A large-amplitude contact type water level gauge detection calibration device

Abstract

The application discloses a large-amplitude contact type water level gauge detection and calibration device, and belongs to the technical field of water level detection. The device comprises a standard water level gauge system, which is used for obtaining a standard water level value in a detection well; a water level adjusting system, which is used for adjusting the water level in the detection well according to a target water level and a water level change rate; and a data acquisition control system, which comprises a programmable logic controller and is connected with the standard water level gauge system, the water level adjusting system and a detected water level gauge respectively, is used for acquiring data of the water level adjusting system, controlling the water level adjusting system to work through proportional-integral-derivative operation, and controlling an electromagnetic valve and a variable frequency pump to be synchronously opened and closed, and is used for acquiring data of the standard water level gauge system and the detected water level gauge in the detection well, comparing a measurement value acquired by the detected water level gauge with a standard water level value acquired by the standard water level gauge system, and completing water level gauge detection and calibration. The device can realize automatic detection and calibration of the large-amplitude contact type water level gauge based on accurate water level control.

Description

Technical Field

[0001] This invention relates to a large-amplitude contact water level gauge detection and calibration device, belonging to the field of water level detection technology. Background Technology

[0002] Water level is one of the most fundamental monitoring elements in hydrological monitoring. Float-type and pressure-type water level gauges are the most commonly used contact-type water level gauges. They are technologically mature, have high measurement accuracy, are easy to install, low in cost, and easy to maintain, and are therefore widely used in the field of hydrological monitoring.

[0003] Contact level gauge testing and calibration devices are typically built in a testing well. By observing the rise and fall of the water level in the testing well, the measured value of the level gauge is compared with the standard value measured by the testing and calibration device, thereby accurately evaluating the metrological performance of the contact level gauge.

[0004] Due to the limitations of deep wells and the difficulty of accurately controlling the water level inside the well, the measurement range of most contact-type water level gauge testing and calibration devices is currently limited to 10m. They also suffer from problems such as low automation, low efficiency, and poor stability, making it difficult to meet the metrological requirements of high-amplitude, high-precision water level gauges in fields such as high dams and reservoirs, deep-sea observation, and urban deep drainage, which seriously restricts the development of hydrological metrology work. Summary of the Invention

[0005] The purpose of this invention is to provide a large-amplitude contact water level gauge detection and calibration device, which can realize automated detection and calibration of water level with precise control within a large range, and improve the accuracy, efficiency and stability of water level gauge detection and calibration.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a large-amplitude contact level gauge detection and calibration device, comprising: A standard water level gauge system is used to obtain standard water level values ​​in monitoring wells; The water level regulation system is used to regulate the water level in the detection well according to the target water level and the rate of water level change. It includes a water tank, which is connected to the detection well through water injection pipeline and water drainage pipeline. The water injection pipeline is equipped with a variable frequency pump, an electromagnetic flow meter, an electric regulating valve and a solenoid valve in sequence along the water flow direction. The water drainage pipeline is equipped with a variable frequency pump, a one-way shut-off valve and an electromagnetic flow meter in sequence along the water flow direction. The solenoid valve opens and closes synchronously with the variable frequency pump. The data acquisition and control system includes a programmable logic controller (PLC), which is connected to the standard water level gauge system, the water level regulation system, and the water level gauge under test. The PLC is used to acquire data from the water level regulation system and control the operation of the water level regulation system through proportional-integral-derivative operations based on the data. The PLC is also used to acquire data from the standard water level gauge system and the water level gauge under test in the test well, and compare the measured values ​​acquired by the water level gauge under test with the standard water level value acquired by the standard water level gauge system to complete the water level gauge testing and calibration.

[0007] Furthermore, it also includes: The human-machine interaction system, including a touch screen and embedded configuration software, is connected to a programmable logic controller to receive user commands and decompose the detection process. It provides a panoramic operation monitoring mode, and the monitoring interface adopts a multi-view mode, integrating water level curves, equipment status lists, and data tables.

[0008] Furthermore, it also includes: The flexible installation frame, located in the inspection well, includes hoisting steel cables and lifting counterweights. The hoisting steel cables are evenly arranged around the lifting counterweights to form a regular triangular prism spatial structure. The cables, pipelines, and equipment in the inspection well are all fixed to the hoisting steel cables and arranged against the well wall.

