condensa-
tion will occur and the instruments will have to
a. In temperatures below freezing, it is neces-
be wiped thoroughly dry. Use only lens tissue
sary that moving parts be kept absolutely free
paper for drying lenses and windows.
from moisture.
b. Excessive oil on the working parts will con-
f. Inspect instruments frequently. When pos-
geal causing sluggish operation and functioning
sible, keep instruments in their cases. To provide
or complete failure. This applies in particular to
maximum protection for the instruments, the fol-
focusing parts. Special care should be taken to
lowing should be strictly observed:
eliminate all excess oil.
(1) Keep instruments thoroughly clean.
c. Do not grasp metal parts, shaft, knobs,
(2) Do not let snow and ice collect on the
sleeves, or covers with bare hands. Use gloves if
instruments.
possible, Frozen fingers or loss of skin may result
(3) Leave no metal surfaces exposed without
if this precaution is not followed.
a protective film of lubricant,
d. Never breathe on a lens in cold weather.
(4) Never apply heat from strongly concen-
Frost patterns will form obscuring the image,
trated sources directly to an instrument. Sudden
and in extreme cases, may even break the lens.
changes in temperature will cause optics to break.
e. Do not bring any materiel indoors unless it
is absolutely necessary. It is best to leave it out-
2-10. Operation in Extreme Heat or
doors, but covered to protect it from the snow.
Under Excessively Sandy or Dusty
Snowtight lockers which stay at outdoor tempera-
Conditions.
tures are recommended as a place for keeping
telescopes. If it is necessary to bring instruments
a. In hot climates, the thin film of oil necessary
from low temperatures to room temperatures,
for proper functioning will be quickly dissipated.
"anticondensation" containers should be used.
Instruments should be inspected frequently and
2-4
