l Check 1) Coincide the center mark and the point. (See Chapter 2 “PREPARATION FOR MEASUREMENT”.) 2) Rotate the instrument 180° or 200g around the vertical axis and check the center mark. If the point is properly centered in the center mark, adjustment is not required. Otherwise, adjust in the following manner. l Adjustment 1) Take off the adjustment section cover of the optical plummet telescope eyepiece. This will expose four capstan adjustment screws which should be adjusted with the accessor

[HOLD] is to fix vertical angle to the prism position even updown the telescope position, and [FREE] is to gear vertical angle to the updown of telescope movement. In case following the vertical angle to the movement of telescope, SD(Slope Distance) and VD(Vertical Distance) will be changed according to the movement of telescope. Occ. Point Operating procedure Operation Display 1 Press [F6](MORE) key from programs menu to get to the next page of programs. 2 Press [F2](OFFSET) key. 3 Press [F1](A

To ensure a precise angle measurement, tilt sensors must be turned on. The display can also be used to fine level the instrument. If the (TILT OVER) display appears the instrument is out of automatic compensation range and must be leveled manually. l GTS-820A series compensates both the vertical angle and the horizontal angle readings due to inclination of the standing axis in the X and Y directions. l For more information about dual axis compensation, see Chapter “APPENDIX” “Dual Axis Compensat

General Handling Precautions Before starting work or operation, be sure to check that the instrument is functioning correctly with normal performance. Do not submerge the instrument into water. The instrument can not be submerged underwater. The instrument is designed based on the International Standard IP54, therefore it is protected from the normal rainfall. Setting the instrument on a tripod When mounting the instrument on a tripod, use a wooden tripod when possible. The vibrations that may o