提高霍尔器件检测灵敏度的一种方法

IMPROVEMENT OF THE SENSITIVITY OF HALL PROBE

霍尔器件是漏磁检测中最常用的磁传感器,周期方波电流用作激励源可提高其灵敏度。试验表明,对于同样的外磁场,与直流激励相比,一定幅度的周期方波电流可使霍尔输出提高20dB。介绍方法的基本原理和信号处理方法,给出了方波电流幅度和霍尔输出的关系曲线,并从理论上进行了解释。考察了采用周期方波电流后霍尔输出和外部磁场之间的线性关系的变化,最后比较了同样条件下,用直流激励和方波激励时0.1mm深裂纹的检测结果。

Hall probe is the most commonly used sensor in magnetic flux leakage testing. Periodical square-wave current is used as the exciting source in order to increase the Hall probe sensitivity. For the same magnetic field strength, the output of Hall probe will increase 20dB comparing with the direct current. The principle of the method and the signal processing are introduced. The relationship of Hall probe output and the square-wave current amplitude is found and the theoretical explanation is also given. The change of Hall probe output linear is concerned too. At last, the testing results of 0. 1mm deep surface crack with direct current and square-wave current are compared.