Intelligent combined measurement method for groundwater

Abstract

The present application relates to the technical field of intelligent sensor measurement, in particular to a kind of intelligent groundwater combined measurement method.The specific implementation process includes: detecting and filtering current atmospheric pressure, setting pressure zeroization reference;Utilize the scale pressure cooperative measurement to generate liquid level scale value, and compensate and correct by fusing hydrostatic pressure value, output dynamic liquid level depth;Utilize the bottoming pressure measurement to identify bottoming event, and lock the maximum hydrostatic pressure value to convert total liquid column height;Total depth value is calculated by combining liquid level scale value and total liquid column height, integrated as combined measurement data;When liquid level occurs overrun fluctuation, automatically trigger alarm.The present application combines high-precision scale positioning, dynamic pressure sensing and intelligent judgment, effectively improves the problem of single dimension, easy to be disturbed by environment and unable to obtain well depth full parameter in sensor measurement process, significantly improves the integration and accuracy of sensor measurement.

Description

Technical Field

[0001] This invention relates to the field of intelligent sensor measurement technology, specifically to an intelligent groundwater joint measurement method. Background Technology

[0002] In the field of liquid level measurement technology, the determination of the liquid level or flowable solid material in a container (i.e., a groundwater monitoring well) mainly relies on fixed automated sensors, including water temperature sensors, ultrasonic sensors, radar level gauges, and hydrostatic level sensors. By transmitting and receiving reflected signals to the liquid surface, the pressure generated by the liquid column is sensed and converted into an electrical signal, thereby enabling unattended and continuous data recording of the liquid level.

[0003] However, existing technologies have shortcomings in practical liquid level measurement. While fixed automated sensors improve objectivity and automation, their inherent installation method limits their application flexibility, making them unsuitable for portable inspections of multiple containers. Due to their fixed sensor positions, their measurement dimensions are also incomplete; for example, top-mounted sensors cannot determine the total depth, and bottom-mounted sensors cannot directly measure the liquid level, thus failing to provide complete spatial dimensional information about the liquid within the container. This results in a contradiction between functional integration, measurement dimensional completeness, objective accuracy, and operational flexibility, making it difficult to efficiently combine multi-parameter precise measurement with portable application scenarios.

[0004] To address this, an intelligent joint groundwater measurement method is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide an intelligent groundwater joint measurement method to achieve intelligent joint measurement of multiple groundwater parameters.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A smart groundwater joint measurement method includes: After the water level gauge is started, it automatically detects the current atmospheric pressure, sets and stores the atmospheric pressure as the pressure zeroing reference. The water level gauge is lowered into the container to be measured. When it first contacts the liquid surface, a liquid level scale value is generated through gauge pressure co-measurement. The hydrostatic pressure value below the liquid surface is measured and output in real time based on the pressure zeroing benchmark. The liquid level scale value and the hydrostatic pressure value are fused based on hydrostatic compensation, and measurement correction is performed to output the dynamic liquid level depth. When the water level gauge touches the bottom of the container to be measured, the bottoming event is marked by the final pressure measurement at the bottom; the maximum value of the hydrostatic pressure during the entire descent is locked and output as the total liquid column height; the total depth value is obtained by combining the liquid level scale value and the total liquid column height, and all liquid information is integrated into joint measurement data; During the descent process, the liquid level change of the dynamic liquid level depth is continuously calculated; when the liquid level change exceeds the liquid level fluctuation threshold, the liquid level over-limit alarm is automatically triggered.

[0007] Preferably, the specific implementation process of automatically detecting the current atmospheric pressure after the water level gauge is started, setting and storing the atmospheric pressure as the pressure zeroing reference includes: The pressure sensor built into the water level gauge collects and records the air pressure data of the current environment and uses it as the raw atmospheric pressure sample. The raw atmospheric pressure sample is filtered to remove abnormal pressure readings caused by environmental airflow disturbances. The average atmospheric pressure is calculated and stored as the pressure zeroing reference.

