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center mark position coincides with the intersection point of the cross.
5. If the center mark always coincides with intersection point no adjustment is necessary.
Otherwise, the following adjustment is needed.
Adjustment
1. Take off the protective cover between the optical plummet eyepiece and focusing knob.
2. Fix the paper. Rotate the instrument and mark the indicated point of the center of the
optical plummet on the paper at every 90°. As illustrated: Point A, B, C, D.
3. Draw lines that attach AC and BD and mark the intersection point of the two lines as O.
4. Adjust the four adjusting screws of the optical plummet with an adjusting pin until the
center mark coincides with Point O.
5. Repeat the inspection and adjusting steps to be sure the adjustment is correct.
6. Replace the protective cover.
15.8 Laser Plummet
Inspection
1. Set the instrument on the tripod and place a piece of white paper with two
perpendicular lines under the instrument.
2. Open the laser plummet, move the paper to make the laser point coincide with the
center of two perpendicular lines..
3. Rotate the plummet to make the laser point coincide with the intersection point on the
