电涡流传感器多路测试系统的开发

Development of a Multi-Channel Test System for Eddy Current Sensors

摘要: 电涡流传感器是建立在电涡流效应上的新型传感器，能非接触地测量出被测金属导体表面与传感器探头之间的距离。广泛应用于电力、冶金、石油、化工和航空等行业以及一些科研单位，用来作为动力机械的监控装置或自动测试仪器。同时，电涡流传感器能很好地完成对水轮机、压缩机、齿轮箱和压缩泵等大型旋转机械轴的径向振动、轴向位移、偏心、胀差和转速等参数的测量，起到在线测量、在线监测、状态分析以及故障诊断的作用。电涡流传感器在长期使用时，可能因为老化或者受客观环境的影响，示值会出现很大的误差或者错误，所以需要通过定期的校准，发现并处理电涡流传感器存在的问题。校准时，用感应盘代替实际工况中的金属导体，并确保两者材料相同，进而保证电涡流传感器校准的准确性，一般校准周期为一年。现阶段大多数企业采用比较法校准电涡流传感器，通过正弦激励进行校准时，需要对多个频点逐步校准，校准过程相当费时。本文通过设计一套能够同时进行四个电涡流传感器的夹具设计和对电涡流传感器的电涡流的仿真以及配套多路测试软件的开发，完成了一套电涡流传感器多路测试系统，在保证校准精度的前提下，将电涡流传感器的校准效率提高了四倍。

Abstract: Eddy current sensors are a new type of sensor based on the eddy current effect, capable of non-contactly measuring the distance between the surface of the tested metal conductor and the sensor probe. They are widely used in industries such as power, metallurgy, petroleum, chemical, and aerospace, as well as in some research institutions, serving as monitoring devices or automatic testing instruments for power machinery. Simultaneously, eddy current sensors can effectively measure parameters such as radial vibration, axial displacement, eccentricity, expansion difference, and rotational speed of shafts in large rotating machinery such as turbines, compressors, gearboxes, and compression pumps, playing a role in online measurement, online monitoring, condition analysis, and fault diagnosis. During long-term use, eddy current sensors may exhibit significant errors or inaccuracies in their readings due to aging or environmental influences. Therefore, regular calibration is necessary to identify and address any problems with the eddy current sensors. During calibration, an induction disk is used instead of the metal conductor in the actual working condition, ensuring that both are made of the same material to guarantee the accuracy of the eddy current sensor calibration. The typical calibration cycle is one year. Currently, most companies use the comparative method to calibrate eddy current sensors. When calibrating with sinusoidal excitation, multiple frequency points need to be calibrated step by step, which is quite time-consuming. This paper presents a multi-channel testing system for eddy current sensors, designed with a fixture capable of simultaneously testing four eddy current sensors, simulated the eddy currents of the sensors, and developed supporting multi-channel testing software. This system improves the calibration efficiency of eddy current sensors by four times while maintaining calibration accuracy.