声磁传感器及其频谱检测技术研究

Research of acoustomagnetic sensor and its frequency spectrum detection technology

声磁传感器基于材料的磁致伸缩效应,当对其施加交变磁场激励信号,并且交变激振信号的频率与材料的固有频率相等时,材料将产生磁力共振。接收装置检测到材料由于共振而产生的声波信号,并经过处理得到声磁传感器的共振频率及响应幅值。由此,可以研制应用于物品识别、电子防盗等领域各种不同功能的声磁传感器。其基本结构组成包括偏磁元件、振动元件及壳体等。影响该类传感器灵敏度与精度的主要因素有振动元件的结构参数、偏磁元件的剩磁场,以及振动元件材料的物理性质等。

Based on magnetostrictive mechanism of magnetic materials, acoustomagnetic sensor will present magnetomechanic resonate phenomenon, when it is put on alternating magnetic field, and the frequency of the alternating magnetic field is same to inherent frequency of sensor. The sound wave signal emitted by sensor because of magnetomechanic resonance is detected by receiving equipments, and the resonance frequency and corresponding swing peak value can be picked up after proper disposal. So, various different sensor can be developed to use such as for article identified, electronic surveillance, etc. The sensor is made u Pof bias unit, vibrating unit and carapace. The factors affecting sensitivity and precision of sensor are mainly consist of structure parameters, physical characters of vibrating unit, remanence of bias unit, etc.