Adjustments menu

The Adjustments menu contains all the instrument collimation and calibration routines.

  • Press to scroll to Adjustments and then press .

Compensator calibration

The Trimble SPS Series Total Station is equipped with a dual axis compensator. The compensator is active when the instrument is switched on. The compensator should be calibrated periodically, to adjust for any minor changes in the instrument caused by normal wear and tear, shipping or temperature variations.

To calibrate the compensator, the instrument needs to be in perfect balance. After calibration the compensator sensor will automatically adjust and allow for changes in that balance caused by the presence or the absence of an internal battery.

To minimize imbalance in the instrument:

  • An internal battery must be present in the battery compartment.

  • The instrument handle must be attached.

  • The instrument will automatically position the telescope and distance unit for best balance.

To start the compensator calibration:

  1. Level the instrument. The instrument will automatically check if the compensator is within range before the calibration is started.

  2. Press to scroll to Compensator calib. and then press .

  3. Follow the instructions in the display:

    1. Ensure the instrument handle is installed and then press .

    2. Ensure the control unit is not installed and then press .

NOTE – Trimble recommends that you regularly carry out a compensator calibration, particularly when measuring during high temperature variations and where the highest measurement accuracy is required.

NOTE – If a compensator calibration has been performed, Trimble recommends you carry out an HA/VA and track Collimation. Performing a compensator calibration invalidates the previously stored values from the last HA/VA and Tracker collimation, so it is imperative that you carry out these collimations each time you do a compensator calibration.

The calibration process involves the instrument automatically reading the compensator value at a series of predetermined positions through the full rotation of the instrument. The process takes approximately one minute to complete. During the process the instrument should be on a stable platform, free from vibration and untouched by the user. The instrument runs through Balancing, Compensating, and displays Compensation complete! when the calibration process is done.

HA/VA collimation and Trunnion axis tilt

The instrument utilizes precise angle and distance measurements to determine the position of the point being measured. The instruments design facilitates the ability to measure all points with a single pointing to the target in the face 1 position. All electronic total stations are subject to collimation errors in both the horizontal and vertical angle measuring systems, and also errors caused by the axis of the telescope not being truly perpendicular to the vertical of the instrument.

To compensate for these errors, the collimation routine allows the operator to accurately determine the current errors in the instrument, and store the errors as corrections to be applied to all measurements made in a single pointing to a target. In this way the instrument will always provide accurate measurements:

The Collimation errors and Trunnion axis tilt will change over time, the most common changes being caused by

  • Wear and tear with use

  • Bumps and knocks during transit

  • Large changes in operating temperature

Trimble recommends that a collimation check and tilt axis check be carried out routinely as follows:

  • After any long uncontrolled transport of the instrument (e.g. after service or shipment to a new location)

  • After any accidental knock or drop

  • At any time when the operating temperature changes by more than 10° C (18 °F)

  • At any time when the instrument changes it's height above sea level by more than 500 m (1640 ft)

  • At any time when the highest accuracy positions are required

  • Routinely on a periodic basis (Monthly, weekly etc.)

  • anytime a compensator calibration is performed

Trimble also recommends that the operator keep a record of the dates and values measured so that any gross changes can easily be detected. Gross changes can indicate the need for a check by an approved service center.

When carrying out collimation error checks using controller and field software, Trimble reccomends that the user maintain a site and work Order in Trimble Field Software especially for the purpose of tracking the instrument calibration process. Trimble Field Software will store the new collimation and trunnion axis tilt values within the currently open work order. Maintaining a log of all instrument checks, helps QA and QC processes over the lifetime of the instrument.

The adjustment of the instrument for HA/VA collimation and Trunnion Axis tilt is a two-stage process.

The Horizontal and Vertical collimation and the trunnion axis tilt correction have been measured and stored in the instrument at the factory.

In all calibrations, multiple sightings will be made in both faces to ensure that any minor pointing errors can be eliminated in the accurate determination of current collimation error values.

In a new instrument the values should be close to zero, over time these will change. The instrument allows a maximum value of 0.05 grads (0.045 degrees) in the HA, VA and Trunnion axis tilt values. If these values are exceeded, the instrument will need service to rectify a mechanical problem.

  1. Press to scroll to HA/VA collimation and then press .

    The current collimation values appear.

  2. Press to scroll to one of the following:

    • Continue. Then press to continue the HA/VA collimation test.

    • Cancel. Then press C to return to the Adjustments menu.

  3. If you select Continue, press to scroll to one of the following:

    • New observation. Then press to continue the HA/VA collimation test.

    • Change face. Then press to change between face 1 and 2.

    • Cancel. Then press to return to the Adjustments menu.

      • If you select New observation:

        1. Aim accurately in face 2 towards a point near the horizon at max. ±5 grads (± 4.5 degrees) to the horizontal and at a minimum distance of 100 m (328 ft.).

        2. Press to scroll to New observation. Then Press to measure and record angles

        3. Re sight the instrument at the same point and press the enter key again. Repeat this process for a minimum of 5 sightings in face 2.

        4. Press to scroll to Change face. Then press to change to face 1.

        5. Aim accurately towards the same point as that used in face 2.

        6. Press to scroll to New observation. Then press to measure and record angles.

        7. Re-sight the instrument at the same point and press the enter key again. Repeat this process for the same number of times as in face 2.

