What is an uncalibrated magnetic sensor?
Similar to magnetometer but the hard iron calibration (device calibration due to distortions that arise from magnetized iron, steel or permanent magnets on the device) is not considered in the given sensor values.
Also, no periodic calibration is performed (i.e. there are no discontinuities in the data stream while using this sensor) and assumptions that the magnetic field is due to the Earth's poles is avoided, but factory calibration and temperature compensation have been performed.