交流电桥测量金属线膨胀系数  

Measuring linear expansion coefficient of metal by using alternating current bridge

作　　者：李儒颂 徐芹[1] 魏怀鹏[1] 

机构地区：[1]河北工业大学理学院,天津300401

出　　处：《实验技术与管理》2015年第12期69-72,共4页Experimental Technology and Management

基　　金：河北省青年基金项目(A2015202343);河北省高校重点学科项目;大学生创新创业训练计划(201413584001)资助课题;河北省高等学校科学技术研究项目(QN2015260)

摘　　要：利用交流电桥精确测量金属棒线膨胀系数。将待测电感做成一个长螺线管,利用恒温加热装置使金属棒均匀受热膨胀,推动与其紧密接触相连的磁性圆棒在长螺线管内移动,导致螺线管本身电感量的变化,最终实现金属棒膨胀变化量与交流电桥电感变化量的转换。为减小加热装置的温度梯度,控温系统是在传统的蒸气喷射加热仪的基础上,组合黏滞系数实验部分仪器和温度传感器而成。实验测试结果与理论计算吻合很好。实验表明,此测量方法不仅具有操作简单和测量精度高的优点,而且此种非电量电测法可实现智能化测量,还可以用于其他物理量的测量,具有一定的实用价值。A simple method of precisely measuring linear expansion coefficient of a metal bar is reported.It can be realized by manufacturing inductance components using measuring small inductance of alternating current bridge principle.The thermostatic device can be used to get the metal bar expanded of which the top can push the solenoid forward,this movement can make the inductance value change,resulting the transformation of the expansion variation and the inductance variation.Besides,in order to reduce the temperature gradient of the thermostatic device,the temperature-control system was achieved by means of combining the viscosity coefficient device and the temperature sensor based on the steam spray heat device.The feasibility of the theory is demonstrated,and the experimental result is in good agreement with the theoretical calculation.It shows that the method is easy to operate and control accurately,and this experiment doesn＇t need electricity,so it can realize intellectualized measurement with a good prospect and value in use.

关 键 词：线膨胀系数 交流电桥 磁性圆棒 长螺线管 控温系统 

分 类 号：O4-34[理学—物理]