质量时间法标准装置技术改进与初步性能测试

Technical improvement and preliminary performance test of mass-time primary standard device

关键词:  质量时间法  天然气  原级标准装置  中低压 

Key words:  mass-time method  natural gas  primary standard device  low-medium pressure

摘要:

目的 将质量时间法天然气流量原级标准装置的测量不确定度从0.05%~0.07%降至0.05%,以进一步提升量传溯源体系技术水平。方法 通过测量不确定度影响因素权重分析,提出电磁天平技术改进,滞止温度测量方式优化和环境温、湿度控制等措施,评定了该装置质量流量测量不确定度并开展初步性能评价。结果 电磁天平校准结果不确定度由1.0 g优化为0.5 g；滞止温度测量不确定度由0.034%优化为0.024%；环境温、湿度等引入的不确定度由0.02%优化为0.01%；测量审核结果小于1。结论 经技术改进后,质量时间法天然气流量原级标准装置质量流量测量不确定度全量程0.3~6.0 MPa实现0.05%(k=2)是可行的。 

Abstract:

Objective The aim is to decrease the measurement uncertainty from 0.05%-0.07% to 0.05% for low-medium pressure mass-time primary standard device, so as to further improve the technical level of traceability system. Methods Through the weight analysis of the factors affecting the measurement uncertainty, the measures such as the improvement of the electromagnetic balance technology, the optimization of the stagnation temperature measurement method and the control of the ambient temperature and humidity were proposed for the main measurement uncertainty. The measurement uncertainty of mass flow of the device was evaluated and the preliminary performance tests were carried out. Results The uncertainty of the calibration result of the electromagnetic balance was optimized from 1.0 g to 0.5 g; The measurement uncertainty of stagnation temperature was optimized from 0.034% to 0.024%; The uncertainty introduced by environmental temperature and humidity is optimized from 0.02% to 0.01%; The measurement audit result is less than 1. Conclusion sAfter technical transformation, it is feasible to achieve 0.05% (k=2) of the mass flow measurement uncertainty in the full range of 0.3-6.0 MPa of the low-medium pressure mass-time primary standard device.