10 SETTING ATMOSPHERIC CORRECTION
10-56
8.3.4 視準軸之檢校
Collimation is required to make the line of sight of the telescope perpendicular to the
horizontal axis of the instrument, otherwise, it will not be possible to extend a straight line
by direct means .
z 檢驗
c Set the instrument up with clear sights of
about 50 to 60meters (160 to 200 ft.) on
both sides of the instrument.
d Level the instrument properly with the plate
level.
e Sight Point A at approximately 50 meters
(160 t.) distance.
f Loosen the vertical motion clamp only, and
rotate the telescope 180° or 200g around
the horizontal axis, so that the telescope is
pointed in the opposite direction.
g Sight Point B, at equal distance as Point A
and tighten the vertical motion clamp.
h Loosen the horizontal motion clamp and
rotate the instrument 180° or 200g around
the vertical axis. Fix a sight on Point A once
more and tighten the horizontal motion
clamp.
i Loosen the vertical motion clamp only and
rotate the telescope 180° or 200g around
the horizontal axis once more and fix a
sight on Point C, which should coincide
with previous Point B.
j If Points B and C do not coincide, adjust in
the following manner.
校正
c Unscrew the cross-hair adjustment section cover.
d Find Point D at a point between Points C and B, which should
be equal to 1/4th the distance between Points B and C and
measured from Point C. This is because the apparent error
between Points B and C is four times the actual error since the
telescope has been reversed twice during the checking
operation.
e Shift the vertical cross-hair line and coincide it with Point
D, by revolving the left and right capstan adjustment
screws with the adjusting pin.Upon completing the
adjustment, repeat the checking operation once more. If
Points B and C coincide, further adjustment is not
required. Otherwise , repeat the adjustment.
50m
A
50m
50m
50m
B
C
D
C
C
A
A
B
B
A
Eyepiece
Eyepiece
Telescope
Capstan
adjustment
screws
Capstan
adjustment
screws
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