[0009] Furthermore, the standard water level gauge system includes a standard water level gauge, which is optically coupled to a water surface reflective float via an optical path steering unit. The standard water level gauge and the optical path steering unit are fixed by a mounting bracket.

[0010] Furthermore, the back of the optical path steering unit is equipped with a multi-dimensional adjustment frame for vertically incident laser light into the detection well and irradiating the water surface reflective float.

[0011] Furthermore, the water surface reflective float moves along the float's movement track, which is a double-track limiting structure. The bottom of the water surface reflective float is equipped with an adjustable counterweight to maintain a stable posture when the water level changes or the water surface fluctuates.

[0012] Furthermore, the water level regulation system adopts a closed-loop circulation structure of ground water tank-dual pump-dual pipeline. The entire water circuit is sealed and pressure-maintained, and is filled with water throughout, so that the actions of the frequency converter pump, electric regulating valve, solenoid valve and one-way shut-off valve are transmitted to the water surface through a continuous water column without delay.

[0013] Furthermore, the end of the water injection pipeline is equipped with a perforated pipe-type dispersed water outlet structure to reduce the impact of the injected water flow on the water surface.

[0014] Furthermore, the programmable logic controller is connected to the frequency converter, and the frequency converter is connected to the frequency pump to adjust the operating speed of the frequency pump. When the water injection pipeline is working, the programmable logic controller controls the electric regulating valve and frequency converter through proportional-integral-derivative operations based on the target water level and the rate of water level change, thereby regulating the flow rate of the water injection pipeline. When the drainage pipeline is in operation, the programmable logic controller controls the frequency converter through proportional-integral-derivative operations based on the target water level and the rate of water level change, thereby adjusting the flow rate of the drainage pipeline. The frequency converter is equipped with an optimized ramp-up time for adjusting the flow rate of the water inlet or outlet pipeline to a finely tuned flow rate as it approaches the target water level.

[0015] Furthermore, the data acquisition and control system also includes a signal conversion unit, which integrates an analog input interface, an SSI absolute encoder interface, and an RS485 interface, used to convert various signals into digital signals that conform to the Modbus-RTU protocol.

[0016] Compared with the prior art, the beneficial effects of the present invention are: The large-amplitude contact level gauge testing and calibration device provided by this invention, through the cooperation of a standard level gauge system, a level regulation system, and a data acquisition and control system, achieves precise and stable regulation of the water level in the testing well. The measurement range covers 0m to 30m, with a measurement accuracy of -3mm to 3mm, supporting a stable water level change rate of 0.2m / min to 0.8m / min, filling the technological gap in large-amplitude contact level gauge testing and calibration devices in the water conservancy industry. The human-machine interface system can receive user commands and break down the testing process, providing a panoramic operation monitoring mode. It integrates water level curves, equipment status lists, and data tables, enabling fully automated guided testing, reducing human intervention during the testing process, and improving testing efficiency and the reliability of test results. The testing well utilizes a convenient and flexible installation frame, enabling the installation and fixation of pipelines, cables, and equipment within the well. This does not occupy testing space and is easy to remove, allowing for installation and subsequent maintenance without personnel entering the well, solving the problems of construction and maintenance in narrow, deep wells. The surface-reflecting float employs a double-track limiting structure for its movement, and its bottom is equipped with an adjustable counterweight, enhancing its stability during water level changes and surface fluctuations in the monitoring well. The water level regulation system utilizes a closed-loop circulation system and a sealed, pressure-maintaining full-pipe design. By controlling the synchronous opening and closing of solenoid valves and variable frequency pumps, and by incorporating one-way shut-off valves, instantaneous flow interruption is achieved, resolving the inertial overshoot and response lag issues associated with water level regulation under conditions of large amplitude variations and long pipelines. The data acquisition and control system integrates analog input interfaces, SSI absolute encoder interfaces, and RS485 interfaces to uniformly convert various signals into digital signals conforming to the Modbus-RTU protocol, achieving unified multi-signal conversion and improving the device's compatibility. Attached Figure Description

