容积率对气体比重瓶法测碳纤维密度的影响探究

Research on the Influences of Volume Ratio on the Measurement of Carbon Fiber Density by Gas Pycnometer Method

基于气体比重瓶法测碳纤维密度的原理和过程,采用模拟和试验来探究样品仓中碳纤维的容积率对密度测定值的影响并分析其成因。结果表明:随着容积率的增大,压力传感器两次测量的差值ΔP也越大,碳纤维密度的相对不确定度越小,在表观容积率大于60%以后,碳纤维密度测定值趋于稳定。从而得到了气体比重瓶法测量碳纤维密度需保证试样表观容积率≥60%的结论。

Based on the principle and process of measuring the density of carbon fiber by gas pycnometer method,simulation and tests were made to explore the influences of the volume ratio of carbon fiber in the specimen chamber on the measured density and then analyze their causes.The results showed that with the increase of the volume ratio,the differenceΔP between the two measurements by the pressure sensor was larger and larger,and the relative uncertainty of the carbon fiber density was smaller and smaller.After the apparent volume ratio became greater than 60%,the measured value of carbon fiber density tended to be stable.Therefore,it is concluded that the measurement of carbon fiber density by gas pycnometer method needs to ensure that the apparent volume ratio of the specimen is≥60%.