Micro-magnetic Field Measurement using Hall Element

Magnetic sensor characteristics of InSb Hall element with a ferrite sandwich structure were investigated. This sensor can accurately measure a magnetic field of the order of 1 µT and the standard deviation of the measured magnetic field is about 130 nT. Fluctuation of the offset voltage and noise power spectrum was measured and 1/f noise was observed up to 10 kHz for applied current of 8 mA. It was also found that the noise power spectrum density was proportional to input current.