Method for measuring a first magnetic field and the temperature of a magneto-resistive transducer, the intensity of the first magnetic field being unknown, this method comprising: - the production, by the magneto-resistive transducer, of a measurement signal dependent on the intensity of the first magnetic field, this measurement signal also being dependent on the temperature of the magneto-resistive transducer, - the establishment of a measurement of the intensity of the first magnetic field on the basis of the measurement signal produced, and - the establishment of a measurement of the temperature of the magneto-resistive transducer, characterized in that the method also comprises: - the generation, at the same time as the first magnetic field, of a second magnetic field, on the basis of a generator electrically insulated from the magneto-resistive transducer, whose characteristics are known, this second magnetic field being combined with the first magnetic field to form a resultant magnetic field which is measured by the magneto-resistive transducer, - the extraction, from the measurement signal produced, of the component of this signal which is dependent solely on the second magnetic field alone, using the known characteristics of the second magnetic field, and - the establishment of the temperature of the magneto-resistive transducer on the basis of the component extracted. - the production, by the magneto-resistive transducer, of a measurement signal dependent on the intensity of the first magnetic field, this measurement signal also being dependent on the temperature of the magneto-resistive transducer, - the establishment of a measurement of the intensity of the first magnetic field on the basis of the measurement signal produced, and - the establishment of a measurement of the temperature of the magneto-resistive transducer, characterized in that the method also comprises: - the generation, at the same time as the first magnetic field, of a second magnetic field, on the basis of a generator electrically insulated from the magneto-resistive transducer, whose characteristics are known, this second magnetic field being combined with the first magnetic field to form a resultant magnetic field which is measured by the magneto-resistive transducer, - the extraction, from the measurement signal produced, of the component of this signal which is dependent solely on the second magnetic field alone, using the known characteristics of the second magnetic field, and - the establishment of the temperature of the magneto-resistive transducer on the basis of the component extracted. - the generation, at the same time as the first magnetic field, of a second magnetic field, on the basis of a generator electrically insulated from the magneto-resistive transducer, whose characteristics are known, this second magnetic field being combined with the first magnetic field to form a resultant magnetic field which is measured by the magneto-resistive transducer, - the extraction, from the measurement signal produced, of the component of this signal which is dependent solely on the second magnetic field alone, using the known characteristics of the second magnetic field, and - the establishment of the temperature of the magneto-resistive transducer on the basis of the component extracted.