[0008] Preferably, the specific implementation process of lowering the water level gauge into the container to be measured, and generating a liquid level scale value through gauge pressure-assisted measurement upon initial contact with the liquid surface, includes: The moment the electrode sensor of the water level gauge comes into contact with the liquid surface, a closed loop is formed due to the conductivity of the liquid, triggering a liquid surface contact signal. The water level gauge receives the liquid surface contact signal and starts the ruler-pressure collaborative measurement, immediately locking the real-time release length of the synchronously descending scale steel ruler and outputting the liquid level scale value. The ruler-pressure collaborative measurement constructs a multi-source data fusion processing framework and performs structural compensation according to the initial absolute depth benchmark.

[0009] Preferably, the specific implementation process of measuring and outputting the hydrostatic pressure value below the liquid level in real time based on the pressure zeroing reference includes: After the water level gauge descends and enters below the liquid surface, the built-in pressure sensor continuously collects the current absolute pressure value, forming a mixed pressure data stream containing atmospheric pressure and hydrostatic pressure. Differential operation is performed on each pressure sample value in the mixed pressure data stream to remove the atmospheric pressure component represented by the pressure zeroing reference, constructing a pure hydrostatic pressure data sequence. After the pure hydrostatic pressure data sequence is formatted, the hydrostatic pressure value is output.

[0010] Preferably, the specific implementation process of merging the liquid level scale value and the fluid static pressure value based on static pressure compensation, and performing measurement correction to output the dynamic liquid level depth includes: Based on liquid density and gravitational acceleration, the hydrostatic pressure value of the fluid is continuously calculated into depth increment data through a pressure-depth conversion processor; the depth increment data is superimposed on the liquid level scale value to generate a preliminary dynamic depth sequence; the water temperature data of the water level gauge's built-in temperature sensor is called, and the buoyancy change of the scale steel ruler at different immersion depths is calculated to measure and correct the preliminary dynamic depth sequence, and the dynamic liquid level depth is output.

[0011] Preferably, when the water level gauge contacts the bottom of the container to be measured, the specific implementation process of using the final pressure measurement at the bottom to indicate the bottom contact event includes: During the descent of the water level gauge, the gradient of the hydrostatic pressure value within the sliding time window is continuously calculated; the final pressure measurement at the bottom is performed according to the pressure stability judgment criterion to distinguish whether the gradient of the hydrostatic pressure value belongs to the normal descent state or the bottoming state; when the gradient of the hydrostatic pressure value is identified as the bottoming state, a bottoming event identifier is immediately generated.

[0012] Preferably, the specific implementation process of locking the maximum value of the hydrostatic pressure during the entire descent process and outputting it as the total liquid column height includes: After the water level gauge is immersed in the liquid surface, the maximum pressure recording value is initialized, and each new hydrostatic pressure value is compared with the currently stored maximum pressure recording value, and the maximum pressure recording value is continuously updated; when the bottoming event flag is received, the hydrostatic pressure value is stopped and the maximum pressure recording value is locked; the maximum pressure recording value is transmitted to the physical quantity conversion sensor, and the total liquid column height is calculated and output according to the fluid physical parameters.

[0013] Preferably, the specific implementation process of obtaining the total depth value by combining the liquid level scale value and the total liquid column height, and integrating all liquid information into joint measurement data includes: The liquid level scale value recorded during the measurement process is retrieved, and the liquid level scale value is arithmetically superimposed with the total liquid column height to calculate the total depth value representing the distance from the measurement reference point to the bottom of the container. The liquid level scale value, dynamic liquid level depth, total liquid column height, and total depth value are integrated and packaged into joint measurement data containing multiple liquid physical dimension information.

[0014] Preferably, the specific implementation process for continuously calculating the liquid level change of the dynamic liquid level depth includes: The continuously output dynamic liquid level depth is sent to the data buffer sensor in real time and temporarily stored as a historical depth data sequence; the latest dynamic liquid level depth is extracted in each calculation cycle, and the historical depth value corresponding to the previous calculation cycle is retrieved from the data buffer sensor; a difference operation is performed on the dynamic liquid level depth and the historical depth value to generate the liquid level change amount representing the direction of liquid level rise and fall.

