What to consider when calibrating Lab Scanners

Scanner calibration is required for the calculation of the internal scanner geometry and camera parameters, to ensure good scan quality and accuracy. This article contains useful tips on what to keep in mind to calibrate the scanner correctly.

How often does the scanner need to be calibrated?

There is no set requirement on the frequency of calibration, however, the general recommendation is to calibrate the scanner once a week.

Situations/indications that re-calibration is required

• If the visual quality and/or accuracy of the scans is decreasing;
• If the current scanner temperature deviates from the temperature in the last calibration for +/- 5 °C, a warning that re-calibration is recommended will appear in ScanServer software.
• If the scanner has been transported or moved to another surface;
• If the last calibration was done more than 30 days ago (a warning that re-calibration is recommended will appear in ScanServer software).

What to keep in mind before calibrating the scanner and how to avoid the need for frequent re-calibration?

• Always use only the original calibration object that was supplied with the scanner - on the back side of the object there is a label with a serial number that corresponds to the serial number on the back of the scanner. Avoid using calibration objects from different scanners even though visually they are identical.
• Make sure the scanner is not calibrated cold. It is not recommended to calibrate the scanner "first thing in the morning" if it was turned off during night time - because during the day scanner's temperature will rise and a warning that re-calibration due to temperature deviation is required will pop up;
• Make sure that the temperature in the room is stable throughout the day and scanner is not placed next to the source of heat or at the window;
• Avoid touching the calibration object without a protective cover and always keep it on when the object is not in use, to make sure the calibration object is clean and not scratched (any scratches, dirt or dust can cause the calibration to fail or to be faulty leading to inaccurate scan results).
• If the calibration object was damaged, e.g. by dropping to the floor, do not try to fix it yourself - please contact support@3shape.com to order a replacement calibration object.
• Make sure to place the scan height adapter in the correct position. Please learn how to place calibration objects correctly for E-scanner and F8 in this article.