A measuring terminal, displacement sensor and liquid level measuring device
By designing glass encapsulation and sintering layers, the stability problem of sliding resistive displacement sensors in high temperature, high pressure, dust and corrosive environments has been solved, enabling stable operation in harsh environments.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NINGBO LIJU POWER TECHNOLOGY CO LTD
- Filing Date
- 2025-05-26
- Publication Date
- 2026-06-19
AI Technical Summary
Sliding resistive displacement sensors are unstable and cannot function properly in high temperature, high pressure, dust, and corrosive environments.
The measuring terminal uses glass encapsulation, which places the positive, negative and measuring electrodes in a through hole through the glass encapsulation method. Combined with the glass sintering layer, it enhances the temperature resistance and sealing performance, forming a fully sealed protection system.
The environmental adaptability of the measuring terminals has been improved, enabling them to operate stably in high-temperature, high-pressure, dusty, and corrosive environments, while enhancing their pressure resistance and dustproof performance.
Smart Images
Figure CN224384649U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of liquid level measurement technology, specifically to a measuring terminal, a displacement sensor, and a liquid level measuring device. Background Technology
[0002] A sliding resistive displacement sensor is a device that converts mechanical displacement into an electrical signal output, and it is widely used in various industrial automation systems. The core of a sliding resistive displacement sensor is a variable resistor, the value of which changes as a slider moves along a resistive track. When the sensor is connected to a steady-state DC power supply, by measuring the voltage change between the slider and the starting terminal, the position of the slider can be accurately reflected, thereby enabling the monitoring of object displacement.
[0003] Due to the materials and processes involved in the manufacturing of sliding resistive displacement sensors (which require stringent manufacturing conditions, including multiple manual coatings and natural air drying), they are often quite fragile. Therefore, sliding resistive displacement sensors have strict requirements for the working environment and cannot operate stably in high-temperature, high-pressure, dusty, or corrosive environments. Utility Model Content
[0004] In view of this, the present invention provides a measuring terminal, a displacement sensor and a liquid level measuring device to solve the problem that sliding resistance displacement sensors are not suitable for operation in high temperature, high pressure, dust and corrosive environments.
[0005] In a first aspect, this utility model provides a measuring terminal, comprising:
[0006] The terminal body has three through holes arranged axially.
[0007] Positive terminal, suitable for connection to the positive terminal of a power source;
[0008] Negative terminal, suitable for connection to the negative terminal of the power supply;
[0009] Measuring poles are used to measure the transmission of signals.
[0010] The positive electrode, the negative electrode, and the measuring electrode are respectively disposed in the three through holes by means of glass encapsulation.
[0011] Beneficial effects: The positive, negative, and measuring electrodes of the measuring terminal are respectively set in three axially formed through holes on the terminal body through glass encapsulation. Due to the high temperature resistance of glass, the measuring terminal is prevented from high-temperature deformation or melting failure. Moreover, the low coefficient of thermal expansion of glass can prevent stress cracking caused by sudden temperature changes. The continuous amorphous network structure formed on the glass surface is chemically inert and effectively blocks the penetration and reaction of complex media such as acids, alkalis, and salts. In addition, the glass encapsulation forms a fully sealed protective system, which can still maintain good sealing performance at high temperatures and has good dustproof effect, enabling the measuring terminal to be used in high-temperature, high-pressure, dusty, and corrosive environments, thus improving the environmental applicability of the measuring terminal.
[0012] In one optional embodiment, the through hole is filled with a glass sintered layer, which is formed on the outer periphery of the positive electrode, the negative electrode, and the measuring electrode; the glass sintered layer extends outward from the through hole and contacts and partially covers the end faces of both ends of the terminal body.
[0013] Beneficial effects: The glass sintered layer extends outward from the through hole and partially covers the end faces of both ends of the terminal body, increasing the contact area between the glass sintered layer and the terminal body and improving the pressure resistance.
[0014] In one optional embodiment, the diameters of the positive electrode, the negative electrode, and the measuring electrode are all 0.1 mm; the outer diameter of the glass sintered layer is 0.2 mm.