[0017] Figure 1This is a schematic diagram of the structure of the large amplitude contact water level gauge detection and calibration device provided in an embodiment of the present invention; In the diagram: 1. Touch screen; 2. Frequency converter; 3. Programmable logic controller; 4. Standard water level gauge; 5. Mounting bracket; 6. Hoisting cable; 7. Water surface reflective float; 8. Float movement track; 9. Detection well; 10. Lifting counterweight; 11. Optical path steering unit; 12. First water level gauge under test; 13. Second water level gauge under test; 14. Water injection pipeline; 15. Drainage pipeline; 16. First solenoid valve; 17. One-way shut-off valve; 18. Spread-tube type dispersed water outlet structure; 19. First frequency converter pump; 20. Second solenoid valve; 21. Electric regulating valve; 22. First electromagnetic flow meter; 23. Second electromagnetic flow meter; 24. Second frequency converter pump; 25. Water tank; 26. Connecting bus; 27. Signal conversion unit. Detailed Implementation

[0018] The technical solution of the present invention will be further described in detail below with reference to specific embodiments.

[0019] Embodiments of the present invention are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Unless otherwise specified, embodiments of the present invention and the technical features thereof can be combined with each other.

[0020] This invention provides a large-amplitude contact level gauge detection and calibration device, comprising: A standard water level gauge system is used to obtain standard water level values ​​in monitoring wells; The water level regulation system is used to regulate the water level in the detection well according to the target water level and the rate of water level change. It includes a water tank, which is connected to the detection well through water injection pipeline and water drainage pipeline. The water injection pipeline is equipped with a variable frequency pump, an electromagnetic flow meter, an electric regulating valve and a solenoid valve in sequence along the water flow direction. The water drainage pipeline is equipped with a variable frequency pump, a one-way shut-off valve and an electromagnetic flow meter in sequence along the water flow direction. The solenoid valve opens and closes synchronously with the variable frequency pump. The data acquisition and control system includes a programmable logic controller (PLC), which is connected to the standard water level gauge system, the water level regulation system, and the water level gauge under test. The PLC is used to acquire data from the water level regulation system and control the operation of the water level regulation system through proportional-integral-derivative operations based on the data. The PLC is also used to acquire data from the standard water level gauge system and the water level gauge under test in the test well, and compare the measured values ​​acquired by the water level gauge under test with the standard water level value acquired by the standard water level gauge system to complete the water level gauge testing and calibration.

[0021] The large-amplitude contact water level gauge testing and calibration device provided in this embodiment of the invention has a measurement range of 0m to 30m, a measurement accuracy of -3mm to 3mm, and supports water level rise and fall rates of 0.2m / min to 0.8m / min. It can realize the testing and calibration of large-amplitude, high-precision contact water level gauges, and ensure the accuracy and reliability of water level detection data of contact water level gauges.

[0022] In one possible embodiment, such as Figure 1 As shown, the large-amplitude contact level gauge testing and calibration device specifically includes: A standard water level gauge system is used to obtain the standard value of water level in the detection well, including a standard water level gauge 4, which is optically coupled to a water surface reflective float 7 through an optical path steering unit 11; The water level regulation system is used to regulate the water level in the detection well according to the target water level and the rate of water level change. It includes a water tank 25, which is connected to the detection well 9 through a water injection pipeline 14 and a drainage pipeline 15. The water injection pipeline 14 is equipped with a second variable frequency pump 24, a first electromagnetic flowmeter 22, an electric regulating valve 21, a second solenoid valve 20, and a first solenoid valve 16 in sequence along the water flow direction. The drainage pipeline 15 is equipped with a first variable frequency pump 19, a one-way shut-off valve 17, and a second electromagnetic flowmeter 23 in sequence along the water flow direction. The first solenoid valve 16 and the second solenoid valve 20 open and close synchronously with the second variable frequency pump 24 to cut off the water flow instantaneously and minimize the effects of water in the pipe and inertia. The data acquisition and control system includes a programmable logic controller (PLC) 3, which is connected to a frequency converter 2, a standard water level gauge 4, a first tested water level gauge 12, a second tested water level gauge 13, a first variable frequency pump 19, a second variable frequency pump 24, a first electromagnetic flowmeter 22, a second electromagnetic flowmeter 23, an electric regulating valve 21, a first solenoid valve 16, and a second solenoid valve 20. The PLC is used to acquire data from the standard water level gauge 4, the first tested water level gauge 12, the second tested water level gauge 13, the first electromagnetic flowmeter 22, and the second electromagnetic flowmeter 23. It is also used to control the electric regulating valve 21 and the frequency converter 2, based on the target water level and the rate of water level change, to adjust the water injection pipeline 14 or the drainage pipeline. The flow rate of 15 is used to regulate the water level in the detection well 9 and to control the first solenoid valve 16 and the second solenoid valve 20 to open and close synchronously with the second variable frequency pump 24; it is also used to compare the measured values ​​obtained by the first tested water level gauge 12 and the second tested water level gauge 13 with the water level standard value obtained by the standard water level gauge 4 to evaluate the metering performance of the first tested water level gauge 12 and the second tested water level gauge 13 and complete the detection and calibration of the first tested water level gauge 12 and the second tested water level gauge 13; and it is used for communication scheduling to coordinate the data exchange between each sensor and actuator; the frequency converter 2 is connected to the first variable frequency pump 19 and the second variable frequency pump 24 respectively, and is used to adjust the operating frequency of the first variable frequency pump 19 or the second variable frequency pump 24.

