High-precision anti-interference pressure transmitter

Abstract

The application relates to the technical field of pressure transmitters, and discloses a high-precision anti-interference pressure transmitter, which comprises a transmitter shell and a transmitter front cover arranged at the front end of the transmitter shell, the rear end of the transmitter shell is provided with a transmitter rear cover, further comprises a locking ring fixed below the transmitter shell, the temperature compensation scheme of the application realizes core advantages through cooperation of multiple components, efficiently conducts fluid temperature of a measuring channel, ensures real-time synchronization and no lag of compensation and temperature change, precisely offsets temperature drift of a strain resistance of a pressure sensor, avoids signal false high or false low, guarantees measurement precision, and adjusts the current of a ring-shaped electromagnet of a stable circuit board to optimize a magnetic field, realizes basic compensation outside -40 DEG C to 125 DEG C, and expands temperature range adaptability; the whole discards a traditional electronic compensation scheme, has no additional power consumption and is strong in anti-electromagnetic interference, the mechanical structure cooperatively guarantees long-term stable compensation, and significantly improves measurement reliability of the pressure transmitter and adaptability to complex environments.

Description

Technical Field

[0001] This invention relates to the field of pressure transmitter technology, and specifically to a high-precision, anti-interference pressure transmitter. Background Technology

[0002] In the field of industrial fluid (gas, liquid) pipeline pressure monitoring, pressure transmitters are core equipment for ensuring stable production processes. They need to continuously output high-precision measurement data under complex operating conditions such as temperature fluctuations, pipeline vibration, and installation stress. As industrial production demands higher precision in process control, the shortcomings of traditional pressure transmitters in adapting to complex operating conditions and maintaining long-term measurement stability are becoming increasingly apparent.

[0003] The technical shortcomings of existing pressure transmitters are as follows:

[0004] First, the temperature compensation effect is not good. Current solutions mostly rely on electronic compensation algorithms or thermistors to correct temperature drift. Electronic compensation has a response lag problem and is easily affected by environmental electromagnetic interference, which affects accuracy. It also requires additional power to maintain operation. Thermistors have poor linearity, narrow temperature range, and are prone to compensation failure under extreme temperatures. They cannot stably offset the false high or low signals caused by temperature changes, making it difficult to meet the requirements of wide temperature range measurement.

[0005] Secondly, the ability to resist lateral interference is weak. For lateral forces generated by pipeline vibration or installation stress, existing solutions mostly use rigid limiting or electronic signal correction. Rigid limiting will generate additional stress with the main body of the equipment, which will damage the measurement reference; electronic correction has a delayed response and cannot offset the measurement deviation caused by lateral forces in real time, resulting in a decrease in accuracy.

[0006] Third, it is difficult to achieve both vibration isolation and signal fidelity. Existing anti-vibration solutions mostly rely on elastic components such as rubber and springs for buffering. These components are prone to fatigue and aging, and their buffering effect diminishes after long-term use. They also easily lead to distortion of pressure signals, making it impossible to achieve both effective vibration isolation and distortion-free transmission of static pressure signals at the same time.

[0007] Existing solutions often separate temperature compensation and anti-interference functions into separate designs, resulting in low integration, poor adaptability to complex working conditions with multiple factors, and insufficient long-term operational reliability, making it difficult to meet the industrial sector's demand for high-precision and high-stability pressure monitoring. Summary of the Invention

[0008] This invention provides a high-precision, anti-interference pressure transmitter that offers reliable measurements and adaptability to complex environments.

[0009] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0010] In a first aspect, a high-precision, anti-interference pressure transmitter includes: a transmitter housing and a transmitter front cover disposed at the front end of the transmitter housing, and a transmitter rear cover disposed at the rear end of the transmitter housing; further comprising:

[0011] A locking ring is fixed to the bottom of the transmitter housing; a measurement channel is opened inside the locking ring; a pressure sensor is fixed inside the measurement channel; a sensor base is fixed inside the measurement channel and located directly above the pressure sensor; a temperature compensation component is fixed inside the measurement channel and located between the pressure sensor and the sensor base; and a correction component is fixed inside the measurement channel and located above the sensor base.

[0012] A ring electromagnet is fixed inside the measurement channel and located directly below the sensor base; a thermistor magnetic alloy sheet is fixed inside the measurement channel and located directly below the ring electromagnet; a miniature elastic support is fixed between the ring electromagnet and the thermistor magnetic alloy sheet; a rubber sealing ring is fixed above the thermistor magnetic alloy sheet and below the pressure sensor.

[0013] The correction groove is located above the sensor base; the cylindrical electromagnet is fixed inside the measurement channel; the elastic U-shaped plate is fixed on one side of the sensor base and on the cylindrical electromagnet at the other end; the slot is located on the elastic U-shaped plate and fits onto the cylindrical electromagnet; the permanent magnet is fixed on the side of the elastic U-shaped plate near the sensor base.

