Abstract:
In the industrial and scientific fields, such as semiconductor fabrication and space environment simulation, high-precision vacuum pressure measurement is critically required for inert gases including argon (Ar), krypton (Kr), and xenon (Xe), which are characterized by their relatively high molecular masses and viscosities. The Spinning Rotor Gauge (SRG) is widely employed for such measurements due to its high accuracy and reliability. This study focuses on the experimental calibration of the effective tangential momentum accommodation coefficient (
σeff) for three distinct models of spinning rotor gauges (SRGs) under inert conditions, based on the static expansion method—a primary standard technique for vacuum pressure generation. The calibration process was systematically conducted to determine the
σeff values, and the stability of the measurement results was thoroughly analyzed. Furthermore, a comprehensive evaluation of the measurement uncertainty was performed. The experimental results indicate that within the pressure range of 1×10
−4 Pa to 1 Pa, the SRG-2CE model demonstrates the best measurement stability for krypton (Kr), showing a
σeff deviation ranging from −0.92% to 1.68%. The calibrated
σeff values obtained from the three different SRG models for Ar, Kr, and Xe are 0.992, 0.984, and 0.999, respectively. These values reflect the gases' interaction with the rotor surface and are crucial for accurate pressure reading conversion. The study identifies that the main sources of measurement uncertainty include inaccuracies in the pre-pressure measurement, uncertainties associated with the calibration of the volume ratio in the expansion system, and inherent deviations of the spinning rotor gauges themselves. In the high-vacuum range, the relative combined standard uncertainty is found to vary between 0.77% and 3.31%, decreasing as pressure increases. This research provides essential calibration data for the application of SRGs for measuring heavy inert gases, thereby enhancing measurement reliability in advanced technological processes where precise vacuum control is imperative.