基于GMR磁传感器的油液铁磁性磨粒在线监测实验研究

Experimental Research on Oil Ferromagnetic Particles On-line Monitoring Based on GMR Magnetic Sensor

为实现对油液中铁磁性磨粒的在线监测,设计搭建一套在线监测装置;基于GMR磁传感器芯片可有效检测微弱磁场的特点,利用GMR磁传感器监测单个铁磨粒被磁化后的剩余磁场;采取"模拟在线"的形式,从GMR磁传感器输出的磁场信号中获取磨粒信息。通过优化装置和试验参数,研究温度、磨粒运动速度对测试系统输出结果的影响,探讨传感器的磨粒检出能力及检出结果的一致性。试验结果显示:在95℃以内的温度和5 cm/s以内的磨粒运动速度条件下,传感器的输出值基本不受影响;运动速度一定时,装置对不同粒度的磨粒输出一致性良好。试验初步表明了GMR磁传感器可用于油液铁磁性磨粒的在线监测,可有效检测出尺寸在75μm以上的铁磨粒。

An on line monitoring device was designed and accomplished to realize monitoring of ferromagnetic abrasive particles in oil in real time.Based on the characteristics of GMR magnetic sensor which can effectively detect weak magnet ic field,GMR magnetic sensor was used to monitor the residual magnetic field of a single iron abrasive after being magnet ized.The abrasive particle information was obtained from the magnetic field signal output by the GMR magnetic sensor in the form of “analog online”.By optimizing the device and experimental parameters,the influence of temperature and mov ing speed of particles on the output of test system was studied,and the detection ability of the sensor and the consistency of the detection results were discussed.The results show that under the condition of the temperature within 95 ℃and the mov ing speed of abrasive particles within 5 cm/ s,the output of the GMR magnetic sensor is almost unaffected by temperature and moving speed of abrasive particles.When the speed of magnetic abrasive particles is constant,the output of GMR mag netic sensor has good consistency for different sizes of magnetic abrasive particles.The experiment preliminarily shows that GMR magnetic sensor can be used for on line monitoring of ferromagnetic abrasive particles in oil,and can effectively detect ferromagnetic abrasive particles with sizes above 75 μm.