本文基于光泵磁共振频幅响应设计和制作微弱磁场测量仪,采用扫频法进行微弱磁场的测量,简单直观且测量频谱宽,用锁相放大器实现扫频,设置扫频区间驱动线圈激励扫频磁场,并结合DSP28335开发板的AD模块实现信号锁相放大与采集分析,利用DSP28335和硬件器件相配合设计的PID温控系统,合理设计装置结构.对实验结果进行分析,相对测量误差小,装置方便操作易调节,该系统可稳定测量μT量级微弱磁场,能够基本满足大学物理进行微弱磁场测量实验的教学要求.

This paper presents the design and fabrication of a weak magnetic field measurement instrument based on optical pumping magnetic resonance frequency-amplitude response. The instrument employs a sweep frequency method for measuring weak magnetic fields, offering a simple and intuitive approach with a wide measurement spectrum. A phase-locked amplifier is used to implement the sweep frequency, with the sweep frequency interval set to drive the coil and generate the sweep magnetic field. The AD module of the DSP28335 development board is utilized to achieve signal phase-locked amplification and data acquisition/analysis. A PID temperature control system was designed using the DSP28335 and hardware components, with a reasonable structural design for the apparatus. Analysis of the experimental results showed a small relative measurement error, and the apparatus is easy to operate and adjust. This system can stably measure weak magnetic fields at the μT level, and can basically meet the teaching requirements for weak magnetic field measurement experiments in university physics courses.