GT Series: Calibrations and Adjustments

Basics of calibrations and adjustments for the GT series robotic instruments. 

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GT Series: Calibrations and Adjustments

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Tilt Offset

  • Place instrument on a stable tripod
  • Level the instrument 
  • Go to Top view by pressing the ESC key twice from the OBS screen
  • Select Configuration and select 5. Inst. Cons.
  • Select 1. Tilt offset
  • Wait for instrument to stabilize and if necessary level the instrument until values are within 10” from the center
  • Press the OK button

 

  • Instrument will turn 180 degrees (HA-R and ZA).
  • Allow for instrument to stabilize
  • Press “OK” to measure values for the new position
  • Current and New values are then displayed 
    • If the difference between new and current values: 
      • Is less than 1’ : Press the Yes button to finish calibration and to accept the new values
      • Exceeds 1’ : Repeat process
      • If the difference of new and current values is still above the 60” after repeating the process, contact your Topcon Dealer

 

Collimation

  • Place the instrument on a stable tripod
  • Level the instrument 
  • Place or find an observable target over 300ft away
  • Select Configuration and select 5. “Inst. Cons.”
  • Select 2. Collimation
  • Sight the target from the Face 1 position, and place the center of the cross hairs on the center of the target, manually.

 

  • Press the OK button to accept the HA and ZA, then instrument will turn 180 degrees Hz and Vt
  • Sight the same target again from Face 2
  • When ready to accept the HA and ZA for Face 2, press the OK button
  • The Collimation Result screen will then display the angular difference obtained from the observations
  • Press YES to accept the values and use as the new constant
  • Press NO to disregard

 

Reticle Offset

  • Place the instrument on a stable tripod
  • Level the instrument 
  • Place prism 300ft (100m) away
  • Select Configuration and select 5. “Inst. Cons.”
  • Select 3. Image Sensor – Reticle offset

 

  • Sight the target on the face 1 position and place the center of the cross hairs on the center of the prism manually. 
  • Press OK button. Instrument will proceed to measure the reflection emitted by the prism, and will measure the returning light from the reticle.
  • The New and Current Values will display.
  • Press YES to accept new values.
  • It is recommended to repeat process to accurately establish the trend for the field conditions in the moment.