User's Manual

119

optical plummet) or press key[★] to switch on laser plummet,

move the white paper to make the cross in the center in the field

of view (or laser flare);

3. Turn the feet screw, make the center mark of the

plummet coincide with the cross center;

4. Rotate alidade, every turn of 90°, observe the contact

ratio of the optical plummet and cross center;

5. When rotate the alidade, the center of the optical

plummet always coincide with the cross center, there is no need

to calibrate. Otherwise you should calibrate as the following

methods.

Calibration

1. Take down the screw cover between the optical plummet

eyepiece and the focusing hand-wheel;

2. Fix the white paper with a cross, and mark the points

when the instrument rotates 90°, as the figure shows A, B, C, D

points;

3. Connect the diagonal points A、C and B、D with a straight

line, the intersection name of the two line is point O;

4. Use the calibration needle to adjust the four calibration

screw, to make the center mark of the plummet coincide with

point O;

Cross center on the ground