[0023] Specifically, when the water injection pipeline 14 is working, the programmable logic controller (PLC) controls the electric regulating valve 21 and the frequency converter 2 through proportional-integral-derivative operations based on the target water level and the rate of water level change. The frequency converter 2 adjusts the operating frequency of the second variable frequency pump 24 to regulate the flow rate of the water injection pipeline 14. When the drainage pipeline 15 is working, the PLC controls the frequency converter 2 through proportional-integral-derivative operations based on the target water level and the rate of water level change. The frequency converter 2 adjusts the operating frequency of the first variable frequency pump 19 to regulate the flow rate of the drainage pipeline 15, thereby regulating the water level in the detection well 9.

[0024] In this embodiment, the standard water level gauge 4 is horizontally installed at the wellhead of the detection well 9, which can effectively save the installation space at the wellhead.

[0025] In one possible embodiment, such as Figure 1 As shown, the large amplitude contact level gauge testing and calibration device also includes: The human-machine interaction system includes a touch screen 1 and embedded configuration software, which is connected to a programmable logic controller 3. It is used to receive user instructions and decompose the detection process into five steps: task definition, parameter setting, pre-inspection confirmation, execution monitoring, and result preview. It provides a panoramic operation monitoring mode. The monitoring interface adopts a multi-view mode and integrates water level curves, equipment status lists, and data tables.

[0026] In one possible embodiment, such as Figure 1 As shown, the large amplitude contact level gauge testing and calibration device also includes: A flexible installation frame is installed in the inspection well 9, including a hoisting steel cable 6 and a lifting counterweight 10. The hoisting steel cable 6 is evenly arranged around the lifting counterweight 10 to form a regular triangular prism spatial structure. The cables, pipelines and equipment in the inspection well 9 are all fixed on the hoisting steel cable 6 and are arranged against the well wall of the inspection well 9. This is used for installation and fixation in the narrow inspection well 9, which is convenient for removal and subsequent maintenance.

[0027] In one possible embodiment, such as Figure 1 As shown, the standard water level gauge 4 and the optical path steering unit 11 are fixed by the mounting bracket 5.

[0028] Specifically, the back of the optical path steering unit 11 is equipped with a multi-dimensional adjustment frame for millimeter-level fine adjustment to ensure that the laser is perpendicularly incident on the detection well 9 and irradiates the water surface reflection float 7.

[0029] The water surface reflective float 7 moves along the float movement track 8, which is a double track limiting structure. The bottom of the water surface reflective float 7 is equipped with an adjustable counterweight to maintain a stable posture when the water level changes or the water surface fluctuates.

[0030] In one possible embodiment, such as Figure 1As shown, the water level regulation system adopts a closed-loop circulation structure of ground water tank-dual pump dual pipeline. The entire water circuit is sealed and pressure-maintained, and is full of water throughout, so that the actions of the first variable frequency pump 19, the second variable frequency pump 24, the electric regulating valve 21, the first solenoid valve 16, the second solenoid valve 20 and the one-way shut-off valve 17 are transmitted to the water surface without delay through a continuous water column.