[0014] Furthermore, it also includes:

[0015] An elastic retaining ring is fixed inside the transmitter front cover; a window is fixed inside the elastic retaining ring; two first O-rings are provided, with the two first O-rings respectively fitted onto the transmitter front cover and the transmitter rear cover; a second O-ring is fitted onto the locking ring; an explosion-proof junction box is fixed above the transmitter housing; explosion-proof plugs are fixed at both ends of the explosion-proof junction box; a third O-ring is fitted onto the explosion-proof plugs and is located between the explosion-proof junction box and the explosion-proof plugs.

[0016] Furthermore, it also includes:

[0017] The circuit board is fixed inside the transmitter housing; the circuit panel is fixed inside the transmitter housing and located on one side of the transmitter front cover; the wiring terminals are fixed to the circuit board; the connecting wire is fixed at one end to the circuit board and at the other end to the pressure sensor; the flame-retardant epoxy resin is fixed inside the sensor base and to the connecting wire.

[0018] Furthermore, it also includes:

[0019] Set screw, threaded into the bottom of the transmitter housing, with the screw end extending to the outside of the locking ring; grounding terminal, fixed inside the explosion-proof junction box; plate-shaped nameplate, fixed above the explosion-proof junction box; pan head screw, threaded end penetrating the plate-shaped nameplate and screwed into the explosion-proof junction box; curved nameplate, fixed below the transmitter housing.

[0020] Furthermore, the positioning distance between the sensor base and the annular electromagnet is 1 mm, the magnetic circuit gap between the annular electromagnet and the thermistor magnetically conductive alloy sheet is 0.3 to 0.5 mm, and the air gap between the thermistor magnetically conductive alloy sheet and the elastic diaphragm of the pressure sensor is 0.2 to 0.3 mm.

[0021] Furthermore, the magnetic pole above the annular electromagnet is the S pole, and the magnetic pole below the annular electromagnet is the N pole.

[0022] Furthermore, the thermistor magnetically conductive alloy sheet is made of Ni45 alloy, and the elastic diaphragm compensation force transmitted from the thermistor magnetically conductive alloy sheet to the pressure sensor is 0.01 to 0.1 N.

[0023] Furthermore, the micro elastic support is provided in three parts, and the three micro elastic supports are distributed at equal angles around the annular electromagnet as the axis.

[0024] Furthermore, the miniature elastic support is a 0.2mm thick permalloy sheet, arranged in an inverted V shape.

[0025] Furthermore, the length of the miniature elastic support is 0.5 mm, and the elastic coefficient is calibrated to be 1-2 N / mm.

[0026] The above-described solution of the present invention has at least the following beneficial effects:

[0027] The temperature compensation scheme of this invention achieves its core advantages through the collaborative operation of multiple components. The measurement channel efficiently transmits the temperature of the pipeline fluid, ensuring that compensation is synchronized with temperature changes in real time without lag. The temperature drift of the strain gauge of the pressure sensor is precisely canceled, avoiding false high or low signals and ensuring stable measurement accuracy. The permeability of the thermistor magnetic alloy sheet, which changes linearly with temperature, provides the basis for compensation. Combined with a 0.3-0.5mm magnetic circuit gap between the annular electromagnet and the thermistor magnetic alloy sheet, the magnetic flux density of the magnetic circuit is precisely adjusted with temperature, and compensation is triggered by changes in magnetic attraction force. The miniature elastic support stably drives the deformation of the thermistor magnetic alloy sheet, keeping the compensation force controllable at 0. The range is 0.1 to 0.1 N; the extremely narrow air gap of 0.2 to 0.3 mm between the thermistor magnetic alloy sheet and the elastic diaphragm of the pressure sensor, combined with near-field magnetic coupling and force field transmission, allows the compensation force to be accurately applied to the strain resistance area at the center of the diaphragm, avoiding force transmission deviation; under extreme temperatures, the circuit board can adjust the current of the ring electromagnet to optimize the magnetic field, avoiding over- or under-compensation, achieving basic compensation beyond -40℃ to 125℃, and expanding the temperature range adaptability; the entire system abandons the traditional electronic compensation scheme, with no additional power consumption and strong resistance to electromagnetic interference. This mechanical structure works together to ensure long-term stable compensation, significantly improving the measurement reliability and adaptability of the pressure transmitter to complex environments.

