The Design of a(10⁵~10^-8) Pa Vacuum Gauge Calibration Apparatus

Aiming at the one-time calibration requirement of compound vacuum gauge with the range of(10⁵~10^-8) Pa,a corresponding calibration apparatus is designed.The apparatus is mainly composed of a calibration chamber,a vacuum measurement module,a pumping and gas supply module,a standard flowmeter,and a baking module.The designed calibration chamber is a spherical vessel,which is pumped by a series of molecular pumps and ion pump to obtain the ultimate vacuum degree of 10^-9 Pa in the calibration chamber.The calibration is realized by the static comparison method,the dynamic comparison method,and the standard flow method.The static comparison method uses a capacitance diagram gauges(CDG) as the reference standard to achieve the calibration range of(10⁵~10^-1) Pa.The dynamic comparison method uses a spinning rotor gauge(SRG) as the reference standard to achieve the calibration range of(10^-1~10^-4) Pa.The standard gas flow method adopts a(10^-5~10^-9) Pa·m³/s standard gas flowmeter to provide the standard gas flow rate and achieve the calibration range of(10^-4~10^-8) Pa.The calibration range of the designed apparatus is(10⁵~10^-8) Pa with a combined standard uncertainty of 0.9%~2.3%,which solves the technical problem of one-time calibration for wide-range vacuum gauges.