10-7 Optical Plummet
Checks
qSet the instrument on the tripod, and place a piece of white paper with a
cross drawn on it right under the instrument.
wLook through the optical plummet, and move the paper so that the intersecting
point of the cross comes to the center of the field of view.
eAdjust the leveling screws so that the center mark of the optical plummet
coincides with the intersecting point of the cross.
rRotate the instrument around the vertical axis. Look through the optical
plummet each 90°of rotation, and observe the center mark position against
the intersecting point of the cross.
tIf the center mark always coincides with the intersecting point, no adjustment
is necessary.
Adjustments
qIf the center mark does not coincide with the intersecting point, rotate the
optical plummet focusing knob cover and remove it.
wMark the point set on the line of sight at each step of 90°on the white paper
and call them A, B, C and D.
eJoin the opposed points (A,C and B,D) with a straight line, and set the
intersecting point 0.
rTurn the four optical plummet adjusting screws with a adjusting pin so that the
center mark coincides with the intersecting point 0.
tRepeat from r, and check that adjustment is correct.
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10 CHECKS AND ADJUSTMENTS
Adjusting screws
PENTAX R-300 (p65-88) 10/30/02 11:11 AM Page 72