Frequency Sweeping Speed Influence On Calibration Results In Sinusoidal Pressure Dynamic Calibration

Sinusoidal pressure dynamic calibration is widely applied and considered significant in modern industry,particularly in military area.The Swept Frequency Calibration Device,produced by Beijing Aerospace Institute for Metrology and Measurement,has been achieved to calibrate various types of dynamic pressure sensors.The working principle is that the high-pressure cylinder provides working gas and certain pressure for the regulator,from which high-pressure gas is supplied by swept pressure generator after pressure regulation.A special gas flow control nozzle is designed at the entrance of swept pressure generator for fine-tuning gas flow under different working pressures.After the swept pressure generator is sealed,it is connected with the adiabatic exhaust system.Before working,the pressure of the adiabatic exhaust system is pumped to the required magnitude by a vacuum pump,which is monitored by the system control and the data analyzer in real time.The swept pressure generator is controlled by the system and the data analyzer is operated by the motor.The swept pressure is formed in the swept pressure chamber and acts on the symmetrical installation standard sensor.On the quasi-sensor and the measured sensor,the output signals of the two sensors are collected,analyzed and processed by the amplified data analyzer.The calibration data such as the amplitude-frequency characteristic curve,phase-frequency characteristic curve and out-of-band attenuation of the side sensor can be obtained.By comparing the response of the standard pressure sensor and the calibrated pressure sensor in the same sinusoidal pressure source,the dynamic characteristics of the calibrated sensor are calibrated.Currently,there are few theories about the results of calibration and controlling parameters in sweeping working mode.According to the needs in sweeping calibration,three parts of analysis are divided into: Firstly,analysis about the influence of sweeping speed on the sweeping signal which provides the dynamic pressure is considered,in which how the signal is influenced by sweeping frequency is investigated;secondly,analysis on the influence of sweeping speed on the standard sensors is made,in which the principles of choosing an standard sensor or ensuring its safety are given;thirdly,analysis about the influence of sweeping speed on the sampling and data analysis is provided,in which the data processing is mainly analyzed.The influences of sweeping speed on the sweeping calibration is determined by the three parts of analysis above,which ensure the currency of the sinusoidal signal dynamic calibration.