[0028] This invention achieves efficient anti-interference and measurement accuracy through multi-component collaboration. When pipeline vibration or installation stress causes lateral force to shift the sensor base, the correction component can quickly correct it. The cylindrical electromagnet and permanent magnet are magnetically attracted during radial correction, and the difference in magnetic attraction generates a reverse reset torque to pull the sensor base back. Combined with the deformation capability of the elastic U-shaped plate, the slot ensuring connection stability, and the correction groove providing deformation space, it achieves contactless and lag-free radial correction, replacing traditional rigid limiting and electronic compensation methods, avoiding additional stress and response delay, and protecting the measurement accuracy of the pressure sensor. External vibration or impact passes through the transmitter housing, transmitter front cover, transmitter front cover, and locking ring. When transmitted to the measurement channel, the elastic magnetic repulsion gap formed by the opposite poles of the magnetic ring in the correction component plays a buffering role. The nonlinear magnetic repulsion increases sharply when the axial spacing decreases, and the resistive stress is transmitted to the pressure sensor and temperature compensation component, avoiding damage to the sensitive element or measurement error. Moreover, the static pressure of the pipeline is transmitted to the pressure sensor without distortion through magnetic coupling, realizing vibration isolation and signal fidelity. The cylindrical electromagnet can adjust the magnetic field by adjusting the current through the circuit board. It can adjust the reset torque according to the lateral force intensity, calibrate the initial balance to ensure zero offset of the sensor base, and adjust the magnetic field in stages to adapt to the pipeline vibration frequency, avoiding resonance that causes correction failure. This comprehensively improves the stability and reliability of the pressure transmitter under complex working conditions. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall structure of a high-precision anti-interference pressure transmitter provided in an embodiment of the present invention;

[0030] Figure 2A planar sectional view of the transmitter housing of a high-precision anti-interference pressure transmitter provided in an embodiment of the present invention;

[0031] Figure 3 A planar sectional view of a sensor base for a high-precision anti-interference pressure transmitter provided in an embodiment of the present invention;

[0032] Figure 4 A high-precision anti-interference pressure transmitter provided in this embodiment of the invention. Figure 3 Enlarged view of point A;

[0033] Figure 5 A partial cross-sectional view of an explosion-proof junction box for a high-precision anti-interference pressure transmitter provided in an embodiment of the present invention;

[0034] Figure 6 A front view of a high-precision anti-interference pressure transmitter provided in an embodiment of the present invention;

[0035] Figure 7 An overall top view of a high-precision anti-interference pressure transmitter provided in an embodiment of the present invention;

[0036] Figure 8 This is a schematic diagram of the elastic U-shaped plate structure of a high-precision anti-interference pressure transmitter provided in an embodiment of the present invention.

[0037] Explanation of reference numerals in the attached figures:

[0038] In the diagram: 1. Transmitter housing; 2. Transmitter front cover; 3. Transmitter rear cover; 4. Locking ring; 5. Measurement channel; 6. Pressure sensor; 7. Sensor base; 8. Temperature compensation component; 801. Ring electromagnet; 802. Thermistor magnetic alloy sheet; 803. Miniature elastic support; 804. Rubber sealing ring; 9. Correction component; 901. Correction groove; 902. Cylindrical electromagnet; 903. Elastic U-shaped sheet; 904. Slot; 90 5. Permanent magnet; 10. Elastic retaining ring; 11. Window; 12. First O-ring; 13. Second O-ring; 14. Explosion-proof junction box; 15. Explosion-proof plug; 16. Third O-ring; 17. Circuit board; 18. Circuit panel; 19. Terminal block; 20. Connecting wire; 21. Flame-retardant epoxy resin; 22. Set screw; 23. Grounding terminal; 24. Plate nameplate; 25. Pan head screw; 26. Curved nameplate. Detailed Implementation

[0039] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0040] like Figures 1 to 8 As shown, an embodiment of the present invention provides a high-precision anti-interference pressure transmitter, including: a transmitter housing 1 and a transmitter front cover 2 disposed at the front end of the transmitter housing 1, and a transmitter rear cover 3 disposed at the rear end of the transmitter housing 1, and further including:

[0041] Locking ring 4 is fixed below transmitter housing 1; measuring channel 5 is opened inside locking ring 4; pressure sensor 6 is fixed inside measuring channel 5; sensor base 7 is fixed inside measuring channel 5 and located directly above pressure sensor 6; temperature compensation component 8 is fixed inside measuring channel 5 and located between pressure sensor 6 and sensor base 7; correction component 9 is fixed inside measuring channel 5 and located above sensor base 7.

[0042] An annular electromagnet 801 is fixed inside the measurement channel 5 and located directly below the sensor base 7; a thermistor magnetic alloy sheet 802 is fixed inside the measurement channel 5 and located directly below the annular electromagnet 801; a miniature elastic support 803 is fixed between the annular electromagnet 801 and the thermistor magnetic alloy sheet 802; a rubber sealing ring 804 is fixed above the thermistor magnetic alloy sheet 802 and below the pressure sensor 6; a correction groove 901 is formed above the sensor base 7; a cylindrical electromagnet 902 is fixed inside the measurement channel 5; an elastic U-shaped sheet 903 is fixed on one side of the sensor base 7 and on the cylindrical electromagnet 902 at the other end; a slot 904 is formed on the elastic U-shaped sheet 903 and fits onto the cylindrical electromagnet 902; and a permanent magnet 905 is fixed on the side of the elastic U-shaped sheet 903 closest to the sensor base 7.

