重液密度计校准方法及不确定度评定  

Calibration method and uncertainty evaluation of heavy density hydrometer

作　　者：陈超云[1] 张怡雯 文慧卿 金愿 Chen Chaoyun;Zhang Yiwen;Wen Huiqing;Jin Yuan(Shanghai Institute of Measurement and Testing Technology;Suzhou Institute of Metrology)

机构地区：[1]上海市计量测试技术研究院 [2]苏州市计量测试院

出　　处：《上海计量测试》2024年第5期38-40,共3页Shanghai Measurement and Testing

基　　金：项目“基于固体密度标准的玻璃浮计检定装置的研制”(E00RY2407)的支持

摘　　要：针对重液密度计的相关技术规范尚未制定,校准方法仍然存在不足,采用静力称量法搭建重液密度计校准装置,以十三烷作为重液密度计校准介质,通过GBW13985液体密度标准物质校准振动式液体密度仪,再用振动式液体密度仪进行标定。对密度范围为2000~2100 kg/m^(3),分度值1 kg/m3的重液密度计校准试验,重液密度计三个校准点处的修正值均小于1.0 kg/m^(3),满足最大允差的要求。考虑液体表面张力、空气密度、玻璃体膨胀系数等因素的影响,对测量结果的不确定度进行评定,得到扩展不确定度U=0.3 kg/m^(3),k=2。试验结果表明该方法能够拓展玻璃浮计测量范围,为重液密度计的校准提供有效的技术路径。In view of the fact that the relevant technical specifications of the heavy density hydrometer have not been formulated and the calibration method is still insufficient,a calibration device for the heavy density hydrometer is built by using the hydrostatic weighing method.Using tridecane as the calibration medium for the heavy liquid density meter,the vibrating liquid density meter is calibrated using the GBW13985 liquid density standard,and the density of the medium is measured using the vibrating liquid density meter.For the calibration test of the heavy density hydrometer with density range of 2000-2100 kg/m^(3) and division value of 1 kg/m^(3),the correction values at the three calibration points of the heavy density hydrometer are all less than 1.0 kg/m^(3).Considering the influence of liquid surface tension,air density,vitreous expansion coefficient and other factors,the uncertainty of the measurement results is evaluated,and the extended uncertainty U=0.3 kg/m^(3),k=2.The test results show that this method can expand the measuring range of hydrometer and provide an effective technical path for the calibration of heavy density hydrometer.

关 键 词：重液密度计 静力称量法 密度测量 不确定度 

分 类 号：TH715.2[机械工程—测试计量技术及仪器]