一种基于CF400接口分子泵抽速测试装置

针对国产化大抽速分子泵测试需求,研制出基于CF400接口分子泵抽速测试装置。采用量程为10~10^-9 Pam³/s的复合型标准气体流量计提供可变的标准流量,仅用流量法实现了测试罩内气体压力处于10^-1~10^-7 Pa范围的抽速测试,而传统测试方法采用标准流导法和流量法相结合实现该范围的测试;装置集成了在线真空校准功能,用磁悬浮转子真空计作为参考标准,实现在10^-1~10^-4 Pa范围内对测试罩内气体压力的直接测量及副参考标准电离真空计的在线校准。研制的装置与原有测试方法相比较优点主要为:采用一种方法实现了分子泵抽速测试;在线校准技术解决了原有测量过程电离真空计灵敏度系数发生变化引起测量结果出现的较大偏差;实现对不同气体抽速的直接测量,避免原方法只能给出等效氮气测试结果的不足。实验结果证明,装置对分子泵抽速的测试范围为3000~5000 L/s,测量结果的合成标准不确定度为2.2%~4.4%。

Lab-Built Test-Platform for Pumping-Speed Measurement and Calibration of CF400 Molecular Pump

The test platform was developed for on-line measurement and/or calibration of pumping-speed of molecular pump with an interface diameter of 400 mm.The lab-built test platform comprised the measurement dome module,compound standard flow-meter module,with full-scale range of 10~10^-9 Pam³/s,measurement and calibration module,with a magnetic suspension rotor vacuum gauge(SRG) as the reference,capable of evaluating pressure in 10^-1~10^-7 Pa range,and it measures and/or calibrates on-line the pumping-speed only in the throughput method.Test results show that the lab-built test platform is capable of precisely measuring a pumping-speed in 3000~5000 L/s range,with a combined standard uncertainty of 2.2%~4.4%.The lab-built test platform outperforms the conventional one for three reasons,including the one measurement method,significant smaller discrepancy for on-line measurement/calibration of pumping-speed,and direct measurement of the gases other than nitrogen.