To provide a calibration method of a magnetometer for a torque sensor.

This method of calibrating a magnetometer includes the step of causing a torque transducer to co-operate with a magnetometer including at least two channels for receiving a signal showing a magnetic field generated by the torque transducer in response to impressed torque, applying a necessary size of torque to the torque transducer at each of a plurality of prescribed calibration points, recording output signals indicative of a magnetic field generated at each of the prescribed calibration points communicated to each of the at least two channels, and determining a correction factor for each of the at least two channels, based on the recorded output signals for each of the prescribed calibration points.