A method for hydrating and calibrating an electrochemical sensor, comprising: - providing an electrochemical sensor, - providing a calibration solution to a measuring chamber of the electrochemical sensor, - contacting the electrochemical sensor with the calibrating solution within the measuring chamber, - exposing the electrochemical sensor and the calibration solution to an elevated temperature, comprising elevating at least the electrochemical sensor to a hydrating supporting temperature at which hydrating of the electrochemical sensor is facilitated, and characterized by - over a cooling period, - temperature controlled cooling of the electrochemical sensor and the calibration solution by means of a tempering device by which the temperature is continuously decreased and controllable within an device error range of temperature, - performing a plurality of calibrations of the electrochemical sensor, wherein a calibration of the plurality of calibrations is valid for a calibration margin of temperature error, the calibration margin of temperature error exceeding the device margin of temperature error, and - controlling the continuous decrease of the temperature of the electrochemical sensor and the calibration solution not to exceed the calibration margin of temperature error between consecutive calibrations of the electrochemical sensor. - providing an electrochemical sensor, - providing a calibration solution to a measuring chamber of the electrochemical sensor, - contacting the electrochemical sensor with the calibrating solution within the measuring chamber, - exposing the electrochemical sensor and the calibration solution to an elevated temperature, comprising elevating at least the electrochemical sensor to a hydrating supporting temperature at which hydrating of the electrochemical sensor is facilitated, and characterized by - over a cooling period, - temperature controlled cooling of the electrochemical sensor and the calibration solution by means of a tempering device by which the temperature is continuously decreased and controllable within an device error range of temperature, - performing a plurality of calibrations of the electrochemical sensor, wherein a calibration of the plurality of calibrations is valid for a calibration margin of temperature error, the calibration margin of temperature error exceeding the device margin of temperature error, and - controlling the continuous decrease of the temperature of the electrochemical sensor and the calibration solution not to exceed the calibration margin of temperature error between consecutive calibrations of the electrochemical sensor. - temperature controlled cooling of the electrochemical sensor and the calibration solution by means of a tempering device by which the temperature is continuously decreased and controllable within an device error range of temperature, - performing a plurality of calibrations of the electrochemical sensor, wherein a calibration of the plurality of calibrations is valid for a calibration margin of temperature error, the calibration margin of temperature error exceeding the device margin of temperature error, and - controlling the continuous decrease of the temperature of the electrochemical sensor and the calibration solution not to exceed the calibration margin of temperature error between consecutive calibrations of the electrochemical sensor.