[0015] Beneficial effects: If the outer diameter of the glass sintered layer is too large, it will affect the sintering process and cause a decrease in the withstand voltage value. By setting the diameter of the positive electrode, negative electrode and measuring electrode to 0.1 mm and the outer diameter of the glass sintered layer to 0.2 mm, the insulation requirements of the electrodes to ground can be guaranteed, while also ensuring the glass sintering processability and good withstand voltage performance, thus satisfying the balance between the insulation requirements to ground and the high withstand voltage value.
[0016] In one alternative embodiment, all three through holes are chamfered at both ends of the terminal body.
[0017] Beneficial effect: Setting chamfers at both ends of the through hole can increase the contact area between the glass and the measuring terminal during glass sintering, thereby increasing the pressure resistance.
[0018] Secondly, this utility model also provides a displacement sensor, comprising:
[0019] The resistance rail has a measuring side and a measuring opposite side that are opposite to each other;
[0020] A sliding measuring head is slidably mounted on the resistance rail; it is suitable for connection with the object being measured so that the displacement of the object being measured can be reflected by the displacement of the sliding measuring head.
[0021] The measuring terminal according to any one of the above is disposed at the end of the resistance rail, and the positive electrode and the negative electrode are disposed on the measuring side, and the measuring electrode is disposed on the measuring opposite side.
[0022] Beneficial effects: Since the displacement sensor includes the measuring terminal of this invention, it possesses the same technical effects as the measuring terminal, which will not be elaborated here. Furthermore, by moving the sliding measuring head, the voltage corresponding to the resistance at different positions on the measuring side can be transmitted through the sliding measuring head to the guide rail on the opposite side and finally to the signal processing unit through the measuring terminal, thereby realizing the measurement of the displacement of the sliding measuring head. The signal processing unit can directly calculate the corresponding displacement value by comparing the power supply voltage and the measured output voltage.
[0023] In one alternative implementation, the resistor rail includes:
[0024] Matrix;
[0025] A base plate is placed on the substrate, and the base plate is an insulating base plate;
[0026] Gold-plated circuitry is mounted on the base plate;
[0027] An insulating film is applied to a portion of the gold-plated circuitry.
[0028] A thick-film resistor is disposed on a portion of the insulating film and a portion of the gold-plated circuit; the insulating film is adapted to isolate the portion of the gold-plated circuit from the thick-film resistor.
[0029] Beneficial effects: According to the measurement needs, an insulating layer and circuit are printed on the substrate to form a hierarchical structure. The base plate is made of a high-temperature resistant and highly insulating material to ensure the insulation between the circuit and the substrate. The gold-plated circuit serves as the conductor of the entire measurement circuit. The insulating film isolates the thick film resistor from the gold-plated circuit at specific positions, so that the thick film resistor only contacts the gold-plated circuit at the start and end of the measurement, realizing the connection between the positive and negative terminals.
[0030] In one alternative embodiment, on the measurement side, the gold-plated circuit has a break between the negative and positive terminals, and the thick-film resistor covers the substrate at the break and is able to connect the negative and positive terminals to form a complete circuit.
[0031] Beneficial effects: On the measurement side, by setting the coverage position of the gold-plated circuit and the thick film resistor, a complete circuit is formed between the negative and positive terminals during the measurement process, so that voltage changes can be measured at the measurement terminals, thereby monitoring the displacement changes of the sliding measuring head.
[0032] In one alternative embodiment, on the opposite side of the measurement, the gold-plated circuit completely covers the base plate; the insulating film is not disposed on the opposite side of the measurement, and the thick-film resistor covers the gold-plated circuit, so that the end of the sliding measuring head located on the opposite side of the measurement is in contact with the thick-film resistor.
[0033] Beneficial effect: On the opposite side of the measurement, no insulating film is set between the gold-plated circuit and the thick film resistor. The thick film resistor directly covers the gold-plated circuit, so that the sliding measuring head can directly contact the thick film resistor on the opposite side of the measurement and conduct electricity directly.
[0034] In one optional embodiment, the thickness of the thick film resistor is 10 μm to 30 μm.
