Calibration & temperature comensation SDP33

Dear friends,
My name is Jakub Koślacz and I bought one of your pitot tube with SPD33 sensor. There is in description that it is calibrated and has a temperature compensation. But what shall I do when after few months it seems to show too high airspeedrs? I use Pixhawk 2.1 Cube with ArduPlane. Can you explain me how the temperature compensation works? And if it is implemented, should I do calibration in software (autocalibration of airspeed ratio), and what determines when it should be calibrated?
Jakub Koślacz