Structure Design And Output Characteristics Analysis Of Fe-Ga Magnetostrictive Liquid Level Sensor

With the continuous improvement of technology level and industrial demand,the requirement of measuring accuracy and working stability of magnetostrictive liquid level sensor is getting higher and higher.However,the performance of magnetostrictive liquid level sensor on the market,especially the sensor made by domestic companies,is far from meeting the demand.It's particularly important to make magnetostrictive liquid level sensor with higher measurement accuracy and stronger anti-interference ability.A double detection coil structure was designed to solve the problems existing in the traditional structure sensor.The effects of waveguide wire defects,creases and protective tubes on the output characteristics were studied,and the application of the sensor in the field of parameter measurement was discussed.A new structure of magnetostrictive liquid level sensor with double detection coils was designed to overcome the problem that the measuremental results of traditional structure sensor were affected by temperature and excessive impulse current noise.The mathematical models of torsional wave velocity and temperature were established,and the variation trend of torsional wave velocity with temperature was obtained.The suppression effect of the new structure of double detection coil on impulse current noise was analyzed in principle.The calculation model of liquid level height for a new double-detection coil structure was established.The experimental results show that the double detection coil structure can quickly calculate the torsional wave velocity and compensate for the influence of temperature on the measurement results,suppress the impulse current noise and improve the signal-to-noise ratio of the output signal,reduce the sensor measurement error and improve the measurement accuracy.In order to optimize the output characteristics of the sensor and improve its working stability,the effects of surface defects,creases and protective tubes of the waveguide wire were studied.The effects of surface defects at different locations and depths on the output characteristics of the sensor were analyzed.The effects of creases at different locations and degrees of bending on the output characteristics were studied.The effects of contact friction and tension on the output characteristics of the protective tube were discussed.The results show that different defect(crease)locations and the degree of defect(bend)have different effects on the output characteristics.And the contact friction and tension of the protective tube also reduce the amplitude of the torsional wave signal.In order to measure the material parameters accurately and efficiently,according to the output characteristics which can reflect the material parameters of the waveguide wire,the extended application of the sensor in the field of material parameters measurement was explored.On the basis of the working principle of the sensor,the measurement schemes of Poisson's ratio and linear expansion coefficient of the waveguide wire were proposed.The calculation model for measuring Poisson's ratio and the calculation model for linear expansion coefficient were established.And the feasibility of the measurement methods were verified by experiments.The experimental results show that the two measurement schemes are accurate,feasible and easy to operate.The scheme provides a theoretical reference for the development of high performance magnetostrictive liquid level sensor.