[0035] Beneficial effects: The thickness of the thick film resistor is 10μm to 30μm, and the vertical resistance value is negligible. This design can also increase the wear resistance of the measurement side.
[0036] Thirdly, this utility model also provides a liquid level measuring device, comprising:
[0037] The shell forms a cavity containing liquid;
[0038] The displacement sensor described in any of the above embodiments is inserted through the housing and located within the receiving cavity; the sliding measuring head is adapted to move up and down as a float moves with the liquid surface of the liquid.
[0039] Beneficial effects: Since the liquid level measuring device includes the displacement sensor of this utility model and the measuring terminals are encapsulated in glass, it can be applied to liquid level measurement in harsh environments such as high temperature, high pressure, dust and corrosion, thus improving the measurement stability and reliability. Attached Figure Description
[0040] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of this utility model, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0041] Figure 1 This is a perspective view of a measuring terminal according to an embodiment of the present utility model;
[0042] Figure 2 This is a front view of a measuring terminal according to an embodiment of the present utility model;
[0043] Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure of AA;
[0044] Figure 4 This is a top view of a measuring terminal according to an embodiment of the present utility model;
[0045] Figure 5 This is a three-dimensional structural schematic diagram of a displacement sensor according to an embodiment of the present utility model;
[0046] Figure 6 This is a front view of a displacement sensor according to an embodiment of the present invention;
[0047] Figure 7 This is a schematic diagram of the displacement sensor of this utility model when it is installed in a harsh environment;
[0048] Figure 8 This is a schematic diagram of the layered structure of the resistor rail according to an embodiment of the present invention;
[0049] Figure 9 This is a schematic diagram of the layered structure and current flow state of the measuring side and the measuring opposite side in an embodiment of the present invention.
[0050] Figure 10 This is a schematic diagram of the structure of a liquid level measuring device according to an embodiment of the present invention.
[0051] Explanation of reference numerals in the attached figures:
[0052] 1. Measuring terminals;
[0053] 11. Terminal body; 111. Through hole;
[0054] 12. Electrode; 121. Positive electrode; 122. Negative electrode; 123. Measuring electrode;
[0055] 13. Glass sintering layer;
[0056] 2. Resistance rail;
[0057] 21. Measurement side;
[0058] 22. Measure the opposite side;
[0059] 3. Sliding measuring head;
[0060] 100. Displacement sensor;
[0061] 200. Shell. Detailed Implementation
[0062] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0063] In the description of this utility model, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0064] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0065] The following is combined Figures 1 to 10 The following describes embodiments of the present invention.
[0066] According to embodiments of the present invention, on the one hand, such as Figures 1 to 4 As shown, a measuring terminal 1 is provided, including:
[0067] The terminal body 11 has three through holes 111 arranged axially.
[0068] Positive terminal 121, suitable for connection to the positive terminal of a power supply;
[0069] Negative terminal 122 is suitable for connection to the negative terminal of the power supply;
[0070] Measuring pole 123 is used for the transmission of measurement signals;
[0071] The positive electrode 121, the negative electrode 122, and the measuring electrode 123 are respectively disposed in three through holes 111 by means of glass encapsulation.
[0072] The positive electrode 121, negative electrode 122, and measuring electrode 123 of the measuring terminal 1 are respectively disposed in three through holes 111 formed axially on the terminal body 11 by glass encapsulation. Due to the high temperature resistance of glass, the measuring terminal 1 is prevented from deforming or melting at high temperatures. Moreover, the low coefficient of thermal expansion of glass can prevent stress cracking caused by sudden temperature changes. The glass surface forms a continuous amorphous network structure, which is chemically inert and effectively blocks the penetration and reaction of complex media such as acids, alkalis, and salts. In addition, the glass encapsulation forms a fully sealed protective system, which can still maintain good sealing performance at high temperatures and has a good dustproof effect, enabling the measuring terminal 1 to be used in high temperature, high pressure, dusty and corrosive environments, thus improving the environmental applicability of the measuring terminal 1.
[0073] It should be noted that the through hole 111 is filled with a glass sintered layer 13, which is formed on the outer periphery of the positive electrode 121, the negative electrode 122 and the measuring electrode 123.
