差压传感器的非线性对空气相对压力系数的影响研究

差压传感器测空气相对压力系数是大学物理实验中唯一一个热学实验。通过对空气相对压力系数的验证,可以让学生加深对气体状态方程的理解,同时学习差压传感器的工作原理及测量方法。抽取真空时,传感器会出现满量程或超出量程的情况,使显示出的电压值与实际气压值之间的关系呈现非线性,导致换算出的气压值与真实值存在偏差,从而给测定出的空气相对压力系数带来误差。通过大量实验,测定了非线性给实验带来的系统误差,同时推导出补偿公式,对测得的空气相对压力系数进行了修正。

Study on effect of the nonlinear phenomenon of pressure sensor to the measurement of the coefficient of air relative pressure

Experiment of using pressure sensor to measure the coefficient of air relative pressure is the only calorifics experiment in the college physics experiment.Students can have a deepen understanding on the gas equation and learn the theory and utilization of pressure sensor.When extracting vacuum,the sensor has the situation in or over the range which causes the nonlinear phenomenon between the shown voltage and the actural pressure.It also brings the deviation of calculated pressure with the actural pressure so that the errors are brought into the measurement of the coefficient of air relative pressure.In this paper,the systematic errors because of nonlinear phenomenon are measured by carrying out many experiments and the compensation formula is induced to revise the measured coefficient of air relative pressure.