MS Series total station field calibration procedures

This article explains how to perform field calibrations with an MS Series robotic total station.

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MS Series total station field calibration procedures

Environmental condition requirements for performing adjustments

Set up the instrument on a stable and solid surface.​ Do this in calm weather conditions and with a clear line of sight.​

You should have a clear view to a building corner or other stable and well-defined target at a distance greater than 100 meters (328 ft).

Keep a distance of 50 meters (164 ft) between the instrument and the prism.​

Make sure there are no reflective or shiny objects in front of or behind the instrument.​

Level the instrument

Confirm the instrument is set up in a solid and stable location.

Level the instrument to within 20" (seconds) on both the X and Y axes.

Instrument constants

Perform the following procedure to cancel the tilt zero-point error:

  1. Press the Star key on the instrument control panel.
  2. Select the Settings icon.
  3. Select Inst.cons (option 3).

The three instrument constants to calibrate are:

  • Tilt offset​
  • Collimation​
  • Image Sensor-Reticle offset​

Tilt offset

If the tilt angle shown on the display shifts from tilt angle 0° (zero point), the instrument is not correctly leveled. This will adversely affect angle measurement.​

Perform the following procedure to cancel the tilt zero-point error:

  1. Press 1.Tilt offset.
  2. Press OK for the first tilt measurement for face 1.

The instrument will rotate to face 2 automatically.

Once on face 2, press OK for the second measurement of the tilt bubble.

The results are displayed​.

Press Yes to accept and apply the results or No to repeat the process.

Tilt offset results

Check the results for the tilt zero-point error​:

X offset = (X1+X2)/2​

Y offset = (Y1+Y2)/2​

If one of the offset values (X offset, Y offset) exceeds ±10" (seconds), adjust by pressing Yes​.

When the offset value falls within the range ±10" (seconds), adjustment is not necessary.


If an instrument error relating to angle measurement occurs, this will adversely affect angle measurement. Performing collimation can eliminate the angle error between faces 1 and 2.

Perform the following procedure to correct the collimation offset constant:

  1. Press 2.Collimation​.
  2. Sight a building corner or a permanent and well-defined target to observe in face 1 and face 2.
  3. On face 1, sight the crosshairs precisely over the point selected for the target, and press OK.
  4. On face 2, sight the crosshairs precisely over the point selected for the target, and press OK.
  5. Press Yes to accept the values.

Collimation result

  • EL: Error of line-of-sight perpendicularity of horizontal axis and vertical axis​
  • V Offset: Zero-point offset perpendicularity of horizontal axis and line of sight​

Press Yes to accept and apply the results, or press No and repeat the process.

Image sensor-reticle

The internal image sensor is used for automatic sighting. The offset value is set to correct the position of the image sensor in relation to the telescope reticle. If the telescope reticle and image sensor become misaligned, automatic sighting of the center of the prism cannot be performed correctly and will adversely affect angle measurement. Check and adjust as outlined below:

  1. Sight the prism, and press OK.
  2. Sight the prism, and press OK.

Results are displayed.

Image sensor-reticle offset result

The Current H and Current V are the values of the last adjustment, currently saved in the instrument's memory.​

The New H and New V are the results of the new measurements.

If accepted, these values are stored in the instrument's memory.

Press Yes to accept and apply the results, or press No and repeat the process.

For more information, please refer to the Instruction Manual, Section 22: Checks and Adjustments.