Sokkia SRX1 Operator's Manual page 149

4. Wait a few seconds for the display to stabilize,
then read the current tilt angle in the X (sighting)
direction and Y (horizontal axis) direction.
5. Press [OK]. The top of the instrument and
telescope automatically rotate 180° and the
horizontal angle is set to 0°.
6. Wait a few seconds for the screen to stabilize,
then read the automatically compensated angles
X2 and Y2.
7. In this state, calculate the following offset values
(tilt zero point error).
Xoffset = (X1+X2)/2
Yoffset = (Y1+Y2)/2
If one of the offset values (Xoffset, Yoffset)
exceeds ±10", adjust the value using the following
procedure.
When the offset value falls within the range ±10",
adjustment is not necessary.
Press {ESC} to return to <Instr. const>.
8. Press [OK] to automatically rotate the top of the
instrument and telescope through 180°.
23. CHECKS AND ADJUSTMENTS
141