[0043] It also includes: an elastic retaining ring 10, fixed inside the transmitter front cover 2; a window 11, fixed inside the elastic retaining ring 10; two first O-rings 12, which are respectively fitted onto the transmitter front cover 2 and the transmitter rear cover 3; a second O-ring 13, fitted onto the locking ring 4; an explosion-proof junction box 14, fixed above the transmitter housing 1; an explosion-proof plug 15, fixed at both ends of the explosion-proof junction box 14; and a third O-ring 16, fitted onto the explosion-proof plug 15 and located between the explosion-proof junction box 14 and the explosion-proof plug 15.

[0044] It also includes: a circuit board 17, fixed inside the transmitter housing 1; a circuit panel 18, fixed inside the transmitter housing 1, located inside one side of the transmitter front cover 2; a terminal block 19, fixed on the circuit board 17; a connecting wire 20, one end fixed on the circuit board 17 and the other end fixed on the pressure sensor 6; and flame-retardant epoxy resin 21, fixed inside the sensor base 7 and fixed on the connecting wire 20.

[0045] It also includes: a set screw 22, threaded into the lower part of the transmitter housing 1, with the screw end extending to the outside of the locking ring 4; a grounding terminal 23, fixed inside the explosion-proof junction box 14; a plate-shaped nameplate 24, fixed above the explosion-proof junction box 14; a pan head screw 25, with the threaded end passing through the plate-shaped nameplate 24 and screwed into the explosion-proof junction box 14; and a curved nameplate 26, fixed below the transmitter housing 1.

[0046] Specifically, the center of the sensor base 7 is hollow; four correction components 9 are provided, distributed at equal angles on the sensor base 7; the window 11 is made of tempered glass; the first O-ring 12, the second O-ring 13, and the third O-ring 16 are made of nitrile rubber; the connecting wire 20 must have anti-electromagnetic interference capability, and the connecting wire 20 enters the flame-retardant epoxy resin 21 to play a role in fixing and flame retardancy. The connecting wire 20 exits from the outside of the flame-retardant epoxy resin 21, and without affecting the temperature compensation component 8 and the correction component 9, it enters the wall of the locking ring 4 and then makes an electrical connection with the pressure sensor 6. The sheet-shaped label 24 and the curved label 26 are used to mark key information such as equipment parameters and model, which facilitates installation and maintenance identification.

[0047] In another preferred embodiment of the present invention, the positioning distance between the sensor base 7 and the annular electromagnet 801 is 1 mm, the magnetic circuit gap between the annular electromagnet 801 and the thermistor magnetic alloy sheet 802 is 0.3 to 0.5 mm, and the air gap between the thermistor magnetic alloy sheet 802 and the elastic diaphragm of the pressure sensor 6 is 0.2 to 0.3 mm.

[0048] The magnetic pole above the ring electromagnet 801 is the S pole, and the magnetic pole below the ring electromagnet 801 is the N pole; the thermistor magnetically conductive alloy sheet 802 is made of Ni45 alloy, and the elastic diaphragm compensation force transmitted by the thermistor magnetically conductive alloy sheet 802 to the pressure sensor 6 is 0.01~0.1N; three miniature elastic legs 803 are provided, and the three miniature elastic legs 803 are equally distributed around the ring electromagnet 801 as the axis; the miniature elastic legs 803 are 0.2mm thick permalloy sheets, arranged in an inverted V shape, with a length of 0.5mm and an elastic coefficient calibrated to 1~2N / mm.

[0049] After the pressure transmitter is installed on the gas or water pipe, the locking ring 4 is fixed to the bottom of the transmitter housing 1 by the set screw 22. The second O-ring 13 ensures the sealing performance between the locking ring 4 and the transmitter housing 1. The front cover 2 and the rear cover 3 of the transmitter are sealed at both ends of the transmitter housing 1 by the first O-ring 12. The elastic retaining ring 10 fixes the window 11 inside the front cover 2 of the transmitter to achieve overall sealing protection of the equipment.

[0050] The explosion-proof junction box 14 is fixed above the transmitter housing 1. The explosion-proof plug 15 seals both ends of the explosion-proof junction box 14 through the third O-ring 16. The grounding terminal 23 is installed inside the explosion-proof junction box 14 to eliminate electrostatic interference. The sheet-shaped nameplate 24 is fixed above the explosion-proof junction box 14 by pan head screws 25. The curved nameplate 26 is fixed below the transmitter housing 1, completing the equipment identification and safety protection configuration.