[0015] Preferably, the specific implementation process for automatically triggering a liquid level over-limit alarm when the liquid level change exceeds the liquid level fluctuation threshold includes: The liquid level change is input to the early warning judgment sensor and compared with the liquid level fluctuation threshold. When the absolute value of the liquid level change exceeds the liquid level fluctuation threshold, an over-limit alarm signal is immediately generated. The over-limit alarm signal is sent to the human-machine interface to provide audible and visual alarms for abnormal liquid level fluctuations.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention integrates multiple measurement methods into one intelligent sensor, which can simultaneously acquire multiple key parameters such as dynamic liquid level depth, total liquid column height, and total depth, providing complete spatial dimensional information about the liquid inside the container, thus improving the balance between the functional integration of the water level gauge and the completeness of the measurement dimensions.

[0017] 2. This invention reduces the influence of environmental factors on groundwater measurement results. It combines two measurement methods, namely, pressure measurement and bottom pressure measurement, to jointly measure groundwater, correcting measurement errors caused by changes in water temperature and buoyancy, and effectively improving the accuracy of groundwater measurement results.

[0018] 3. The multifunctional water level gauge proposed in this invention can perform inspections between multiple different containers, greatly improving the flexibility of application. It is not only suitable for fixed groundwater monitoring wells, but can also be widely used in portable application scenarios that require liquid level measurement in multiple containers. Attached Figure Description

[0019] Figure 1 This is a flowchart of an intelligent groundwater joint measurement method proposed in this invention; Figure 2 This is a flowchart of the water level well depth determination method proposed in this invention; Figure 3 This is a schematic diagram of the multifunctional water level meter proposed in this invention; Figure 4 This is a schematic diagram of the multifunctional water level gauge proposed in this invention; Figure 5 This is a flowchart of the water level discharge monitoring method proposed in this invention.

[0020] In the diagram: h1, liquid level scale value; h2, depth increment data; h3, dynamic liquid level depth; h4, total liquid column height; H, total depth value; 1, touch display screen; 2, operation panel; 3, cable reel; 4, signal transmission line; 5, charging interface; 6, switch button; 7, signal transmission line interface; 8, monitoring wellhead; 9, multi-functional water level gauge probe; 10, monitoring well filling filter media; 11, water in the monitoring well. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It must be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to constitute any limitation on the scope of protection of this invention. Therefore, all equivalent changes or modifications conceived by those skilled in the art based on the content disclosed in this invention without inventive effort should fall within the scope of protection claimed by this invention.

[0022] Reference Figures 1 to 5 This invention provides an intelligent groundwater joint measurement method, the technical solution of which is as follows: Example 1: Reference Figure 1 This embodiment proposes an intelligent groundwater joint measurement method, including: After the water level gauge is started, it automatically detects the current atmospheric pressure, sets and stores the atmospheric pressure as the pressure zeroing reference. The water level gauge is lowered into the container to be measured. When it first contacts the liquid surface, a liquid level scale value is generated through gauge pressure co-measurement. The hydrostatic pressure value below the liquid surface is measured and output in real time based on the pressure zeroing benchmark. The liquid level scale value and the hydrostatic pressure value are fused based on hydrostatic compensation, and measurement correction is performed to output the dynamic liquid level depth. When the water level gauge touches the bottom of the container to be measured, the bottoming event is marked by the final pressure measurement at the bottom; the maximum value of the hydrostatic pressure during the entire descent is locked and output as the total liquid column height; the total depth value is obtained by combining the liquid level scale value and the total liquid column height, and all liquid information is integrated into joint measurement data; During the descent process, the liquid level change of the dynamic liquid level depth is continuously calculated; when the liquid level change exceeds the liquid level fluctuation threshold, the liquid level over-limit alarm is automatically triggered.