          As observations are made on the first face (either face 1 or face 2), the angle values are stored and the counter increases. When one or more observations have been taken on each face, and the number of observations on each face are the same, the software calculates and displays the new horizontal and vertical collimation values.

  4. Press to scroll to one of the following:

    • Trunnion coll. Then press to continue to Trunnion collimation. Select Trunnion coll. to continue with trunnion axis tilt collimation, step 5 below.

    • Store correction. Then press to accept and store the new collimation values.

    • Cancel. Then press to return to the adjustments menu.

  5. Press to scroll to Trunnion coll. Then press to continue the Trunnion axis tilt test.

  6. Press to scroll to one of the following:

    • New observation. Then press to continue the trunnion axis tilt test.

    • Change face. Then press to change face.

    • Cancel. Then press to return to the adjustments menu.

      1. If you select New observation the number of observations in both faces appears:

      2. Aim accurately in face 2 towards a point at least 15 grads (13.5 degrees) above or below the point where the collimation test was made at a minimum distance of 30 m (66 ft.).

      3. Press to measure and record angles.

      4. Press to scroll to Change face. Then press to change face.

      5. Aim accurately towards the point.

      6. Press to measure and record angles.

        As observations are made on the first face (either face 1 or face 2), the angle values are stored and the observation counter increases. When one or more observations has been taken on each face, and the number of observations on each face are the same, the software calculates and displays the new trunnion axis tilt value.

  7. Press to scroll to one of the following:

    • Store correction. Then press to accept the new trunnion axis tilt value. The Adjustments menu appears.

    • Cancel. Then press to return to the Adjustments menu.

NOTE – The instrument will prohibit a trunnion axis tilt test if it is made towards a point with an angle less than 15 grads (13.5 degrees) from the point where the collimation test was made. The trunnion axis tilt determination accuracy will improve with a steeper angle towards the measured point. The minimum distance for the trunnion axis tilt measurement is 30 m (66 ft.).

NOTE – If the trunnion axis tilt correction value is greater than 0.05 grads (0.045 degrees), the message Fail Remeasure? appears. Press Yes and then repeat the measurement procedure. If the value is greater than 0.05 grads (0.045 degrees) and you answer No to the re measurement message, the instrument uses the correction value previously stored in the instrument. If the value is greater than 0.05 grads (0.045 degrees), then the instrument must be mechanically adjusted at the nearest authorized Trimble service center.

Tracker collimation

The instrument tracker unit is designed to be coaxial with the instrument cross hairs. For this reason a tracker collimation check needs to be carried out on a regular basis (under the same conditions as the HA/VA collimation check) to ensure that any slight misalignment is corrected for.

Perform the test over a similar distance as that you will be working on, but at least 100 m. The prism target must be very still during the test (Trimble recommends that you use a tripod or bi-pod mount for the target) and must be in clear line of sight without any obstructing traffic. The instrument is calibrated to accurately point at the center of the target in both horizontal and vertical axes. The calibration is used to correct the positions of all points measured using the Autolock function. The measured calibration values are stored and used until a new set of calibration values are determined.

NOTE – The adjustment between the two optical axes, i.e. the Telescope and the Tracker, may differ. See Aiming.

  1. Press to scroll to Tracker collim then press .

  2. Accurately aim towards a prism.

  3. Press to scroll to New observation and then press .

    The instrument will measure to the target in both faces automatically and then display the current values.

  4. Press to scroll to one of the following:

    • Store correction. Then press to save the correction values.

    • Cancel. Then press to return to the Adjustments menu

Once the instrument has stored the correction values, the Adjustments menu appears.

Laser pointer

The laser pointer is a visible laser that is emitted from the telescope along the line of sight. The laser is used to visibly indicate the point being measured, and is especially useful when employing the DR reflectorless EDM for measurement. The laser pointer is clearly visible in areas of shadow, inside buildings and tunnels and also at night, however in bright sunshine it is generally not readily visible with the human eye.

The following controls allow the laser pointer to be switched On and Off.

NOTE – The laser pointer is mechanically aligned to the telescope cross hairs. The laser may require periodic adjustment to keep it perfectly aligned for measurement. In order to adjust the laser pointer it has to be switched On; see The laser pointer.

  1. Press to scroll to Laser pointer then press .

  2. To change the laser pointer setting press to select Next and then press to select On or Off

  3. When you have found the setting of your choice press to select Set and then press to store this setting. You will then be returned to the Adjustments menu.

  4. If you want to cancel press to select Cancel and then press to return to the Adjustments menu.

    With the laser pointer on, you can adjust the beam. For more information, see The laser pointer.

Autofocus calibration

The instrument is equipped with an autofocus function. Before you can start using the autofocus, the function needs to be calibrated.

NOTE – This feature is not available on all models.

To start the calibration

  1. Remove the Controller from the instrument

  2. Level the instrument. The instrument will automatically check if the compensator is within range before the calibration is started.

  3. Press to scroll to Autofocus calib and press

  4. Aim and manually focus at a target / prism at a distance of at least 500 meters then press .

The instrument will show Calibrating, then Calibration completed successfully.

Back

To return to the Setup menu, press to scroll to Back... and then press .