真空计量标准的研制与应用

R&D of vacuum metrologic standards in LIP and their applications

兰州物理研究所研制了一系列真空标准装置,可用于真空规、方向规、分压力质谱计、真空漏孔和正压漏孔的校准。其静态膨胀法真空标准装置、动态流量法真空标准装置及超高/极高真空校准装置是用于真空规校准的三套基础标准,覆盖的校准范围为(10-10～105)Pa;程控式真空规校准装置适用于工业部门,其校准范围为(10-4～105)Pa;为实现质谱计的校准,研制了一台具有三路相同独立进样系统的分压力质谱计校准装置,标准分压力通过磁悬浮转子规以两种不同的方法进行测量,该校准装置可实现(10-7～10-1)Pa范围内的分压力校准;为实现真空漏孔的校准,研制了恒压式气体微流量标准装置和固定流导法气体微流量标准装置,恒压式气体微流量标准装置的校准范围为(10-8～10-2)Pa·m3/s,固定流导法气体微流量标准装置的校准范围为(10-10～10-5)Pa·m3/s,漏孔漏率的校准通过比较被校漏孔和标准气体微流量计在一台四极质谱计上引起示漏气体离子流的大小计算得到;为实现正压漏孔的校准,研制了一台正压漏孔校准装置,采用定容法和定量气体动态比较法对正压漏孔进行校准,校准范围为(5×10-8～10-1)Pa·m3/s;研制了一台定向流真空校准装置,实现对方向规的校准和非平衡态分子流的研究,装置的校准范围为(10-7～10-1)Pa。

A series of vacuum standards was developed by LIP （Lanzhou Institute of Physics） to calibrate vacuum gauges, directional gauges,mass spectrometers for partial pressure, vacuum leaks and pressure leaks. To calibrate vacuum gauges, three kinds of primary vacuum standards over the calibration range from 10-l^Pa to 10SPa were developed, including the static expansion method and dynamic flow method vacuum standards and the UHV/XHV vacuum standard. A programmed calibration system for vacuum gauges with a pressure range from 10-4pa to 10^5Pa was also developed for industrial applications. To calibrate the mass spectrometers, an apparatus with three independent and identical gas inlets was developed to measure the standard partial pressures by use of the calibrated SRGs in two different ways, of which the calibration range is from 10^-7Pa to 10^-1Pa. To calibrate the vacuum leaks, a constant pressure flowmeter with the gas flow range from 10-8Pa ·m3/sec to 10-2pa·m3/sec and a constant conductance flowmeter with the gas flow range from 10-18pa·m3/sec to 10-8Pa-m3/sec were developed. The leak rates can be calibrated by calculating the magnitude of the helium ion currents evoked by a QMS on which the leak test was done with the result of a calibrated leak apparatus in comparison with that of a gas flowmeter. Moreover, to calibrate the pressure leaks at atmospheric pressure, a relevant apparatus was developed, of which the gas flowrate range is from 5xl0-SPa-m3/sec to 10-1Pa＇m3/sec, by constant volume method and dynamic comparsion method with quantitative gas. Finally, to calibrate the directional ganges and study the nonuniform molecular flow, a vacuum calibration apparatus for directional flow was developed with a pressure range from 10-7pa to 10- 1Pa.