SHANGHAI ESURVEY GNSS CO., LTD.
19
4. Turn the eyepiece cover of the reticle counterclockwise, and remove the cover to
expose the cross recessed pan head screws-fixing screws (M2.5X8) that fix the
eyepiece:
5. Use a cross screwdriver to slightly loosen the four M2.5X8 screws that fix the
eyepiece.
6. Turn the eyepiece end until the vertical line of the reticle overlaps with point A:
7. Tighten the four M2.5X8 screws that fix the eyepiece.
8. Repeat calibration until point A always moves along the vertical line of the reticle.
After doing correction for the vertical line of the telescope reticle, check the collimation error
and index error of the instrument.
5.6
Check and Adjust the Line-of-Sight Error or Collimation Error
The line-of-sight error or collimation error (C) is the deviation from the perpendicular
between the tilting axis and the line of sight, and it affects the horizontal angle readings and
increases with steep sightings. When the error is greater than 8'', adjustment of the
collimation error is required.
These errors should be determined before the instrument is used for the first time, before
precision surveys, after long periods of transport, before and after long periods of work, and
if the temperature changes by more than 10°C (18°F).
To adjust the line-of-sight or collimation error, do the following:
1. Set the instrument on the tripod or the calibration stand, and precisely level it.
2. Enter angle measurement after powering on the instrument.
3. Aim at the first target A, and press
0SET
twice to set the horizontal reading of target
A as 0°00'00".
4. Aim at the second target B. The horizontal angle to target B shows (HA1).
5. Rotate the instrument 180°.
6. Repeat step
3
-
4
. The horizontal angle to target B shows again (HA2).
7. Calculate the collimation error:
C = (HA1 - HA2 ± 180°) / 2
8. Judge if the error is within the allowable range:
o
If it is less than or equal to 8'', no adjustment is required.
o
If it is greater than 8'', proceed to step
9
-
11
.
