### Step 4: Calibrate the Laser Probe

The calibration process described in this step may vary depending on the "Measure Laser Probe Options" and the type of installed interface. Refer to the "Measure Laser Probe Options" topic for detailed information on calibration options.

Calibrating Perceptron Probes

Note: When calibrating, PC-DMIS will override your current exposure and gray sum values with the default exposure and gray sum values detailed in the "Exposure and Gray Sum Settings During Calibration" topic. Once calibration finishes, the software will restore your original values.

The following steps outline the procedure that would be used when you are first calibrating your laser probe:

1. Select the tip that you defined in Step 3 from the Active Tip List box from the Probe Utilities dialog box.

2. Click Measure from the Probe Utilities dialog box. This opens the "Measure Laser Probe" dialog box.

3. Select the Type of Calibration Operation and then select Offset for Perceptron probes.

4. Select other calibration options as needed: Motion type, Move Speed, Parameter Sets and Calibration Tool.

Note: If using a multi-sensor CMM, the sphere location for the laser calibration tool should first be found with a calibrated touch probe so that the laser probe measurement data will be correlated with the touch probe calibration.

5. Click Measure to begin the calibration procedure. Follow any on-screen instructions. The first several prompts that you see are identical to the setup procedure for touch trigger probes.

Note: If you are using MAN or MAN + DCC Motion or you answer Yes to the message “Has the sphere moved” you will need to manually bisect the qualification sphere. See "Manually Bisecting the Calibration Sphere". Once you do an Offset calibration, you will no longer be asked to bisect the sphere unless you answer yes to the message “Has the sphere moved”.

6. For DCC Perceptron sensors, certain probe tip angles may result in the laser beam falling on a portion of the gauge stem. In some cases, the standard deviation for the probe calibration of those tips exceeds the expected amount. In those cases, PC-DMIS will display a message asking if you want to repeat the calibration of those tips. If you click Yes to repeat the calibration of the affected tip(s), the system uses the offsets and orientation determined by the first measurement instead of using the theoretical values. This results in a clipping around the target that is more accurate during this re-calibration.

7. Once execution finishes, PC-DMIS returns to learn mode and shows the Probe Utilities dialog box.

8. Steps 9 through 14 are for Metris probes only. If you are calibrating a Perceptron probe, skip to step 15.

9. Select the tip that you have just calibrated from the Active Tip List box from the Probe Utilities dialog box.

10. Click Measure to begin sensor calibration.

Important: If your CMM is equipped with a jog box (pendant) that has a variable speed control, ensure that it is set to 100% at the start of the Sensor calibration and throughout the entire Sensor calibration procedure. Failure to do this will cause an inaccurate velocity map to be calculated.

11. Select the DCC Motion option and the Sensor option from the Measure Laser Probe dialog box.

12. Verify that the same Calibration Tool that was used for tip calibration is selected.

13. Click Measure. The sensor calibration procedure is much longer than Tip calibration and will take at least 5 minutes.

14. Once Sensor calibration finishes PC-DMIS shows the Probe Utilities dialog box.

15. If needed, click Add Angles to define any other tip angles that need to be calibrated.

16. Select any tips from the Active Tip List box from the Probe Utilities dialog box for which you would like to perform tip calibrations. The initial tip calibration only found offset information for the probe configuration.

17. Click Measure to begin tip calibration for all selected angles. If no angles are selected, you will be prompted to see if you want to calibrate all tips.

18. Select the Tips option from the Measure Laser Probe dialog box.

19. Verify that the same Calibration Tool that was used for tip calibration is selected.

20. Click Measure. PC-DMIS performs tip calibration and shows the Probe Utilities dialog box when it is finished.

Note: Offsets of each axis for Perceptron Sensors are saved in the registry as HotSpotErrorEstimateX, HotSpotErrorEstimateY, and HotSpotErrorEstimateZ.

Note: Once either Offsets or Sensor calibration has been performed, depending on probe type, only steps 14 through 19 need to be performed on any new probe file which utilize the same sensor and CMM.

Calibrating Portable CMS Laser Probes

The following steps outline the procedure that would be used when you are calibrating a portable laser CMS probe using a planar artifact:

1. Click Measure from the Probe Utilities dialog box. This opens the Measure Laser Probe dialog box. See "Measure Laser Probe Options".