[0031] Specifically, such as Figure 1 As shown, the end of the water injection pipe 14 is provided with a perforated pipe-type dispersed water outlet structure 18 for reducing the impact of the injected water flow on the water surface.

[0032] In one possible embodiment, the inverter 2 is provided with an optimized ramp-up time for adjusting the flow rate of the water inlet line 14 or the drainage line 15 to a fine-tuned flow rate as it approaches the target water level.

[0033] Specifically, such as Figure 1 As shown, the data acquisition and control system also includes a signal conversion unit 27, which integrates an analog input interface, an SSI absolute encoder interface, and an RS485 interface, used to convert various signals into digital signals that conform to the Modbus-RTU protocol.

[0034] The large-amplitude contact level gauge testing and calibration device provided in this invention mainly consists of four core subsystems: a standard level gauge system, a level regulation system, a data acquisition and control system, and a human-machine interaction system. The standard level gauge system acquires standard water level values; the level regulation system enables precise control of any water level; the data acquisition and control system achieves automatic data acquisition and storage, as well as automated control of the entire device; and the human-machine interaction system provides guided automatic detection functionality. Each subsystem works collaboratively. The main process involves the human-machine interaction system receiving user commands, analyzing the detection type and relevant parameters such as the target water level and rate of change, and using the data acquisition and control system to drive the level regulation system and the standard level gauge system to precisely change the actual water level in the well according to a predetermined pattern. Simultaneously, real-time data acquisition is performed, and a detection data report is generated and stored in the human-machine interaction system.

[0035] like Figure 1 As shown, the standard water level gauge system consists of a standard water level gauge 4, a mounting bracket 5, an optical path steering unit 11, a water surface reflecting float 7, and a float movement track 8. The optical path steering unit 11 enables horizontal installation of the laser sensor, effectively saving installation space at the wellhead of the detection well 9. The reflection angle of the optical path steering unit 11 can be precisely adjusted to the millimeter level via a multi-dimensional adjustment bracket on the back, ensuring the verticality of the laser beam entering the detection well 9. To ensure the reflecting float maintains a stable posture and higher stability during water level changes and surface fluctuations, a dual-track limiting design is adopted, and an adjustable counterweight is provided at the bottom.

[0036] The water level regulation system adopts a closed-loop circulation architecture of ground water tank-dual pump-dual pipeline to achieve zero discharge and recycling of water. To achieve precise water level control under conditions of large fluctuations and long pipelines, the required water level fluctuation rate is converted into a corresponding flow rate value. The water level regulation rate is precisely controlled in real time by the first variable frequency pump 19, the second variable frequency pump 24, the electric regulating valve 21, the first electromagnetic flowmeter 22, and the second electromagnetic flowmeter 23. To solve the problem of inertial overshoot, a first solenoid valve 16 and a second solenoid valve 20 are installed in the water injection pipeline 14, and a one-way shut-off valve 17 is installed in the drainage pipeline 15. The first solenoid valve 16 and the second solenoid valve 20 open and close synchronously with the second variable frequency pump 24. The one-way shut-off valve 17 can only be unidirectionally opened and closed, physically and instantaneously cutting off the water flow, reducing the water in the pipe and the effect of inertia to almost zero. To solve the problem of system response time lag, the entire water circuit is sealed and pressurized during system operation, and is filled with water throughout, ensuring that the action of the actuator can be transmitted to the water level surface through a continuous water column with almost no delay. To achieve stable water level control, a perforated pipe-type dispersed water outlet structure 18 is adopted at the end of the water injection pipeline 14, which effectively reduces the impact of the injected water flow and significantly suppresses water surface fluctuations.