[0051] The fluid pressure inside the pipeline acts on the elastic diaphragm of the pressure sensor 6, causing the elastic diaphragm to deform and causing a change in the resistance value of the surface strain resistor. The connecting line 20 transmits the resistance change signal to the circuit board 17. The circuit panel 18, together with the terminal block 19, completes the initial signal processing. The flame-retardant epoxy resin 21 fixes the connecting line 20 to prevent vibration from causing abnormal signal transmission, thus realizing the basic pressure measurement function. The 1mm positioning gap between the sensor base 7 and the annular electromagnet 801 ensures the stability of the magnetic circuit. When the annular electromagnet 801 is within the normal operating range, the magnetic field strength of the annular electromagnet 801 remains at the set value.

[0052] When the temperature rises, the heat from the fluid in the pipe is conducted to the measuring channel 5, causing the resistance of the strain gauge of the pressure sensor 6 to increase, resulting in a false high signal. This temperature also affects the thermistor magnetic alloy sheet 802, causing a linear decrease in its permeability. The magnetic field generated by the ring electromagnet 801 passes through the thermistor magnetic alloy sheet 802 to form a closed magnetic circuit. The decrease in permeability reduces the magnetic flux density in the magnetic circuit, weakening the magnetic attraction of the ring electromagnet 801 on the thermistor magnetic alloy sheet 802. Due to its calibration elastic coefficient of 1-2 N / mm, the inverted V-shaped structure of the miniature elastic support 803 elastically stretches when the magnetic attraction weakens. An extremely narrow air gap of 0.2-0.3 mm remains between the thermistor magnetic alloy sheet 802 and the elastic diaphragm of the pressure sensor 6. The inner edge of the thermistor magnetic alloy sheet 802 is directly opposite the strain gauge of the center of the elastic diaphragm. In the region where the downward-deformed thermistor magnetic alloy sheet 802 is located, the thrust is precisely applied to the surface of the elastic diaphragm through near-field magnetic coupling and a force field transmission method with a small gap. The rubber sealing ring 804 ensures the sealed isolation between the thermistor magnetic alloy sheet 802 and the pressure sensor 6 during the deformation process. The thermistor magnetic alloy sheet 802 transmits a compensation force of 0.01 to 0.1 N through an air gap of 0.2 to 0.3 mm between itself and the elastic diaphragm of the pressure sensor 6. This thrust acts on the central region of the elastic diaphragm, causing the elastic diaphragm to overcome its own elastic resistance and produce a corresponding small deformation downward, thereby changing the stress state of the strain resistor and forming an adjustment amount opposite to the resistance increment caused by temperature. This allows the pressure measurement signal to return to accuracy. Through this purely mechanical magnetic compensation structure, the traditional electronic compensation algorithm and thermistor scheme are abandoned, achieving power-free, real-time response temperature drift correction and effective anti-interference.

[0053] When the ambient temperature decreases, the permeability of the thermistor magnetic alloy sheet 802 increases. The magnetic pole design of the ring electromagnet 801 with the upper S pole and the lower N pole, combined with the 0.3-0.5mm magnetic circuit gap between the ring electromagnet 801 and the thermistor magnetic alloy sheet 802, increases the magnetic flux density in the magnetic circuit formed by the ring electromagnet 801 and the thermistor magnetic alloy sheet 802. The magnetic attraction between the ring electromagnet 801 and the thermistor magnetic alloy sheet 802 is enhanced, overcoming the elastic force of the miniature elastic support 803 and pulling the thermistor magnetic alloy sheet 802 to deform in the opposite direction. Through the air gap, a reverse pulling force is applied to the elastic diaphragm of the pressure sensor 6. This pulling force acts on the central region of the elastic diaphragm, causing the elastic diaphragm to undergo a slight upward deformation. This causes the strain gauge of the elastic diaphragm to adjust its stress state in the opposite direction to reduce its resistance, offsetting the resistance decay of the strain gauge due to the decrease in temperature, and achieving adaptive compensation across the entire temperature range.

[0054] The magnetic field strength of the ring electromagnet 801 can be adjusted by the current signal output from the circuit board 17: In extreme low temperature environments, the input current can be increased to enhance the magnetic field strength, ensuring that the magnetic attraction force on the thermistor magnetic alloy sheet 802 is sufficient to pull the elastic diaphragm to produce effective deformation, thus avoiding insufficient compensation force; In extreme high temperature environments, the input current can be reduced to decrease the magnetic field strength, preventing residual magnetic attraction force from causing excessive compensation; Through this dynamic magnetic field adjustment, the temperature compensation component 8 can be adapted to a wide temperature operating range of -40℃ to 125℃, expanding the environmental adaptability of the equipment.

