### Sample Calibration Target

##### Selecting and Using Calibration Targets

The following guidelines are intended to help you select a calibration target for measurements.

- Any dot grid type of target can be used for calibration.

- The calibration target should be chosen to fit the accuracy requirements of the application.

- In general, the calibration target should have a 5 to 10 times greater accuracy than the tolerance of the part to be measured.

- Chrome dots on a ceramic surface (or other diffuse surface) can be used for front-lit applications.

- Chrome dots on a glass surface can be used for back-lit applications.

- Calibration targets are available from many commercial suppliers. Two examples are shown below.

The example on the left is from Dot Vision: https://www.dot-vision.com.

The example on the right is from Edmund Optics: https://www.edmundoptics.com/f/diffuse-reflectance-grid-distortion-targets/13635.

- Target tolerances for commercially available grid calibration targets are typically +/-0.001mm (+/-1 micron), which is sufficient for most high-accuracy applications.

- Paper targets with lower accuracy can be printed from the Sysmac Studio Calibration Plate Print Tool and can be used to test the calibration process. The dots in the 15 x 15 grid are nominally 4 mm apart.

##### Calibration Guidelines

- It is very important that the dots on the calibration target be placed at exactly the same distance from the camera that the part will be. If the system is not calibrated with the target at the same distance, the measurements will read larger or smaller than the real-world dimensions of objects in the field of view.

- If it is not possible to set the dots of the calibration target at the same plane as the part, you can apply a scale factor determined by measuring a “golden part“ to adjust the readings.