[0023] Furthermore, the specific implementation process of automatically detecting the current atmospheric pressure after the water level gauge is started, setting and storing the atmospheric pressure as the pressure zeroing reference includes: The pressure sensor built into the water level gauge collects and records the air pressure data of the current environment and uses it as the raw atmospheric pressure sample. The raw atmospheric pressure sample is filtered to remove abnormal pressure readings caused by environmental airflow disturbances. The average atmospheric pressure is calculated and stored as the pressure zeroing reference.

[0024] Specifically, before the measurement begins, a stable and reliable atmospheric pressure zeroing baseline needs to be established to accurately calibrate subsequent hydrostatic pressure measurements. After the operator activates the intelligent water level gauge, its built-in high-precision pressure sensor immediately begins automatically collecting and recording air pressure data from the current environment. During the initial 5-second sampling period, the sensor continuously collects 100 raw atmospheric pressure samples at a frequency of 20 Hz. Data shows that the pressure readings during this period fluctuate between 101.25 kPa and 101.45 kPa. However, due to gusts of wind at the site, several abnormal pressure readings appeared in the data sequence, jumping to 101.80 kPa and dropping to 100.90 kPa. These abnormal readings were caused by instantaneous disturbances in the ambient airflow, affecting the accuracy of the pressure zeroing baseline.

[0025] To eliminate this environmental interference, this embodiment applies a median average filtering algorithm. This algorithm first sorts the 100 collected pressure data samples and removes the highest and lowest 5% of data points, thus eliminating extreme high and low values ​​caused by sudden factors such as gusts. Then, an arithmetic mean is calculated on the remaining 90 valid pressure data samples. Through this filtering and averaging process, a stable and accurate pressure average value reflecting the current static atmospheric environment is obtained, resulting in a pressure zeroing baseline of 101.35 kPa.

[0026] This embodiment automatically collects atmospheric pressure samples before measurement and uses a filtering algorithm to process the samples, removing abnormal pressure readings caused by airflow disturbances in the field environment. This results in a more accurate and stable pressure zeroing benchmark, effectively improving the accuracy of groundwater level calibration measurements.

[0027] Furthermore, the specific process of lowering the water level gauge into the container to be measured, and generating a liquid level scale value through gauge pressure-assisted measurement upon initial contact with the liquid surface, includes: The moment the electrode sensor of the water level gauge comes into contact with the liquid surface, a closed loop is formed due to the conductivity of the liquid, triggering a liquid surface contact signal. The water level gauge receives the liquid surface contact signal and starts the ruler-pressure collaborative measurement, immediately locking the real-time release length of the synchronously descending scale steel ruler and outputting the liquid level scale value. The ruler-pressure collaborative measurement constructs a multi-source data fusion processing framework and performs structural compensation according to the initial absolute depth benchmark.

[0028] Specifically, the operator uses an intelligent water level gauge to vertically lower its probe into the well. The probe tip integrates a pair of exposed electrode sensors spaced 5 mm apart, which are lowered synchronously with a steel ruler with millimeter-accurate graduations. During the descent, when the electrode sensors descend at a constant speed of 0.5 meters per second and first contact the groundwater surface, a weak current instantaneously forms a stable closed loop between the two electrodes due to the natural conductivity of the mineral-containing groundwater. This closed loop immediately triggers a liquid surface contact signal inside the probe, with a response time of less than 5 milliseconds. This highly sensitive liquid surface contact signal, acting as a high-priority interrupt command, is sent in real-time to the water level gauge to initiate ruler-pressure coordinated measurement.

[0029] After measurement is initiated, the ruler-pressure coordinated measurement initializes a data structure containing two fields: "steel ruler length" and "probe offset," based on the constructed multi-source data fusion processing framework. The "probe offset" field is pre-written through a calibration program, which obtains the value by placing the probe electrode on a known zero-point plane, reading the steel ruler reading, and calculating the difference. The "liquid surface contact signal" serves as an interrupt signal, switching the water level gauge from "standby" to "water contact lock" state and locking the current value of the "steel ruler length" field. The "steel ruler length" is added to the "probe offset," and the result is stored in the "liquid level scale value" field. Finally, the system switches to "data output" state and outputs the value of this field.