[0055] When pipeline vibration or installation stress generates lateral force, the lateral force may cause a slight displacement of the sensor base 7, thereby affecting the measurement accuracy of the pressure sensor 6. The magnetic interaction between the cylindrical electromagnet 902 and the permanent magnet 905 in the correction component 9 changes. During the radial correction process, the cylindrical electromagnet 902 and the permanent magnet 905 are magnetically attracted to each other. The elastic U-shaped piece 903 deforms due to its own elastic properties. The slot 904 ensures the connection stability between the elastic U-shaped piece 903 and the cylindrical electromagnet 902. The correction groove 901 provides adaptation space for the deformation of the elastic U-shaped piece 903. The difference in magnetic attraction between the cylindrical electromagnet 902 and the permanent magnet 905 forms a reverse reset torque, pulling the sensor base 7 back to the initial equilibrium position and dynamically canceling the interference of the radial lateral force. This replaces the traditional rigid limit and electronic compensation anti-interference method, realizing contactless and lag-free radial correction, avoiding the additional stress caused by mechanical contact and the response delay of electronic components.

[0056] When external vibration or impact is transmitted to the measuring channel 5 through the transmitter housing 1, transmitter front cover 2, transmitter rear cover 3, and locking ring 4, the elastic magnetic repulsion gap formed by the opposite poles of the magnetic rings in the correction component 9 plays a buffering role. The magnetic repulsion force exhibits nonlinear characteristics as the spacing between components changes. When vibration causes the axial spacing to decrease, the magnetic repulsion force increases sharply, hindering the direct transmission of mechanical stress to the pressure sensor 6 and temperature compensation component 8, thus preventing damage to the sensitive elements or measurement errors due to impact. Meanwhile, the pipeline pressure, as a static force, can be transmitted to the pressure sensor 6 without distortion through the force transmission characteristics of magnetic coupling. This achieves the dual effects of vibration isolation and signal fidelity. The cylindrical electromagnet 902 can change the magnetic field strength by adjusting the input current through the circuit board 17. It can dynamically adjust the reset torque according to the intensity of lateral force interference. The greater the interference, the greater the current and the stronger the magnetic field, thus improving the reset force and the adaptability of the correction. The initial magnetic attraction balance can be precisely finely adjusted during the equipment calibration stage to ensure that the sensor base 7 is in the zero offset reference position, reducing the impact of initial installation error on measurement accuracy. Furthermore, by adjusting the magnetic field strength in stages, it can be adapted to the vibration frequency characteristics of different pipelines, avoiding correction failure caused by resonance.

[0057] The pressure transmitter is designed to operate within a temperature range of -40℃ to 125℃, as follows:

[0058] As the temperature gradually increases from 25℃ to 85℃, the heat from the fluid in the pipe is conducted to the measuring channel 5, causing an increase in the resistance of the strain gauge of the pressure sensor 6, resulting in a false high signal. This temperature also affects the thermistor magnetic alloy sheet 802, causing a linear decrease in its permeability. The magnetic field generated by the ring electromagnet 801 passes through the thermistor magnetic alloy sheet 802 to form a closed magnetic circuit. The decrease in permeability causes a corresponding decrease in the magnetic flux density in the magnetic circuit, weakening the magnetic attraction between the ring electromagnet 801 and the thermistor magnetic alloy sheet 802. The miniature elastic support 803, with its calibrated elastic coefficient of 1-2 N / mm, elastically extends its inverted V-shaped structure when the magnetic attraction weakens. An extremely narrow air gap of 0.2-0.3 mm remains between the thermistor magnetic alloy sheet 802 and the elastic diaphragm of the pressure sensor 6. The inner edge of the thermosensitive magnetic alloy sheet 802 is directly opposite the strain resistance region at the center of the elastic diaphragm. The downwardly deforming thermosensitive magnetic alloy sheet 802 will precisely apply the thrust to the surface of the elastic diaphragm through near-field magnetic coupling and a force field transmission method with a small gap. The rubber sealing ring 804 ensures the sealed isolation between the thermosensitive magnetic alloy sheet 802 and the pressure sensor 6 during the deformation process. The thermosensitive magnetic alloy sheet 802 transmits a compensation force of 0.01 to 0.1 N through an air gap of 0.2 to 0.3 mm between itself and the elastic diaphragm of the pressure sensor 6. This thrust acts on the central region of the elastic diaphragm, causing the elastic diaphragm to overcome its own elastic resistance and produce a corresponding small deformation downward, thereby changing the stress state of the strain resistance and forming an adjustment amount opposite to the resistance increment caused by temperature, so that the pressure measurement signal returns to accuracy. This purely mechanical magnetic compensation structure abandons the traditional electronic compensation algorithm and thermistor scheme.

