Construction and Experimental Verification of a New Miniature Low-Noise Hall Sensor for Wide-Range Vector Magnetic Field Measurements

The wide-range vector magnetic field measurements (up to the order of mT) have been employed for many years to measure currents, and displacements or detect magnetic anomalies in space applications. In recent years, solid-state-based magnetic sensors, such as Hall or magnetic-induction, have been extremely regarded for space missions because of their characterizations as miniaturized, highly sensitive, and robust. For this case, this article concerns the potential of using Hall sensors for wide-range vector magnetic field measurements. Specifically, we develop a new miniature Hall sensor with low noise and wide range to address the conflict between measurement range and noise. To estimate the capacity of the proposed Hall sensor, a dedicated trial platform is established and its specifications are comprehensively characterized, including resolution, noise floor, linearity, stability, and the capability of magnetic tracking. Furthermore, comparative magnetic anomaly detection is conducted using the proposed Hall and two commercial magnetic sensors. The results of the comparison experiments specify the ability of the developed low-noise Hall sensor for wide-range vector magnetic field measurements. The overall size is
$17\times 17\times3$
mm, the equivalent magnetic field noise density is
$0.0329 \mu \text{T}$
/Hz
$^{\text {1/2}}$
at 1 Hz, and the linearity error is 1% in the range from −4 to +4 mT, which can be employed for magnetic field observation with limited space. Compared to the commercial Hall sensor with the same noise level, the measurement range is increased by about 60% and the linearity is improved by about 500%.