拉脱法测量液体表面张力系数的电压测量点讨论与优化

Discussion and Optimization of Voltage Measuring Point for Measuring Liquid Surface Tension Coefficient by Pulled off Method

拉脱法测量液体表面张力系数实验中,力敏传感器对外输出电压是实验需要测量的重要参量。明确电压的测量点对于深入理解实验原理,提高实验测量精确度具有十分重要的意义。本文在传统拉脱法测量液体表面张力系数实验原理的基础上,重点对测量过程中吊环及液膜的状态、受力变化以及电压随吊环带出液膜高度的变化情况展开研究。最终明确了实验中电压测量点的选取,修正了理论分析计算公式并进行了实验验证。验证结果表明:吊环在临界状态时,传感器对外输出电压U_(1)应选取电压读数最大值更符合实验原理;且吊环带起液膜的质量不能忽略,应纳入理论分析计算中才能得到更为精确的结果。该研究结果可为本实验的课程教学提供分析思路与参考。

The output voltage of the force sensor is an important parameter to be measured in the experiment of measuring liquid surface tension coefficient by pulled off method.It is very important to understand the experimental principle and improve the accuracy of the experimental measurement.It focuses on the study of the state of the ring and the liquid film,the change of force and the change of voltage with the height of the liquid film carried out by the ring during the measurement process,based on the experimental principle of measuring liquid surface tension coefficient by traditional pulling method.Finally,the selection of voltage measurement point in the experiment is clarified,the theoretical analysis formula is modified and the experimental verification is carried out.The verification results show that when the sling is in the critical state,the sensor output voltage U_(1) should be selected as the maximum value of the voltage reading,which is more consistent with the experimental principle.Moreover,the quality of the liquid film can not be ignored and should be included in the theoretical analysis and calculation to get more accurate results.The research results can provide analysis ideas and reference for the course teaching of this experiment.