Theoretical And Experimental Study On Pressure Difference Senor With Magnetic Fluid

Magnetic fluid is a new functional material which has both magnetism and fluidity. The application of the unique performance of magnetic fluid on sensor is one of major developed directions such as pressure difference sensor. Based on the production and the research on the performance of magnetic fluid, the magnetic model of magnetic fluid and the model of the pressure difference sensor with magnetic fluid was built and analysed. The relationship between output and input were deduced and the output characteristic of pressure difference sensor with magnetic fluid was analysed. And the sensitivity was also calculated. The design of pressure difference sensor with magnetic fluid was processed. After the coil turns and the current being calculated, the voltage and the frequency of the power were chosen. The configuration of pressure difference sensor with magnetic fluid was designed according to the calculation. Then series of experiments were made and the following is the conclusions from the theory calculation and the experiments.(1) Keeping one kind of magnetic fluid and the power voltage unchanged, with the tube diameter increasing, the optional range of input frequency becomes narrow.(2) The diameter of coil has little effect on the output and the sensitivity of the sensor.(3) With the concentration of magnetic fluid increasing, the optional range of stable frequency becomes narrow, and the output voltage and the sensitivity increases. However, the viscosity of magnetic fluid increases with the density of magnetic fluid increasing, and then the hysteresis of the sensor occurred.(4) Fixing the coil diameter, with the density of magnetic fluid increasing, the saturation magnetization of magnetic fluid increases, and the output voltage and the sensitivity also increase. Besides, the measurable range of the sensor increases with the density of magnetic fluid increasing.(5) The sensitivity of the sensor increases with the thickness of U tube decreasing. When the parameters of magnetic fluid and the U tube are fixed, the sensitivity of pressure difference sensor is proportional to the input voltage.Besides, the measurable range of the pressure difference sensor designed increases with the length of tube and the height of magnetic fluid core in the tube increasing.