Measurement and shielding of extremely-low-frequency urban magnetic noise

摘要

Biomagnetic measurements are affected by environmental magnetic noises emitted by various electric systems including trains and elevators. In this study, we measured low-frequency magnetic noise by using a fluxgate magnetometer at a laboratory located in an urban area and analyzed the dominant noise sources during real-world operation of these systems. Additionally, we evaluated the noise reduction effect of a small, magnetically shielded box combined with compensation coils.