[0074] Furthermore, in some embodiments, the glass sintered layer 13 extends outward from the through-hole 111 and contacts and partially covers the end faces of both ends of the terminal body 11. By extending the glass sintered layer 13 outward from the through-hole 111 and partially covering the end faces of the terminal body 11, the contact area between the glass sintered layer and the terminal body 11 is increased, thereby improving the pressure resistance.
[0075] In some embodiments, the diameters of the positive electrode 121, the negative electrode 122, and the measuring electrode 123 are all 0.1 mm; the outer diameter of the glass sintered layer 13 is 0.2 mm.
[0076] If the outer diameter of the glass sintered layer 13 is too large, it will affect the sintering process and cause a decrease in the withstand voltage value. The diameters of the electrodes 12, namely the positive electrode 121, the negative electrode 122 and the measuring electrode 123, are set to 0.1 mm, and the outer diameter of the glass sintered layer 13 is set to 0.2 mm. This ensures the insulation requirements of the electrodes 12 to ground while also ensuring the glass sintering processability and good withstand voltage performance, thus achieving a balance between the insulation requirements to ground and the high withstand voltage value.
[0077] In some embodiments, the three through holes 111 are all provided with chamfers at both ends of the terminal body 11.
[0078] Chamfers are provided at both ends of the through hole 111 to increase the contact area between the glass and the measuring terminal 1 during glass sintering, thereby increasing the pressure resistance.
[0079] This utility model provides a measuring terminal 1 that can ensure ultra-high withstand voltage characteristics while transmitting signals. Its core lies in the three through holes 111 designed at the center of the measuring terminal 1, corresponding to the positive electrode 121, negative electrode 122, and measuring electrode 123 of the displacement sensor 100. The positive electrode 121 and negative electrode 122 correspond to the same side of the measuring guide rail, i.e., the measuring side 21; the measuring electrode 123 corresponds to the opposite measuring side 22 of the measuring guide rail. Both the positive electrode 121 and negative electrode 122 are located on the measuring side 21 of the resistance rail 2, as shown below. Figure 10 As shown, the current starts from the power supply module, passes through the signal processing unit, and then reaches the measurement side 21 of the resistance rail 2 via the electrode 12 of the measurement terminal 1. After passing through the thick-film resistor corresponding to the complete measurement distance, it returns to the signal processing unit and the power supply module, forming a closed loop. Throughout the measurement process, the power supply voltage remains constant, and the current in the circuit also remains constant. The sliding measuring head 3 achieves conduction by contacting the thick-film resistor through metal contacts, enabling real-time sensing of voltage changes at different positions on the resistance rail 2. This voltage change is transmitted from the measurement side 21 of the resistance rail 2 to the measurement opposite side 22 of the resistance rail 2 via the sliding measuring head 3. This is because the sliding measuring head 3 is designed to connect the measurement side 21 and the measurement opposite side 22 of the resistance rail 2. The final measured voltage change will be transmitted via the sliding measuring head 3 to the circuit on the opposite side 22 of the resistance rail 2. The circuit on the opposite side 22 of the resistance rail 2 consists of a thick-film resistor printed on a gold-plated circuit. This thick-film resistor ensures continuity between any two points in the circuit, as its thickness is on the micrometer scale. The main function of the thick-film resistor is to improve the circuit's wear resistance. The final voltage signal passes through the conductor on the opposite side 22 to the outside of the high-temperature resistant terminal, ultimately reaching the signal processing unit. The electrodes 12 on the high-temperature resistant measuring terminal 1 are connected to the circuits on both sides of the resistance rail 2 by soldering. Two terminals need to be soldered on the measuring side 21, corresponding to the positive and negative terminals of the power supply, respectively. One terminal needs to be soldered on the opposite side 22, corresponding to the measuring electrode 123 (output electrode), to realize the transmission of the final measured voltage signal, thereby ultimately powering the measuring circuit and transmitting the measurement result signal. The electrode 12 is fixed in the middle of the three through holes 111 by glass encapsulation, which not only ensures the high impedance of the electrode 12, but also achieves good withstand voltage characteristics on both sides of the terminal.
