基于分子流传感元件的真空腔体漏率测量方法

The Measuring Method of Leak Rate of A Vacuum Chamber Based on Molecular Flow Sensor Element

本文介绍了一种基于分子流传感元件的真空腔体漏率测量方法,该方法通过分子流传感元件测量真空腔体整体漏率,采用的测量装置由气体流量测量系统、真空抽气系统、恒温系统等部分组成。在测量系统中,流经传感元件的气流处于分子流状态,通过测量传感元件两端的差压,计算质量流量,可以得到真空腔体的整体漏率。实验中对多个真空腔体漏率的测量结果表明,该方法可以实现对10^(-5)-10^(-3) Pa·m^(3)/s量级真空腔体漏率的准确测量。除去本底漏率之后,测量结果与理论结果高度拟合,测量结果显示最小偏差为0.05%,最大仅为0.62%。且通过改变分子流传感元件流导值和差压变送器量程可以进一步扩展该方法可测真空腔体整体漏率范围。

This article introduces a method for measuring the leak rate of a vacuum chamber based on a molecular flow sensor element.This method measures the overall leak rate of a vacuum chamber through a molecular flow sensor element,the measuring device consists of a gas flow measurement system,a vacuum pumping system,and a constant temperature system.In the measurement system,the gas flow through the sensor element is in the molecular flow regime.By measuring the differential pressure across the sensor element and calculating the mass flow rate,the overall leak rate of the vacuum chamber can be obtained.The measurement results of the leak rate of multiple vacuum chambers in the experiment show that this method can achieve accurate measurement of the leak rate of 10^(-5)-10^(-3) Pa·m^(3)/s.After removing the background leak rate,the measurement results are well fitted with the theoretical results.The measurement results show that the minimum deviation is 0.05% and the maximum is only 0.62%.And by changing the molecular flow sensor element conductance value and differential pressure transmitter range can further expand the measurable range of the method.