一种真空状态下的气体流量测量新方法

当空气绝对压力小于40 kPa时,目前尚无简便有效的气流质量流量测量手段,为此本文设计了一套新颖的流量标定装置,并提出一种了流量测量方法。在流量调节过程中,调节阀必不可少。真空状态下,流经调节阀的流量几乎完全由阀前、后压力、气流温度四个变量决定。本文由流量标定装置获取有效的数据样本,基于多元非线性回归方法建立了流量与四者的关系表达式。一定范围内只要测定四个变量,则能直接计算出相应流量。实验结果表明计算值与实测流量偏差小于3.0%。

Novel Method for Gas Flow Rate Measurement in Vacuum

A novel technique has been successfully developed to precisely evaluate the gas flow rate,regulated by a control valve,in a base pressure below 40 kPa.The design considerations focused on the dependence of the flow rate on the four factors:the upstream and downstream pressures,temperature,and intake valve opening.An analytical expression between the gas flow rate and the four factors was derived by sampling the realistic data available with the calibrated gas flow meter,and by multi-element regression.After measuring the four factors in given ranges,the gas flow rate can be calculated.A prototyped meter of gas flow rate was designed,fabricated,and tested.The test results show that the relative error is less than 3.0%.