摘要
形状复杂或非匀质刚体的转动惯量可以利用三线摆测量,其中,扭摆周期是关系到测试精度的重要参数.人工计数和秒表计时费心费力,容易出错.采用光电传感器和单片机测量容易受到横摆或晃动的影响,导致漏记一个周期.为此,提出一种新型三线摆周期测量装置,由光源、起偏器、检偏器、光敏电阻模块、数据采集系统和安装有上位机软件的电脑构成,利用光的偏振特性和马吕斯定律来检测三线摆下盘的扭摆情况.利用Origin软件的线性拟合功能处理数据可以得到三线摆扭摆的周期.利用市场上现有的光电测量装置和新型三线摆周期测量装置同时进行对比实验,测量三线摆下盘的转动惯量.实验结果表明:利用现有的光电测量装置,相对误差为0.83%;利用新型三线摆周期测量装置,相对误差可达0.11%,系列实验结果说明新型三线摆周期测量装置的准确度比现有的光电测量装置要高.因为三线摆下盘的横摆或晃动引起的起偏器小范围的平动并不影响透射光的强度,所以,新型三线摆周期测量装置的抗干扰能力较强.此外,该装置还具有测量速度快、操作简单、方便、快捷等优点,具有一定的推广价值.
The rotational inertia of complex or heterogeneous rigid body can be measured by trifilar torsional pendulum.The torsion pendulum period is an important parameter related to the accuracy of the test.Manual counting and stopwatch timing are very laborious and easy to make mistakes.The photoelectric sensor and the measurement are easily affected by the yawing or shaking,which will lead to the omission of one period.To this end,a new type of trifilar torsional pendulum periodic measuring instrument is proposed,which consists of light source,polarizer,detector,photosensitive resistance module,data acquisition system and computer installed with upper computer software.The polarization characteristics of light and Marius's law are used to detect the torsion pendulum situation of the trifilar torsional pendulum.We can get the period of trifilar torsional pendulum by using the linear fitting function of origin data processing software.Using the photoelectric measurement device in the market and the new trifilar torsional pendulum period measuring instrument at the same time,a comparative experiment is carried out to measure the moment of inertia of the lower plate of trifilar torsional pendulum.The experimental results show that the relative error of the existing photoelectric measuring device is 0.83%,and the relative error of the new trifilar torsional pendulum period measuring instrument is up to 0.11%,indicating that the accuracy of the new type trifilar torsional pendulum periodic measuring instrument is higher than the existing photoelectric measuring device.Because the intensity of the transmission light is not affected by the small range swing or sloshing of the trifilar torsional pendulum,the new rifilar torsional pendulum periodic measuring instrument has a strong anti-interference ability.Besides,the device has the advantages of fast measuring speed,simple operation,convenience,and has certain popularization value.
作者
石明吉
李波波
王飞
SHI Ming-ji;LI Bo-bo;WANG Fei(School of Electronic and Electrical Engineering,Nanyang Institute of Technology,Nanyang 473004,China)
出处
《大学物理》
2019年第5期30-34,共5页
College Physics
基金
南阳理工学院省示范校建设专项研究项目(SFX201718)
南阳理工学院高等教育研究基金项目(2017-NGGJJJ-002)资助
关键词
转动惯量
三线摆
偏振
光敏电阻
横摆
rotational inertia
trifilar torsional pendulum
polarization
photosensitive resistance
yaw
