磁芯感应线圈传感器综述

A review on ferromagnetic induction coil sensors

回顾了地球物理领域应用广泛的磁芯感应线圈传感器.详细介绍了它的工作原理;给出了详细的设计公式和步骤;分析了三种形式的磁芯损耗,表明了材料是影响传感器性能的主要因素之一,比较了铁氧体、坡莫合金和无定形材料三种材料的不同特点;分析了传感器频率特性及频率补偿电路对频率特性的改善;介绍了两种不同的输出信号处理方法;指出了磁芯线圈传感器的设计难点在于磁芯的制造工艺和绕线方法;标定是传感器研制的一个关键步骤,标定对环境要求极高,需要在磁屏蔽室内进行,介绍了中国地震局地球物理研究所的大型磁屏蔽室结构;地磁场的补偿是标定系统的一个难点,一般采用一个单独的参考磁力仪对地磁场进行补偿.

The ferromagnetic induction coil sensors are reviewed. They gain broad applications in the geophysic domain. The principle and detailed formulas and procedure are presented. The magnetic core losses can be split into three components. The core material is one of the major factors affecting the sensors performance. The characters of ferrite, mu-metal and amorphous core material are compared. The frequency characteristic of the sensors is analyzed and improved by employing the frequency compensation circuit. Two methods of output signal processing are presented. The difficulties in designing the sensor are the manufacture arts and wire winding method. The calibration is a key process in designing of the sensor. The requirement for environment is rigorous and should be carried out in a magnetic shielding room. The structure of the magnetic shielding room of Institute of Geophysics, China Earthquake Administration is specially described. The compensation of the earth＇s magnetic field is one difficulty in the calibration system and the method to cancel the influence with an independent reference magnetometer is described.