[0037] like Figure 1 As shown, the data acquisition and control system includes a programmable logic controller (PLC) 3, a frequency converter 2, a signal conversion unit 27, and a connection bus 26. The small PLC serves as the main controller, responsible for logic control, proportional-integral-derivative (PID) calculations, communication scheduling, safety interlocking, and data acquisition. The frequency converter 2 precisely adjusts the operating frequencies of the first variable frequency pump 19 and the second variable frequency pump 24, optimizing the ramp-up time of the frequency converter 2. When approaching the target water level, the system adjusts to a finely tuned flow rate with a smaller water level fluctuation, achieving smooth deceleration and precise stopping. Specifically, the PLC uses PID calculations to control the frequency converter 2 to adjust the frequency of the variable frequency pumps, while simultaneously adjusting the electric regulating valve 21 to reduce the flow rate from a large flow rate during rapid adjustment to a small flow rate during slow adjustment. The measured values ​​obtained by the first tested water level gauge 12 and the second tested water level gauge 13 are compared with the standard water level value obtained by the standard water level gauge 4 to evaluate the metrological performance of the first tested water level gauge 12 and the second tested water level gauge 13. The signal conversion unit 27 integrates modules such as an analog input interface, an SSI absolute encoder interface, and a standard RS485 interface, uniformly converting various signals into standard Modbus RTU digital signals for input, achieving standardized signal conversion and greatly improving the versatility of the device.

[0038] The human-machine interface (HMI) system includes a touchscreen and embedded configuration software. The HMI design breaks down the complex automated detection process into five steps: task definition, parameter setting, pre-inspection confirmation, execution monitoring, and result preview. This significantly reduces operational difficulty, achieves fully automated detection, improves detection efficiency, and minimizes the impact of human error on the accuracy of detection results. Simultaneously, the HMI provides a panoramic operational monitoring mode. The monitoring interface adopts a multi-view mode, integrating core content such as water level curves, equipment status lists, and data tables, providing clear process control basis for detection.

[0039] In addition, to address the issue of personnel being unable to enter the confined space of inspection well 9 to install and fix cables, pipes, and related equipment, such as... Figure 1 As shown, this embodiment uses hoisting steel cables 6 to suspend and lift the counterweight block 10 to form a flexible installation frame. Three hoisting steel cables 6 are evenly arranged around the circumference of the cylindrical counterweight block 10, forming a regular triangular prism spatial structure with extremely high stability. Cables, pipes, and related equipment are fixed to the hoisting steel cables 6 and attached to the perimeter of the inspection well 9. This structure not only solves the problem of installing and fixing cables, pipes, and related equipment, but also saves space in the confined area of ​​the well and allows for easy removal for maintenance later.

[0040] This invention provides a method for using the large-amplitude contact level gauge detection and calibration device as described in this embodiment, specifically including the following steps: Step 1: Check whether the water level in the ground water tank and the test well is sufficient, and whether there are any abnormalities in the pipelines; Step 2: Install the standard water level gauge according to the marked position and adjust the optical path steering unit, then connect the standard water level gauge to the signal conversion unit; Step 3: The system performs a power-on self-test to check whether the standard water level gauge, electric regulating valve, solenoid valve, frequency converter pump, and electromagnetic flow meter are working properly; Step 4: Install and fix the water level gauge under test on the mounting bracket, and connect the water level gauge under test to the signal conversion unit; Step 5: Set the detection type, initial zero point, water level change rate, water level amplitude, and target water level parameters on the touch screen, and log in to the corresponding calibration personnel account to start automated detection; Step 6: The water level adjustment system first adjusts the water level in the detection well to the initial zero position, and then the water injection pipeline starts to inject water. According to the set water level fluctuation range, the water level stops once every time it rises to a set height. The data acquisition system collects the standard water level value of the standard water level gauge and the water level measurement value of the water level gauge under test, and compares and records them. When the water level in the detection well rises to the target water level, drainage begins. Similarly, the water level stops once every time it drops to a set height and data is collected, until it drops to the initial position, completing the complete detection process. Specifically, during the water level regulation process, the required water level fluctuation rate is converted into a corresponding flow rate value, and the water level regulation rate is controlled in real time through a variable frequency pump, an electric regulating valve, and an electromagnetic flow meter. When approaching the target water level, the system adjusts to a fine-tuned flow rate with a lower water level fluctuation range to achieve smooth deceleration and precise stopping.

[0041] Step 7: After the test is completed, view the test data on the touch screen and export the data.

