静态膨胀法真空标准校准下限延伸方法研究

Lower Limit Extension of Static Expansion Vacuum Standard

影响静态膨胀法真空标准校准下限的主要因素是器壁放气,本文提出了使用非蒸散型吸气剂泵(NEGP)消除器壁放气影响来延伸校准下限的方法。NEGP对惰性气体无抽速,当以惰性气体作为校准气体时,NEGP既维持了校准室中的超高真空本底,又不改变校准室内惰性气体的气体量,从而保证气体静态膨胀时波义耳定律严格成立,使标准压力能够准确计算。这种方法将静态膨胀法真空标准校准能力的下限延伸到了10-7Pa量级。

A novel technique has been successfully developed to extend the lower limit of the static expansion vacutun standard in high vacuum calibration. In the technique, non-evaporable getter pump （NEGP） was used to reduce the impact of out-gassing of the vacuum chamber inner-walls,not only because it cannot pump inert gases used in the calibration,but also because it maintains the base pressure in ultra high vacuum （UHV）. As a result, the standardized pressure can be calculated with high precision by means of Boyle law in the static expansion. The lower limit of the static expansion vacuum standard was successfully extended to 10^-7pa.