A Weak Magnetic Measurement System with Large-Scale Uniformity and a Low Limit of Detection

This paper originally introduces a weak magnetic measurement system characterized by a large-scale uniform magnetic field and a low magnetic limit of detection (LOD). The system employs a four-ring coil assembly housed within a multi-layer magnetic shielding cavity, generating a uniform magnetic field region of 120 mm while achieving a minimum LOD of less than 10 pT. The performance of the weak magnetic measurement system is appropriately validated through the use of a bulk magnetic-electric (ME) sensor. The experimental results confirm the system's dual functionalities in both magnetic sensor calibration and the measurement of weak magnetic parameters. Notably, this methodology is readily applicable to various forms of weak magnetic measurement.