2. Select the appropriate sensor mode. The default is Zoom2A.

3. Place the planar artifact in a convenient location for the arm to measure.

4. Click Measure to begin the calibration procedure. Follow any on-screen instructions.

Note: The calibration procedure will require 17 stripes to be acquired on the planar artifact. These stripes will be captured by the laser in different positions and orientations with respect to the planar artifact.

For each stripe to be acquired, the system will draw a yellow target line on the live view, to help you visualize where the acquisition needs to be taken.

Calibrating DCC CMS Laser Probes

The calibration process described in this step may vary depending on the laser probe options and the type of installed interface. Refer to the "Measure Laser Probe Options" topic for detailed information on calibration options.

The following steps outline the procedure that would be used when you are first calibrating your laser probe:

1. Select the tip that you defined in Step 3 from the Active Tip list from the Probe Utilities dialog box.

2. Click Measure from the Probe Utilities dialog box. This opens the Measure Laser Probe dialog box.

3. Select the appropriate sensor mode. The default is Zoom2A.

4. Select other calibration options as needed: Motion type, Move Speed, Parameter Sets and Calibration Tool.

Note: If using a multi-sensor CMM, the sphere location for the laser calibration tool should first be found with a calibrated touch probe so that the laser probe measurement data will be correlated with the touch probe calibration.

5. Click Measure to begin the calibration procedure. Follow any on-screen instructions. The first several prompts that you see are identical to the setup procedure for touch trigger probes.

Note: If you are using MAN or MAN + DCC motion or you answer Yes to the message “Has the sphere moved”, you will need to manually bisect the qualification sphere. See "Manually Bisecting the Calibration Sphere".

6. Once execution finishes, PC-DMIS returns to learn mode and shows the Probe Utilities dialog box.

7. If needed, click Add Angles to define any other tip angles that need to be calibrated.

8. Select any tips from the Active Tip list from the Probe Utilities dialog box for which you would like to perform tip calibrations. The initial tip calibration only found offset information for the probe configuration.

9. Click Measure to begin tip calibration for all selected angles. If no angles are selected, you will be prompted to see if you want to calibrate all tips.

10. Select the appropriate sensor mode. The default is MODE3.

11. Select the Tips option from the Measure Laser Probe dialog box.

12. Verify that the same calibration tool that was used for tip calibration is selected.

13. Click Measure. PC-DMIS performs tip calibration and shows the Probe Utilities dialog box when it is finished.

14. For DCC CMS sensors, certain probe tip angles may result in the laser beam falling on a portion of the gauge stem. In some cases, the standard deviation for the probe calibration of those tips exceeds the expected amount. In those cases, PC-DMIS will display a message asking if you want to repeat the calibration of those tips. If you click Yes to repeat the calibration of the affected tip(s), the system uses the offsets and orientation determined by the first measurement instead of using the theoretical values. This results in a clipping around the target that is more accurate during this re-calibration.

Automatic Self-Centering of Tool Sphere During Calibration

Implementation of automatic self-centering of the tool sphere during calibration, when the sphere has been moved, is now available for the CMS laser sensor only.

This laser functionality applies when, during the sensor calibration, the sphere has been moved and PC-DMIS asks to bisect the calibration sphere.

When this happens, instead of PC-DMIS prompting the user to manually bisect the sphere, the user will have the additional functionality of displaying the calibration procedure in the live view and drive the laser sensor to the center of the sphere automatically.

The user will have two possibilities to operate at this point:

- Manually bisecting the sphere bringing it in the center of the Keystone and then press OK to start the laser calibration

- Display a portion of the calibration sphere in the live view and then press the Probe Enable button to automatically center the sphere. When completed, the user will press the OK button to complete the laser calibration.

CMS Auto-centering

The PC-DMIS Message dialog appears as soon as PC-DMIS determines that the calibration sphere has been moved.

Follow the instructions as described in the message box.

Press the OK button when done.

Note: For convenience, during the auto-centering procedure, the laser sensor alignment stripe will be displayed in yellow.

Note: When calibrating, PC-DMIS will override your current exposure and gray sum values with the default exposure and gray sum values detailed in the "Exposure and Gray Sum Settings During Calibration" topic. Once calibration finishes, the software will restore your original values.

Next Step ...

More:

Measure Laser Probe Options

Manually Bisecting the Calibration Sphere