[0059] As the temperature gradually decreases from 85℃ to -10℃, the permeability of the thermistor magnetic alloy sheet 802 increases. The magnetic pole design of the ring electromagnet 801 with its upper S pole and lower N pole, combined with the 0.3-0.5mm magnetic circuit gap between the ring electromagnet 801 and the thermistor magnetic alloy sheet 802, increases the magnetic flux density in the magnetic circuit formed by the ring electromagnet 801 and the thermistor magnetic alloy sheet 802. This strengthens the magnetic attraction between the ring electromagnet 801 and the thermistor magnetic alloy sheet 802, overcoming the elastic force of the miniature elastic support 803 and causing the thermistor magnetic alloy sheet 802 to deform in the opposite direction. Through the air gap, a reverse pulling force is applied to the elastic diaphragm of the pressure sensor 6. This pulling force acts on the central region of the elastic diaphragm, causing the elastic diaphragm to undergo a slight upward deformation. This causes the strain gauge of the elastic diaphragm to adjust its stress state in the opposite direction of decreasing resistance, offsetting the resistance decay caused by the temperature decrease, and achieving adaptive compensation across the entire temperature range.

[0060] The pressure transmitter operates outside its design range of -40°C to 125°C, as follows:

[0061] When the temperature rises to an extreme high temperature of 135℃, a large amount of heat from the pipeline fluid is conducted to the measuring channel 5, causing a sharp increase in the resistance of the strain gauge of the pressure sensor 6, resulting in a signal false high amplitude far exceeding the normal range. Simultaneously, this extreme temperature acts on the thermistor magnetic alloy sheet 802, causing a significant decrease in its permeability, approaching the critical value for magnetic circuit conduction. If the toroidal electromagnet 801 maintains its normal operating magnetic field, the magnetic flux density in the closed magnetic circuit formed by the thermistor magnetic alloy sheet 802 will be too low, resulting in a weak magnetic attraction between the toroidal electromagnet 801 and the thermistor magnetic alloy sheet 802. At this time, the circuit board 17 outputs an adjusted current signal to the toroidal electromagnet 801, appropriately reducing the magnetic field strength of the toroidal electromagnet 801 to avoid residual magnetic attraction leading to overcompensation and ensuring that the magnetic circuit can still form effective magnetic flux. (Miniature elastic...) The support leg 803, utilizing the temperature resistance of its 0.2mm thick permalloy sheet, can still stably elastically extend in its inverted V-shaped structure, pushing the thermistor magnetic alloy sheet 802 downwards. An extremely narrow air gap of 0.2–0.3mm is maintained between the thermistor magnetic alloy sheet 802 and the elastic diaphragm of the pressure sensor 6. The rubber sealing ring 804 maintains its sealing performance at high temperatures, ensuring the sealed isolation between the thermistor magnetic alloy sheet 802 and the pressure sensor 6 during deformation. The thermistor magnetic alloy sheet 802 transmits a compensating force of 0.05–0.1N through the air gap. This thrust acts on the central region of the elastic diaphragm, causing the diaphragm to overcome the elastic resistance at high temperatures and produce a corresponding small deformation downwards. This significantly changes the stress state of the strain gauge, offsetting the sharp increase in resistance caused by extreme high temperatures and maintaining the basic accuracy of the pressure measurement signal.

[0062] When the temperature drops to an extreme low temperature of -50℃, a large amount of heat is lost from the pipeline fluid to the measuring channel 5. The resistance of the strain gauge of the pressure sensor 6 decreases significantly, increasing the risk of false low signal. The extreme low temperature acts on the thermistor magnetic alloy sheet 802, causing a significant increase in the permeability of the thermistor magnetic alloy sheet 802. To maintain the normal working magnetic field, the magnetic flux density in the closed magnetic circuit formed by the thermistor magnetic alloy sheet 802 will be too high. The magnetic attraction of the thermistor 801 to the thermistor magnetic alloy sheet 802 will be too strong, which may cause excessive deformation of the miniature elastic support 803. At this time, the circuit board 17 outputs an adjusted current signal to the thermistor 801 to appropriately increase the magnetic field strength of the thermistor 801, ensuring that the magnetic attraction can both pull the thermistor magnetic alloy sheet 802 to produce effective reverse deformation and avoid damage to the miniature elastic support 803. The magnetic pole design with an upper S pole and a lower N pole, combined with a 0.3-0.5mm magnetic circuit gap between the magnetically conductive alloy sheet 802 and the torsion magnet, ensures a stable increase in magnetic flux density. The magnetic attraction of the toroidal electromagnet 801 to the torsion magnet 802 overcomes the elastic force of the miniature elastic support 803 at low temperatures, causing the torsion magnet 802 to deform in the opposite direction. The rubber sealing ring 804 maintains a sealing and isolation effect at low temperatures. The torsion magnet 802 applies a reverse pulling force of 0.03-0.08N to the elastic diaphragm of the pressure sensor 6 through the air gap. This pulling force acts on the central area of ​​the elastic diaphragm, causing the elastic diaphragm to undergo a slight upward deformation at low temperatures. This causes the strain gauge to adjust its stress state in the opposite direction to increase its resistance, offsetting the significant resistance attenuation caused by extreme low temperatures. This achieves adaptive compensation in extreme low-temperature environments, ensuring the basic measurement function of the pressure transmitter.

