测量空气相对压力系数的系统误差分析

Analyzing systematic errors of the experiment to measure the coefficient of air relative pressure

差压传感器测空气相对压力系数是中国地质大学（北京）大学物理实验中唯一1个热学实验。由于实验装置和所研究体系本身存在系统误差,导致实验测得结果与理论值产生了一定的偏差。经实验测得,误差主要来自差压传感器的输入电压、差压传感器的非线性特征、真空泵抽取的真空度、气体温度不均匀程度、空气的水蒸气含量等5个方面。经综合分析后,推导出测量装置的系统误差补偿公式,可对实验教学中直接测得的空气相对压力系数进行修正,以便得到更接近于真实值的结果,实现验证性实验的教学意义。

Using pressure sensor to measure the coefficient of air relative pressure is the only calorifics experiment in the college physics experiment.The experimental device brings some systematic errors leading the bias between the final experimental result and the theoretical value.The five systematic errors are from the input voltage,the non-linear phenomenon of pressure sensor,vacuum pump,the change of the bulb＇s volume,the humidity and non-uniform temperature of the air.This paper analyzies the five influencing factors to the final experimental results,and gives the correction of the coefficient.