[0080] According to an embodiment of the present invention, on the other hand, as... Figures 5-7 As shown, a displacement sensor 100 is also provided, comprising:
[0081] The resistance rail 2 has a measuring side 21 and a measuring opposite side 22 that are opposite to each other;
[0082] The sliding measuring head 3 is slidably mounted on the resistance rail 2; it is suitable for connection with the object being measured so that the displacement of the object being measured can be reflected by the displacement of the sliding measuring head 3.
[0083] Measurement terminal 1 is located at the end of resistance rail 2, with positive electrode 121 and negative electrode 122 located on measurement side 21 and measurement electrode 123 located on measurement opposite side 22.
[0084] Since the displacement sensor 100 includes the measuring terminal 1 of this invention, it has the same technical effects as the measuring terminal 1, which will not be described in detail here. Furthermore, by moving the sliding measuring head 3, the voltage corresponding to the resistance at different positions on the measuring side 21 can be transmitted through the sliding measuring head 3 to the guide rail on the measuring opposite side 22 and finally to the signal processing unit through the measuring terminal 1, thereby realizing the measurement of the displacement of the sliding measuring head 3. The signal processing unit can directly calculate the corresponding displacement value by comparing the power supply voltage and the measured output voltage.
[0085] In some embodiments, the resistor rail 2 includes:
[0086] Matrix;
[0087] The base plate covers the substrate and is an insulating base plate;
[0088] Gold-plated circuitry is mounted on the base plate.
[0089] An insulating film covers part of the gold-plated circuitry;
[0090] A thick-film resistor is disposed on a portion of an insulating film and a portion of a gold-plated circuit; the insulating film is suitable for isolating the portion of the gold-plated circuit from the thick-film resistor.
[0091] According to the measurement requirements, an insulating layer and circuit are printed on the substrate to form a hierarchical structure. The base plate is made of a high-temperature resistant and highly insulating material to ensure insulation from the substrate. The gold-plated circuit serves as the conductor of the entire measurement circuit. The insulating film isolates the thick film resistor from the gold-plated circuit at specific locations, so that the thick film resistor only contacts the gold-plated circuit at the start and end of the measurement, thus realizing the connection between the positive electrode 121 and the negative electrode 122.
[0092] Specifically, on the measuring side 21, the gold-plated circuit has a break between the negative terminal 122 and the positive terminal 121. A thick film resistor is placed on the base plate at the break and can connect the negative terminal 122 and the positive terminal 121 to form a complete circuit.
[0093] On the measuring side 21, by setting the covering position of the gold-plated circuit and the thick film resistor, a complete circuit is formed between the negative electrode 122 and the positive electrode 121 during the measurement process, so that voltage changes can be measured at the measuring electrode 123, thereby monitoring the displacement changes of the sliding measuring head 3.
[0094] Specifically, on the opposite side 22 of the measurement, the gold-plated circuit completely covers the base plate; the insulating film is not set on the opposite side 22 of the measurement, and the thick film resistor covers the gold-plated circuit, so that the sliding measuring head 3 is in contact with the thick film resistor at one end of the opposite side 22 of the measurement.
[0095] On the opposite side 22, no insulating film is set between the gold-plated circuit and the thick film resistor. The thick film resistor directly covers the gold-plated circuit, so that the sliding measuring head 3 directly contacts the thick film resistor on the opposite side 22 and can conduct electricity directly.
[0096] In some embodiments, the thickness of the thick film resistor is 10 μm to 30 μm.
[0097] The thickness of the thick film resistor is 10μm to 30μm, and the vertical resistance value is negligible. This design can also increase the wear resistance of the opposite side 22.
