Dynamic response characteristics of vacuum pressure measurement system with pneumatic long-thin tube

Abstract The pneumatic long-thin tube between a measured pressure source and pressure sensor is a key component of a vacuum pressure measurement system (VPMS). The dynamic response characteristics of a pneumatic long-thin tube significantly affects the accuracy of the VPMS. This paper presents a mathematical model of the pressure propagation in a VPMS. The mathematical model accounts for the effects of fluid viscosity and heat transfer. A method for testing dynamic response characteristics of the VPMS is proposed. The sinusoidal vacuum pressure signal source was generated by a device consisting of a closed chamber and a loudspeaker. A series of tests were carried out using pneumatic long-thin tube with diameters of 2 and 3 mm, lengths of 100 and 300 mm, and initial vacuum pressures of 3.3 and 30 kPa. The comparison of the experimental and mathematical simulation results demonstrated that the mathematical model could accurately describe the dynamic response characteristics of the VPMS within certain frequency and pressure ranges. The results of this paper have general implications for the design and analysis of the VPMSs.