STONEX R180 - VA Calibration; TILT Calibration

Stonex R180 – User Manual 39
4. Turn to Face 2, accurately aim at the same target again. Record the HA
R
.
5. Calculate the horizontal collimation error Hz:
𝐻𝑧 =
（ 𝐻𝐴
𝐿
− 𝐻𝐴
𝑅
± 180)
2
6. If
|
𝐻𝑧
|
> 8" (20 𝑚𝑔𝑜𝑛), a program calibration is required.
6.3. VA calibration
The VA calibration is a procedure necessary for calibrating VA angle, reducing Vertical Index Error.
Vertical Index Error is an error due to the fact that the telescope axis of the instrument is not
perpendicular to telescope vertical rotation axis. In the plane formed by telescope axis and the telescope
vertical rotation axis, the angle between the perpendicular line of the telescope vertical rotation axis
through the centre of the instrument and the telescope axis is the Vertical Index Error.
Determine the Vertical Index Error
1. Set up the tripod and instrument stable.
2. Power on the instrument. Precisely level the instrument.
3. In Face 1, accurately aim at a target about 100m away whose height was similar as the instrument.
Record VA
L
.
4. Turn to Face 2, accurately aim at the same target again. Record the VA
R
.
5. Calculate the vertical index errore i:
𝑖 =
(VA
L
− VA
R
− 360°)
2
6. If
|
𝑖
|
> 8" (20 𝑚𝑔𝑜𝑛), a program calibration is required.
6.4. TILT calibration
The TILT calibration is a procedure necessary for calibrating the tilt sensor.