气体流量计K系数的测量不确定度评定

EVALUATION OF MEASUREMENT UNCERTAINTY OF K COEFFICIENT OF GAS FLOWMETER

用音速喷嘴气体流量标准装置测量气体流量计,流量计的示值误差可以用累计流量示值误差和K系数示值误差表示,用K系数表示的流量计同步性好、数据处理方便快捷,在对计量精度要求不高的场合如企业内部交接计量和观察计量中经常使用。其测量不确定度主要由测量装置V m引入的不确定度和流量计输出脉N引入的不确定度构成,其中测量装置V m是测量不确定度关键影响量,在实际分析V m标准不确定度分量的过程中,由于测量设备、环境条件、测量方法和分析人员业务能力不同,评定出的测量不确定度也有所不同。文章以使用音速喷嘴气体流量标准装置测量涡轮流量计和罗茨流量计为例,全面对测量不确定度的影响量进行了分析,特别考虑了平时容易被忽视的空气湿度的影响,总结出评定气体流量计K系数的测量不确定度的完整方法和步骤。

A sonic nozzle gas flow standard device is used to measure the gas flow-meter.The value error of the flow-meter can be expressed by the value error of the cumulative flow and the value error of the K coefficient.The flow-meter expressed by K coefficient has good synchronicity,convenient and fast data processing,and is often used in the occasions where the accuracy of measurement is not high,such as the internal hand-off measurement and observation measurement in enterprises.Its uncertainty of measurement uncertainty and introduced by measuring devices Vm flow-meter output pulse N of uncertainty,the introduction of the measuring device Vm is a key influence quantity of uncertainty of measurement in the actual analysis of Vm standard uncertainty components in the process,because the measuring equipment,environmental conditions,measurement method and analyzed by different business ability,evaluation of measurement uncertainty is also different.Based on sonic nozzle gas flow standard device is used to measure the turbine flow-meter and roots flow-meter,for example,a comprehensive impact on measurement uncertainty quantity is analyzed,especially considering the easily neglected the effect of air humidity at ordinary times,summarizes the evaluation of gas flow-meter coefficient K of uncertainty of measurement methods and steps of the complete.