对静态拉伸法测杨氏模量实验的改进及误差分析

摘要

By the principles of static stretching and optical zoom, the paper improved the method which is increasing （decreasing） weights to measure small elongation of the steel wire gradually by adding or subtracting weights for just only one time and reading the ruler scale value repeatedly. And also determines the optimal distance between the mirror and the telescope within visual distance by the control of the distance between the ruler and the mirror, under the circumstance of guarantee- ing quality of small elongation measurement quality of slight elongation. According to the experiment principle and its uncertainty analysis combine with measurement data the paper works out young＇s modulus of steel wire. And the paper achieves more reasonable results by the analysis and evaluation with confidence probability of 95%.%由静态拉伸法结合光放大原理，用一次性增（减）砝码反复读取标尺刻度值的测量方案，对逐步增（减）砝码来测量钢丝微小伸长量的测量方法进行改进，通过对镜与标尺距离的控制，在保证微小伸长量测量质量的前提下，确定望远镜可视距离内的最佳镜与尺距离。由实验原理及其不确定度的分析，结合测量数据，计算出钢丝的杨氏模量。用置信概率为95％的不确定度对实验数据进行分析与评定，得到了较为合理的实验结果。