Study And Application On Vacuum Reference Leak Standard Device

In this paper, a method for setting up the standard leak calibration device is introduced by using small orifice and quadrupole mass spectrometer.In this paper, the basic characteristic of the orifice conductance has been studying, and the formula of orifice conductance variaty with pressure is given. The calculation method of small orifice conductance is introduced in this paper. The small orifice conductance is measured by constant pressure method, and its uncertainty is evaluated.After small orifice conductance is determined, the flow through the small orifice only contact with pressure of the ballast chamber. To eliminate the measurement error caused by non-linearity of quadrupole mass spectrometer and its poor of the long-term stability, the gas pressure in ballast camber can be adjusted precisely to make gas flow through the orifice very near or equal to the lead rate of calibrated vacuum leak.The gas pressure in ballast chamber is high enough that pure single gas can be realized by no strict material disposal and no bakeout. The calibration leak rate rang of this devic varies from 10^-10 Pa·m³/s to 10^-5 Pa·m³/s. The evaluated uncertainty is 2.2%, which can be further decreased through precisely calibrating capacitance diaphragm gauge and controlling temperature., etc.By experimental research, the measurement error caused by non-linearity of quadrupole mass spectrometer is up to 38%, affected its measurement performance.