Abstract:Magnetic liquid can replace solid elastic element with its unique second-order suspension force to provide the inertial element of the dip sensor with a flexible elastic force, which can greatly improve the impact resistance of the dip sensor. It has been successfully applied in petroleum exploration industry. To improve the sensitivity of the magnetic liquid dip sensor, a new structure and detection method is proposed based on the second-order suspension characteristics of magnetic liquid. The spatial distribution of magnetic field between two permanent magnets is calculated by the theory, and the static performance of the sensor with different parameters is analyzed by experiment comparisons. Results show that when the lateral clearance is 3 mm and the amount of magnetic fluid is 1. 4 g, the measurement range is 0° ~ 50°, the linearity error is 1. 004 7% , the response rate is 2. 3 mV/ °, the resolving power is 0. 023°, the repeatability error is 3. 18% , and the working performance of the sensor is the best. In addition, the performance-price-ratio index of the sensor is high and the material of the housing is environmental, which makes it has a good practical application value.