Study On A Novel Sinusoidal Pressure Generator Based On Magnetic Liquid

With the rapid development of science and technology, sensor technology is one of the quickest developed technology in the world. Micro differential pressure transformer is one of the instruments widely applied for detection. The dynamic calibration method is necessary to understand the dynamic characteristics of the micro differential pressure transformer. Sinusoidal pressure signal, one of the periodic signals, which is commonly used in dynamic pressure calibration. Through it, we can accurately get the amplitude-frequency characteristic and phase- frequency characteristic of the micro differential pressure transformer.Magnetic liquids, a new function material, is a stable colloidal solution mixed with strong magnetic nanoparticles, base solution and surfactant, possessing both magnetism characteristic of solid magnetic material and fluidity of the liquid. As the unique features of the magnetic liquids, it is used in many fields, for example: mechanical seal, damper, and sensor. However, it is a new application to put the magnetic liquids in the dynamic calibration of the micro differential pressure transformer.In this thesis, supported by the Nature Science Foundation of Hebei Province(No.E2008000050)and Nature Science Foundation of China (No.51077037), a novel sinusoidal pressure generator with low frequency (0.1Hz~100Hz) based on magnetic liquids has been demonstrated by theory and experiment, whose principle, structure and experimental results are presented in detail. The main research work is as following. The functional relation between input electrical signal and output pressure signal is given in this paper. Meanwhile, the structural model of the generator is setup and the experimental platform is also built for it. In addition, the distribution of magnetic field in the generator is analyzed. Both the simulation results and the experiment results prove that this kind of new sinusoidal pressure generator is logical. The sinusoidal pressure waveform, produced by the generator, with high precision of amplitude and low distortion can be used in the dynamic calibration of micro differential pressure transformer.