Calibrate Illumination

This calibration procedure allows you to calibrate the lamps for your machine. Lamp calibration ensures that the illumination range is linear, and that changing magnification (Pixel Size) on zoom cells will not significantly change the illumination on the part within the capability of the hardware.

You should calibrate your optical system's lighting at these times:

• Whenever you change or replace a lamp, you should recalibrate that lamp.

• Whenever you have a significant change to the lighting within the room.

• Periodically throughout the life of the lamp.

• When you change the brightness or gain setting on the camera.

• When the optics are replaced.

• When the zoom cell is repaired.

• When the camera is replaced.

• Prior to calibrating Parcentrality/Parfocality when you "Calibrate Optics" since this is required for this calibration.

To calibrate lamps, follow these steps:

1. On the Calibrate Probe dialog box, from the drop-down list, select Calibrate Illumination.

2. Click Calibrate to show the Calibrate Illumination dialog box with the calibration date for each lamp in parenthesis. If you haven't calibrated a lamp the text in parenthesis says "Uncalibrated".

   

   Calibrate Illumination dialog box

3. Select the check box next to the lamp that needs to be calibrated.

4. Prepare for calibration as directed according to the lamp type:

   • Sub-stage (bottom/profile) lamps require the stage to be cleared during calibration, with the image focused on the stage.

   • Top (surface/ring) lamps require an artifact or piece of paper to be in the Field of View, with the image focused on the surface.

5. Mark the Adaptive Mode check box to apply the adaptive calibration mode to the calibration process if required.



Calibrate Illumination dialog box with Adaptive Mode check box marked

The Adaptive Calibration mode may cause issues with existing measurement routines. Without the Adaptive Calibration mode, the levels across some hardware configurations were inconsistent. The actual illumination seen in the camera did not match the commanded value. After the Adaptive Calibration mode illumination calibration, the machine illumination seen in the camera will match the commanded value.

6. Click Calibrate. The calibration process begins. The process takes several minutes.

• During calibration on systems with a zoom cell, PC-DMIS Vision selects different magnifications for illumination measurement as indicated by the Magnification Step value. This value displays the current magnification and corresponds to the value displayed in the Magnification tab of the Probe Toolbox.

• The calibration also sets the illumination intensity corresponding to the different commanded illumination values at different magnifications. The Lighting Grayscale indicates the intensity of this illumination. The values range from 0 (black) to 100 (white).



Calibration Illumination - in progress

• Once the calibration finishes, the Calibrate Illumination dialog box displays the new date for the calibrated lamp.

7. After PC-DMIS completes the calibration process, click the Close button or repeat steps 3 through 6 to calibrate another lamp.

The Abort button is only available during a calibration. This button stops the calibration, aborts any data collected during the process, and reinstates any pre-existing calibration files for the current lamp.