[0030] In one specific measurement, the released length reading of the locked steel tape was 32.768 meters. This value was confirmed as the initial liquid level scale value, representing the vertical distance from the measurement reference point at the top of the well casing to the groundwater surface.

[0031] This embodiment utilizes a liquid conductivity-triggered high-sensitivity electrode sensor to achieve instantaneous, automated, and accurate identification of the liquid surface, greatly improving the accuracy and repeatability of the initial contact depth measurement. The ruler-pressure co-measurement uses the graduated steel ruler measurement value as the initial liquid level scale value, establishing an objective and reliable depth benchmark for subsequent hydrostatic pressure measurements.

[0032] Furthermore, the specific implementation process of measuring and outputting the hydrostatic pressure value below the liquid level in real time based on the aforementioned pressure zeroing reference includes: After the water level gauge descends and enters below the liquid surface, the built-in pressure sensor continuously collects the current absolute pressure value, forming a mixed pressure data stream containing atmospheric pressure and hydrostatic pressure. Differential operation is performed on each pressure sample value in the mixed pressure data stream to remove the atmospheric pressure component represented by the pressure zeroing reference, constructing a pure hydrostatic pressure data sequence. After the pure hydrostatic pressure data sequence is formatted, the hydrostatic pressure value is output.

[0033] Specifically, in a preferred embodiment, the still water level in the groundwater monitoring well is approximately 32 meters below the wellhead. At the start of the measurement task, the device automatically detects and stores a stable atmospheric pressure zeroing baseline of 99.85 kPa based on the current surface environment. Once the operator lowers the probe of the water level gauge and successfully enters below the liquid surface, the built-in pressure sensor begins to continuously collect the absolute pressure value at the current location at a frequency of 50 times per second.

[0034] As the probe descends underwater, the pressure sensor acquires a mixed pressure data stream containing a constant atmospheric pressure component and a hydrostatic pressure component that increases linearly with depth. For example, when the probe has just entered the water about 10 centimeters below the surface, the sensor acquires an absolute pressure reading of 100.83 kPa; when the probe descends to a depth of 5 meters, the acquired absolute pressure reading rises to 148.85 kPa. Differential calculations are performed in real time on each pressure sample value in the mixed pressure data stream, subtracting a previously stored pressure zeroing baseline of 99.85 kPa. The result shows that the hydrostatic pressure at 10 centimeters underwater is 0.98 kPa, while the hydrostatic pressure at a depth of 5 meters is 49.00 kPa. This data sequence accurately reflects the pressure changes caused solely by the weight of the liquid column itself. Finally, this purified hydrostatic pressure data sequence, obtained through real-time calculations, is converted into floating-point format and output as hydrostatic pressure values ​​via internal bus data formatting.

[0035] This embodiment achieves high-precision dynamic separation of fluid static pressure values ​​by subtracting an atmospheric pressure reference from a mixed pressure measurement that includes atmospheric pressure. This differential calculation mechanism ensures that the output static pressure value is highly correlated with the liquid depth, thereby improving the accuracy of underwater depth measurements.

[0036] Furthermore, the specific implementation process of merging the liquid level scale value and the fluid static pressure value based on static pressure compensation, and performing measurement correction to output the dynamic liquid level depth includes: Based on liquid density and gravitational acceleration, the hydrostatic pressure value of the fluid is continuously calculated into depth increment data through a pressure-depth conversion processor; the depth increment data is superimposed on the liquid level scale value to generate a preliminary dynamic depth sequence; the water temperature data of the water level gauge's built-in temperature sensor is called, and the buoyancy change of the scale steel ruler at different immersion depths is calculated to measure and correct the preliminary dynamic depth sequence, and the dynamic liquid level depth is output.

