The CANtouch can be calibrated with firmware after 1.88.
This function was implemented after great demand. It boosts the accuracy of the showed absolute data.
All devices are calibrated from the factory (after serial number 22580 – 00/00102). A yearly calibration is suggested, even while it is not necessary for the measurement. Of course you can use the device also without yearly calibrations.
The calibration can only be done by the manufacturer.
You find the certificate of the last calibration in the menu at >Settings >Information > Calibration.