Abstract Leakage flow rate is one of the most important contributions to the measurement uncertainty when measuring small gas flow rates with a clearance-sealed piston prover. Our previous study has shown that the systematic effects related to the change of the gas viscosity can be successfully corrected, whereas the effects related to the reproducibility of the leakage flow rate are poorly understood. This paper focuses on the interpretation and correction of the reproducibility related effects by analysing experimentally identified variations of the leakage flow rate and the gas pressure in the inclined piston prover. Small changes of the leakage flow in the inclined piston prover indicate that the position of the piston relative to the cylinder remains approximately the same. The obtained relationship between the leakage flow rate and the gas pressure below the piston led to the pressure-based correction of the leakage flow rate.

中文翻译：

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间隙密封活塞检验仪中泄漏流量与压力变化的相关性

摘要 在使用间隙密封活塞校准器测量小气体流量时，泄漏流量是造成测量不确定度的最重要因素之一。我们之前的研究表明，与气体粘度变化相关的系统影响可以成功纠正，而与泄漏流量再现性相关的影响却知之甚少。本文通过分析实验确定的泄漏流量和倾斜活塞校准器中气体压力的变化，重点解释和修正与再现性相关的影响。倾斜活塞校准器中泄漏流量的微小变化表明活塞相对于气缸的位置保持大致相同。