Corrections and Adjustments TCA 1800

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

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

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

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

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

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

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

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

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

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

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

ATR Collimation Error To be discussed during the ATR Topic