1. Corrections and Adjustments TCA 1800

2. Errors Present in TCA (l,t) Dual Axis Compensator Index Error
(i) Vertical Index Error
(c) Line of Sight Error
(a) Tilting Axis Error
(ATR) Target Recognition Axis Error

3. These Errors Can Change Over Time
and With Temperature ...

4. Therefore Should be Redetermined:
Before the First Use
Before Each Precision Survey
After Being Transported Over Long Distances
After Long Periods of Work
Change of Temperature > 20 degrees C

5. Dual Axis Compensator Errors
This Determines the Error in the Longitudinal (l) and Transverse (t) Compensators
If the instrument is to be Leveled without Turning the Alidade, this procedure must be conducted periodically

6. Dual Axis Compensator Errors Page 2
Acclimatize the Instrument
Level the Instrument
Activate the Calibration Procedure
Select <CAL> from the Main Menu
Press <F1> (l, t)
Follow Prompts

7. Vertical Index Error
Zero Point Error of the Vertical Circle in relation to the Vertical Axis
Setup and Level the Instrument
Setup a Target at about 100 m
Make sure that the target is within 9 degrees of the horizontal plane

8. Vertical Index Error Page 2
Activate the Calibration Procedure
Select <CAL> from the Main Menu
Select <F2> (i)
The Dual Axis Compensator is automatically turned off for the process
Follow the Prompts

9. Horizontal Collimation Error
This is the Error in the Line of Sight as it deviates from the line perpendicular to the Tilting Axis
Setup and Level the Instrument
Setup a Target at about 100 m
Make sure that the target is within 9 degrees of the horizontal plane

10. Horizontal Collimation Error Page 2
Activate the Calibration Procedure
Select <CAL> from the Main Menu
Select <F3> (c)
The Dual Axis Compensator is automatically turned off for the process
Follow the Prompts

11. Tilting Axis Error
Deviation of the Tilting Axis from the Perpendicular of the Vertical Axis
Setup a Target at about 100 m
The Target must be positioned at least 27 degrees above or below the horizon

12. Tilting Axis Error Page 2
Activate the Calibration Procedure
Select <CAL> from the Main Menu
Select <F3> (a)
The Dual Axis Compensator is automatically turned off for the process
Follow the Prompts

13. ATR Collimation Error
To be discussed during the ATR Topic