Perpendicularity Of Line Of Sight To Horizontal Axis - Pentax R-2500DN Series Instruction Manual

12.4 Perpendicularity of line of sight to horizontal axis

[Checks]
① Position a target Point A at a distance 30m - 50m away from the instrument, and sight it
with the telescope.
② Loosen the telescope lock screw and turn the telescope until a point is sighted at a distance
roughly equal to that of Point A. This is Point B.
③ With the telescope still reversed loosen the horizontal lock screw and rotate the instrument
around the vertical axis, and sight Point A again.
④ Loosen the telescope lock screw and turn the telescope until a point is sighted at a distance
equal to that of Point B. This is Point C.
⑤ No adjustment is necessary if Point B and C are aligned.
[Adjustments]
① If Points B and C are not aligned, mark Point D at 1/4 the length of the BC, from Point C
in the direction of Point B.
② Using the adjustment pin, rotate the reticle adjustment screws horizontally opposite each
other (see preceding page), and move the reticle to sight Point D.
③ Repeat the check and make sure the adjustment is correct.
30-50m
①
③
A
30-50m
B
②
②
C
④
D
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