[0042] The above are merely 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 technical 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 large-amplitude contact-type water level gauge detection and calibration device, characterized in that, include: A standard water level gauge system is used to obtain standard water level values ​​in monitoring wells; The water level regulation system is used to regulate the water level in the detection well according to the target water level and the rate of water level change. It includes a water tank, which is connected to the detection well through water injection pipeline and water drainage pipeline. The water injection pipeline is equipped with a variable frequency pump, an electromagnetic flow meter, an electric regulating valve and a solenoid valve in sequence along the water flow direction. The water drainage pipeline is equipped with a variable frequency pump, a one-way shut-off valve and an electromagnetic flow meter in sequence along the water flow direction. The solenoid valve opens and closes synchronously with the variable frequency pump. The data acquisition and control system includes a programmable logic controller (PLC), which is connected to the standard water level gauge system, the water level regulation system, and the water level gauge under test. The PLC is used to acquire data from the water level regulation system and control the operation of the water level regulation system through proportional-integral-derivative operations based on the data. The PLC is also used to acquire data from the standard water level gauge system and the water level gauge under test in the test well, and compare the measured values ​​acquired by the water level gauge under test with the standard water level value acquired by the standard water level gauge system to complete the water level gauge testing and calibration.

2. The large amplitude contact level gauge detection and calibration device according to claim 1, characterized in that, Also includes: The human-machine interaction system, including a touch screen and embedded configuration software, is connected to a programmable logic controller to receive user commands and decompose the detection process. It provides a panoramic operation monitoring mode, and the monitoring interface adopts a multi-view mode, integrating water level curves, equipment status lists, and data tables.

3. The large amplitude contact level gauge detection and calibration device according to claim 1, characterized in that, Also includes: The flexible installation frame, located in the inspection well, includes hoisting steel cables and lifting counterweights. The hoisting steel cables are evenly arranged around the lifting counterweights to form a regular triangular prism spatial structure. The cables, pipelines, and equipment in the inspection well are all fixed to the hoisting steel cables and arranged against the well wall.

4. The large amplitude contact level gauge detection and calibration device according to claim 1, characterized in that, The standard water level gauge system includes a standard water level gauge, which is optically coupled to a water surface reflective float via an optical path steering unit. The standard water level gauge and the optical path steering unit are fixed by a mounting bracket.

5. The large amplitude contact level gauge detection and calibration device according to claim 1, characterized in that, The back of the optical path steering unit is equipped with a multi-dimensional adjustment frame for vertically incident laser light into the detection well and irradiating the water surface to reflect the float.

6. The large amplitude contact level gauge detection and calibration device according to claim 1, characterized in that, The water surface reflective float moves along the float's movement track, which is a double-track limiting structure. The bottom of the water surface reflective float is equipped with an adjustable counterweight to maintain a stable posture when the water level changes or the water surface fluctuates.

7. The large amplitude contact level gauge detection and calibration device according to claim 1, characterized in that, The water level regulation system adopts a closed-loop circulation structure of ground water tank-dual pump-dual pipeline. The entire water circuit is sealed and pressure-maintained, and is always full of water, so that the actions of the variable frequency pump, electric regulating valve, solenoid valve and one-way shut-off valve are transmitted to the water surface through a continuous water column without delay.

8. The large amplitude contact level gauge detection and calibration device according to claim 1, characterized in that, The end of the water injection pipeline is equipped with a perforated tube-type dispersed water outlet structure to reduce the impact of the injected water flow on the water surface.

9. The large amplitude contact level gauge detection and calibration device according to claim 1, characterized in that, The programmable logic controller (PLC) is connected to the frequency converter, which in turn is connected to the variable frequency pump to regulate the operating speed of the pump. When the water injection pipeline is working, the programmable logic controller controls the electric regulating valve and frequency converter through proportional-integral-derivative operations based on the target water level and the rate of water level change, thereby regulating the flow rate of the water injection pipeline. When the drainage pipeline is in operation, the programmable logic controller controls the frequency converter through proportional-integral-derivative operations based on the target water level and the rate of water level change, thereby adjusting the flow rate of the drainage pipeline. The frequency converter is equipped with an optimized ramp-up time for adjusting the flow rate of the water inlet or outlet pipeline to a finely tuned flow rate as it approaches the target water level.

10. The large amplitude contact level gauge detection and calibration device according to claim 1, characterized in that, The data acquisition and control system also includes a signal conversion unit, which integrates an analog input interface, an SSI absolute encoder interface, and an RS485 interface, used to convert various signals into digital signals that conform to the Modbus-RTU protocol.

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