[0098] like Figure 8 and Figure 9 As shown, in one specific embodiment, the resistor rail 2 is designed in layers, using nickel-plated aluminum as the substrate. High-temperature resistant and highly insulating polyimide base plates are covered on both sides of the substrate, and gold-plated circuits are covered on the polyimide base plates on both sides. The measurement side 21 has a total of four layers, from bottom to top: a polyimide base plate, a gold-plated circuit, a polyimide film as an insulating layer, and a thick-film resistor with a specific resistance value. The polyimide base plate is used to maintain insulation from the rail. The gold-plated circuit serves as the conductor for the entire measurement circuit. The polyimide film is used to isolate the thick-film resistor from the gold-plated circuit at specific locations. The thick-film resistor connects the gold-plated circuits closer to the terminals and those farther from the terminals. On the entire measurement side 21, only at the start and end points of the measurement is the gold-plated circuit located below the thick-film resistor; in other sections, only the insulating film is located below the thick-film resistor, thus achieving the connection between the positive electrode 121 and the negative electrode 122. On the opposite side 22, there is a three-layer structure: from bottom to top, a polyimide base plate, a gold-plated circuit, and a thick-film resistor. The gold-plated circuit completely covers the polyimide base plate, and a thick-film resistor is placed on top of it. This allows the contacts of the sliding measuring head 3 to directly contact the thick-film resistor and conduct electricity directly. Because the thickness of the thick-film resistor is 10μm to 30μm, its vertical resistance is negligible. This design also increases the wear resistance of the opposite side 22. Finally, through the movement of the sliding measuring head 3, the voltage corresponding to the resistance value at different positions on the measuring side 21 can be transmitted to the opposite side 22 of the resistor rail 2 via the sliding measuring head 3, and finally transmitted to the signal processing unit through the measuring terminal 1, thereby realizing the measurement of displacement. The signal processing unit can directly calculate the corresponding displacement by comparing the power supply voltage and the measured output voltage.
[0099] The sliding measuring head 3 is symmetrically designed based on the measuring circuits on both sides of the guide rail. This ensures that the measuring head contacts the measuring circuits on both sides with uniform force, achieving uninterrupted resolution during the movement of the sliding measuring head 3 while also guaranteeing the consistency of the position contact buffer pressure. This reduces wear on the resistive rail by the metal contacts and improves the lifespan of the measuring circuit. It should be noted that the symmetrical design referred to here is approximately symmetrical. Both the measuring side 21 and the opposite measuring side 22 are layered designs, and the opposite measuring side 22 has only one less layer of polyimide film than the measuring side 21. Therefore, the final thickness difference is very small. The symmetrical design means that from the perspective of the entire module, the thickness on both sides is almost the same.
[0100] According to an embodiment of the present invention, in another aspect, such as Figure 10 As shown, a liquid level measuring device is also provided, comprising:
[0101] The shell 200 forms a cavity containing liquid;
[0102] A displacement sensor 100 is installed inside the housing 200 and located within the receiving cavity. A sliding measuring head 3 is adapted to act as a float, rising and falling with the movement of the liquid surface. The sliding measuring head 3 is in direct contact with the measured liquid medium and is used to detect mechanical displacement. By rigidly or flexibly connecting the sliding measuring head 3 to the measuring medium, the actual mechanical displacement of the measured object will be reflected in the axial movement of the sliding measuring head 3 along the resistance rail 2. Changes in the displacement of the sliding measuring head 3 correspond to different changes in resistance, ultimately outputting the result from the high-temperature resistant measuring terminal 1.
[0103] Since the liquid level measuring device includes the displacement sensor 100 of this utility model and the measuring terminal 1 is encapsulated in glass, it can be applied to liquid level measurement in harsh environments such as high temperature, high pressure, dust and corrosion, thus improving the measurement stability and reliability.
[0104] Specifically, the liquid level measuring device also includes:
[0105] The signal processing unit includes modules such as amplifiers and filters. Its main functions include filtering and processing the measurement data from the measurement terminal 1 of the displacement sensor 100, and outputting measurement results that can completely, specifically and realistically reflect the displacement of the sliding measuring head 3.
[0106] The output unit is usually a digital-to-analog converter module, which includes functions such as analog output and digital output. The output is an electrical signal that can be recognized by the control system and can reflect the absolute displacement of the sliding measuring head 3.
[0107] The power supply module provides a stable voltage to the measurement terminal 1, the signal processing unit, and the output unit.
