不同读数方法测量金属线膨胀系数的比较

Comparison about Different Reading Methods in Measuring Linear Expansion Coefficients of Metal

利用FD-LEA型金属线膨胀系数测定仪与GXZ-2金属线膨胀系数仪测量铜、铁、铝的线膨胀系数,分别采用升温过程中达到某一温度时的长度变化量瞬时读数和待长度变化量稳定后读数两种读数方法记录瞬时值和稳定值。实验结果分析发现:在使用FD-LEA型线膨胀系数测定仪时应采用待长度变化量稳定后读数的方法;在使用GXZ-2金属线膨胀系数仪时应采用升温过程中达到某一温度时的长度变化量瞬时读数的方法。实验时采用FD-LEA型金属线膨胀系数仪在长度变化量稳定后读数所得结果相比其他仪器其他方法的结果更为准确,因此在实验教学中可优先选择FD-LEA型线膨胀系数测定仪。

FD-1,EA-type and GXZ-2-type linear expansion coefficient instruments are common instruments used in university physics experiment teaching. In order to compare different methods, the linear expansion coefficient of copper, iron and aluminum were measured by FD-LEA-type and GXZ-2-type linear expansion coefficient instruments. The instantaneous values and the stable values were recorded by using the length change instantaneous reading when the temperature reached a certain value, and the length change stable reading two methods, respectively. It was found that the length ehange stable reading method should be adopted when using FD-LEA-type linear expansion coefficient instrument, the length change instantaneous reading method should be adopted when using GXZ-2-type linear expansion coefficient instrument. The measurement result was the most aceurate when using FD-LEA-type linear expansion coefficient instrument, so the FD-LEA-type linear expansion eoeffieient instrument could be selected in experimental teaching.