[0063] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A high-precision, anti-interference pressure transmitter, comprising: The transmitter housing and a transmitter front cover disposed at the front end of the transmitter housing, wherein a transmitter rear cover is disposed at the rear end of the transmitter housing, characterized in that it further comprises: A locking ring is fixed to the bottom of the transmitter housing; a measurement channel is opened inside the locking ring; a pressure sensor is fixed inside the measurement channel; a sensor base is fixed inside the measurement channel and located directly above the pressure sensor; a temperature compensation component is fixed inside the measurement channel and located between the pressure sensor and the sensor base; and a correction component is fixed inside the measurement channel and located above the sensor base. A ring electromagnet is fixed inside the measurement channel and located directly below the sensor base; a thermistor magnetic alloy sheet is fixed inside the measurement channel and located directly below the ring electromagnet; a miniature elastic support is fixed between the ring electromagnet and the thermistor magnetic alloy sheet; a rubber sealing ring is fixed above the thermistor magnetic alloy sheet and below the pressure sensor. The correction groove is located above the sensor base; the cylindrical electromagnet is fixed inside the measurement channel; the elastic U-shaped piece is fixed on one side of the sensor base and on the cylindrical electromagnet at the other end; the slot is located on the elastic U-shaped piece and fits onto the cylindrical electromagnet; the permanent magnet is fixed on the side of the elastic U-shaped piece closest to the sensor base. An elastic retaining ring is fixed inside the transmitter front cover; a window is fixed inside the elastic retaining ring; two first O-rings are provided, with the two first O-rings respectively fitted onto the transmitter front cover and the transmitter rear cover; a second O-ring is fitted onto the locking ring; an explosion-proof junction box is fixed above the transmitter housing; explosion-proof plugs are fixed at both ends of the explosion-proof junction box; a third O-ring is fitted onto the explosion-proof plugs and is located between the explosion-proof junction box and the explosion-proof plugs; The circuit board is fixed inside the transmitter housing; the circuit panel is fixed inside the transmitter housing and located on one side of the transmitter front cover; the wiring terminals are fixed to the circuit board; the connecting wire is fixed at one end to the circuit board and at the other end to the pressure sensor; the flame-retardant epoxy resin is fixed inside the sensor base and to the connecting wire.

2. The high-precision anti-interference pressure transmitter according to claim 1, characterized in that, Also includes: The set screw is threaded into the bottom of the transmitter housing, with the screw end extending to the outside of the locking ring; Grounding terminal, fixed inside the explosion-proof junction box; plate-shaped nameplate, fixed above the explosion-proof junction box; pan head screw, threaded end passing through the plate-shaped nameplate and screwed into the explosion-proof junction box; curved nameplate, fixed below the transmitter housing.

3. A high-precision anti-interference pressure transmitter according to claim 1, characterized in that, The positioning distance between the sensor base and the annular electromagnet is 1 mm, the magnetic circuit gap between the annular electromagnet and the thermistor magnetically conductive alloy sheet is 0.3-0.5 mm, and the air gap between the thermistor magnetically conductive alloy sheet and the elastic diaphragm of the pressure sensor is 0.2-0.3 mm.

4. A high-precision anti-interference pressure transmitter according to claim 1, characterized in that, The magnetic pole above the annular electromagnet is the S pole, and the magnetic pole below the annular electromagnet is the N pole.

5. A high-precision anti-interference pressure transmitter according to claim 1, characterized in that, The thermistor magnetically conductive alloy sheet is made of Ni45 alloy, and the elastic diaphragm compensation force transmitted from the thermistor magnetically conductive alloy sheet to the pressure sensor is 0.01 to 0.1 N.

6. A high-precision anti-interference pressure transmitter according to claim 1, characterized in that, The micro elastic support is provided in three parts, and the three micro elastic supports are distributed at equal angles around the annular electromagnet as the axis.

7. A high-precision anti-interference pressure transmitter according to claim 1, characterized in that, The miniature elastic support is a 0.2mm thick permalloy sheet, arranged in an inverted V shape.

8. A high-precision anti-interference pressure transmitter according to claim 7, characterized in that, The miniature elastic support leg is 0.5 mm in length and has an elastic coefficient calibrated to 1–2 N / mm.

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