[0108] The displacement sensor 100 of this invention utilizes a high-temperature and high-pressure resistant glass encapsulation technology for its measuring terminal 1, resulting in extremely high pressure resistance for the entire displacement sensor 100. This invention ensures that the electrode 12 is mounted on the terminal body 11 and insulated from ground through glass sintering. The diameter of the electrode 12 in the measuring terminal 1 is determined to be 0.1 mm, and the inner and outer diameters of the sintered glass are 0.1 mm and 0.2 mm, respectively. Chamfers are designed at the holes in the sintered glass, and during glass sintering, material overflows from the openings of the through holes 111 at both ends, increasing the pressure resistance of the interface. This is because adding chamfers increases the contact area between the glass and the measuring terminal 1. Under the same pressure, a larger area results in a smaller pressure at a single point, allowing that point to withstand higher pressure values.
[0109] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by this application.
Claims
1. A measuring terminal, characterized by include: The terminal body (11) has three through holes (111) arranged axially. Positive terminal (121), suitable for connection to the positive terminal of a power source; Negative terminal (122), suitable for connection to the negative terminal of the power supply; The measuring pole (123) is used for the transmission of measurement signals; The positive electrode (121), the negative electrode (122), and the measuring electrode (123) are respectively disposed in the three through holes (111) by means of glass encapsulation.
2. The measuring terminal according to claim 1, characterized in that The through hole (111) is filled with a glass sintered layer (13), which is formed on the outer periphery of the positive electrode (121), the negative electrode (122) and the measuring electrode (123). The glass sintered layer (13) extends outward from the through hole (111) and contacts and partially covers the end faces of both ends of the terminal body (11).
3. The measuring terminal according to claim 2, characterized in that The diameters of the positive electrode (121), the negative electrode (122), and the measuring electrode (123) are all 0.1 mm; the outer diameter of the glass sintered layer (13) is 0.2 mm.
4. The measurement terminal of claim 1, wherein The three through holes (111) are all chamfered at both ends of the terminal body (11).
5. A displacement sensor, characterized by, include: The resistance rail (2) has a measuring side (21) and a measuring opposite side (22) that are opposite to each other; A sliding measuring head (3) is slidably mounted on the resistance rail (2); it is suitable for connection with the object being measured so that the displacement of the object being measured can be reflected by the displacement of the sliding measuring head (3); According to any one of claims 1 to 4, the measuring terminal (1) is disposed at the end of the resistance rail (2), and the positive electrode (121) and the negative electrode (122) are disposed on the measuring side (21), and the measuring electrode (123) is disposed on the measuring opposite side (22).
6. The displacement sensor of claim 5, wherein, The resistance rail (2) includes: Matrix; A base plate is placed on the substrate, and the base plate is an insulating base plate; Gold-plated circuitry is mounted on the base plate; An insulating film is applied to a portion of the gold-plated circuitry. A thick-film resistor is disposed on a portion of the insulating film and a portion of the gold-plated circuit; the insulating film is adapted to isolate the portion of the gold-plated circuit from the thick-film resistor.
7. The displacement sensor of claim 6, wherein, On the measuring side (21), the gold-plated circuit has a break between the negative electrode (122) and the positive electrode (121). The thick film resistor covers the substrate at the break and can connect the negative electrode (122) and the positive electrode (121) to form a complete circuit.
8. The displacement sensor of claim 7, wherein, On the opposite side of the measurement (22), the gold-plated circuit completely covers the base plate; the insulating film is not set on the opposite side of the measurement (22), and the thick film resistor covers the gold-plated circuit, so that the sliding measuring head (3) is in contact with the thick film resistor at one end of the opposite side of the measurement (22).
9. The displacement sensor of claim 6, wherein, The thickness of the thick film resistor is 10μm to 30μm.
10. A liquid level measuring device, characterized in that, include: The shell (200) forms a cavity containing liquid; The displacement sensor (100) according to any one of claims 5 to 9 is disposed in the housing (200) and located in the receiving cavity; the sliding measuring head (3) is adapted to move up and down as a float with the movement of the liquid surface.