A dynamic pressure calibration device based on the low speed servomotor and pistonphone technique

Abstract

The demand for low-frequency low-pressure measurements promotes continuous improvement of the dynamic pressure calibration device. This paper proposes an improved calibration device based on the low-speed servomotor and the pistonphone technique. Specifically, a new membrane-sealing structure between the piston and chamber is developed to substitute the traditional slit-sealing structure, so that the severe pressure leakage loss and friction are avoided. Secondly, a multi-leaf-spring supporting structure is adopted in the servomotor and crank link driving system, which avoided the high cost of using vibrator excitation and in the meanwhile, alleviate the radial bounce of piston. To help finalize the driving system, a theoretical model based on the kinematic and dynamic analysis is built. Finally, a prototype is built to conduct basic performance tests and primary sensor calibrations. The proposed technical and theoretical solutions can be extended to wider frequency and pressure ranges, rather than the given prototype in this paper.