偏置磁场对磁致伸缩液位传感器检测电压的影响

摘要

To improve the detection accuracy of a magnetostrictive liquid level sensor , different placements of float magnets in the bias magnetic fields of the sensor and its impact on the detection voltage were researched .The bias magnetic fields generated by float magnets in different placements were analyzed by the finite element analysis of ANSYS software .It was found that when three pieces of magnets under NNS placement or one single ring magnet are chosen as bias magnetic field ,the detection voltage waveform is in line with expectations .Besides ,the effects of bias magnetic field of magnetostrictive liquid level sensor were done on detection voltage were experimentally studied and the experiments were done more times for the float magnets at different placements .The experiment results verify that when the bias magnetic field is generated by three pieces of magnets under NNS placement or one single ring magnet ,the amplitude of detection voltage reaches 50 mV ,which has improved almost 30 mV as compared with that of other ways .It suggests that three pieces of magnets under NNS placement or one single ring magnet can be applied as the bias magnetic field of magnetostrictive liquid level sensors .%为了提高磁致伸缩液位传感器的检测精度，研究了磁致伸缩液位传感器中产生偏置磁场的浮子磁铁的放置方式及其对检测电压的影响。利用 ANSYS 软件对浮子磁铁不同放置方式下形成的偏置磁场进行了有限元分析，分析显示：采用3块磁铁互成120°N 极 N 极 S 极（NNS）放置或者采用圆环磁铁作为偏置磁场时检测效果比较理想。实验研究了磁致伸缩液位传感器的偏置磁场对检测电压的影响，并在浮子磁铁不同放置方式下进行多次实验。结果表明：偏置磁铁为3块磁铁互成120°NNS 放置时或者为圆环磁铁时，检测电压的幅值达到50 mV ，比其它放置方式提高了近30 mV 。研究表明：磁致伸缩液位传感器应选择3块磁铁 NNS 放置或者选择圆环磁铁作为偏置磁场。