钟罩标准装置系统参数对被检智能流量计的影响

钟罩式气体流量计是用于检测智能型罗茨气体流量计计量误差是否符合国家计量要求的标准装置之一。通过对钟罩标准装置运行系统参数变化对检测结果误差影响的分析，纠正了采用传统的标定理论和方法标定智能型罗茨气体流量计过程中存在的附加误差问题。通过对检测原理的理论分析，找出了影响带温度和压力补偿的智能型罗茨气体流量计标定精度的主要因素--检测系统的管道压力损失。该压力损失导致检测系统的背景参数发生变化，在标定流量换算公式中考虑管道压力损失值的影响后，与试验测量结果的比较表明，最大可避免1％的检测不准确度，达到了消除由检测系统引起附加误差的目的。采用所给出的标准状态流量换算公式及系统参考压力值选择方法可提高钟罩标准装置的检测精度，确保智能型罗茨气体流量计标定结果的准确性。

ANALYSIS ON THE INFLUENCE OF THE SYSTEM PARAMETER OF ROOTS STANDARD FACILITY ON THE INTELLIGENCE FLOWMETER

Bell-jar type gas flowmeter is one type of standard facilities used to evaluate whether the metering error of Roots gas flowmeter conforms to the national measurement requirement or not. The additive error caused by the traditional calibration theory which was used to calibrate the intelligent Roots gas flowmeter were corrected via analyzing the influence of system parameter variation of Bell-jar standard facility on the measurement result error. Pipeline pressure loss, the main factors affected the calibration accuracy of intelligence Roots gas flowmeter with temperature and pressure compensation, were found out via a-nalysis on inspection theory. The pressure loss resulted in the background parameter variation of inspection system. When the influence caused by the pipeline pressure loss was taken into consideration in the calibration equation, up to 1% of the inspection inaccuracy can be avoided, which can eliminate the additive error. The inspection accuracy of the Bell-jar standard device can be boosted if adopted the flow rate calibration equation in standard condition and the pressure selection method. The accuracy of the Roots gas flowmeter can be assured.