基于电容位移传感器的金属线胀系数测量

摘要

针对由微小位移测量误差引起金属线胀系数测定实验精度降低的问题,介绍了一种传感器测量金属线胀系数的新方法.变极距式电容位移传感器在有效的线性工作范围内输出电压与极板间隙的变化具有良好的线性输出关系,能极大地提高金属受热膨胀时微小位移的测量精度.利用变极距式电容位移传感器替代千分表测量金属线胀系数,不仅操作简单,实验测量误差大幅降低,而且能实现数据采集和处理的一体化.%This paper presents a new method for measuring the metal linear expansion coefficients in order to improve the accuracy of experiment. Under the linear area of output, there exists a good linear relationship between the output voltage and the change of plate distance. The micro-distance measurement is measured by means of capacitance displacement transducer with variable distance between electrodes in the experiment of linear expansion coefficient measurement. The novel method proposed in this paper not only greatly improves the accuracy of the experiment, but also helps to cultivate the ability of comprehensive application of knowledge, and let students feel the charm of modern physical technology.