Global model of the gas flow in high-vacuum standards

摘要

The non-uniformity of the gas number density distributions in high-vacuum standards based on continuous gas expansion may be the cause of the differences that occur between the gas number density generated in the gauge to be calibrated and its value calculated using traditional methods. It may be the source of certain systematic errors of these standards. This paper presents a gas flow model that permits determining the gas number density directly within the volume of the gauge to be calibrated as a function of the gas flux that flows through the calibration chamber. The proposed model takes into account the whole geometrical complexity of the standard, thus minimizing the drawbacks of the traditional model. Examples of possible applications are also discussed in this paper.