[0037] Specifically, in a preferred embodiment, the device first determines the initial liquid level scale value from the wellhead reference point to the water surface to be 55.420 meters through a combined ruler and pressure measurement. As the measuring probe continues to descend below the water surface, the real-time pure fluid static pressure value at that point is measured to be 98.25 kPa.

[0038] The pressure-depth conversion processor, based on the local gravitational acceleration (9.788 m / s²) and the groundwater sample density obtained through water quality analysis (1002.5 kg / m³), continuously calculates the measured hydrostatic pressure of 98.25 kPa as a depth increment of 9.998 meters. This depth increment is then superimposed in real time onto the previously locked initial liquid level scale value of 55.420 meters, resulting in an initial dynamic depth reading of 65.418 meters. The water density is finely adjusted based on the water temperature measured by a temperature sensor and used to calculate the buoyancy change experienced by the graduated steel ruler (made of 304 stainless steel, with a cross-sectional dimension of 12.5 mm × 0.5 mm) at the current immersion depth. Due to the presence of buoyancy, the self-weight tension of the submerged portion of the steel ruler decreases, causing a slight elastic recoil and introducing measurement error. The water level gauge automatically calculates the buoyancy correction amount and compensates for it in the initial dynamic depth sequence, outputting a more accurate dynamic liquid level depth value after compensation and correction.

[0039] This embodiment integrates the liquid level scale value with the hydrostatic pressure measurement value, balancing the accuracy of static positioning with the sensitivity of dynamic tracking. A buoyancy change correction mechanism based on real-time water temperature data is introduced to compensate for physical errors previously caused by the interaction between the measuring medium (scaled steel ruler) and the measured medium (water) in precision measurements, effectively improving the rigor and accuracy of depth measurement.

[0040] Furthermore, the specific implementation process of using the final pressure measurement at the bottom of the container to be measured to identify the bottom-touching event when the water level gauge contacts the bottom includes: During the descent of the water level gauge, the gradient of the hydrostatic pressure value within the sliding time window is continuously calculated; the final pressure measurement at the bottom is performed according to the pressure stability judgment criterion to distinguish whether the gradient of the hydrostatic pressure value belongs to the normal descent state or the bottoming state; when the gradient of the hydrostatic pressure value is identified as the bottoming state, a bottoming event identifier is immediately generated.

[0041] Specifically, as the water level gauge probe continues to descend, the gradient of the fluid static pressure value within a sliding time window of 1 second is continuously calculated at a frequency of 20 Hz. The measured fluid static pressure value increases linearly, and the calculated pressure gradient remains stably within the range of 4.5 kPa / s to 5.0 kPa / s.

[0042] The pressure stability judgment criterion for bottom-sinking final pressure measurement continuously monitors the pressure gradient value calculated within the sliding time window. The selection of the window length is based on a comprehensive consideration of the typical descent speed of the probe and the sampling rate of the sensor to ensure that the window contains enough data points to smooth noise and accurately reflect the trend. The pressure stability judgment criterion includes two key parameters: gradient threshold and duration threshold. The gradient threshold is set based on the fact that its value is much smaller than the theoretical pressure gradient generated by the increase in water depth during normal descent, but is sufficient to be higher than the noise level of the sensor itself. The duration threshold is determined based on the descent speed of the water level gauge.

[0043] The pressure gradient was still 4.8 kPa / s just before the probe contacted the bottom of the well. During the sliding time window after contact, because the probe position remained unchanged, the 20 consecutive pressure readings collected were almost identical, fluctuating slightly around 735.50 kPa with a range of no more than 0.01 kPa. When the hydrostatic pressure gradient remained below 0.05 kPa for 0.5 seconds, the final pressure measurement at the bottom determined a change in the level gauge's state according to the pressure stability criterion, immediately generating and outputting a bottom-contact event flag.

[0044] This embodiment analyzes the liquid pressure gradient to automatically identify the state changes of the water level gauge probe, improving measurement accuracy. This effectively filters out instantaneous pressure fluctuations caused by water flow disturbances, ensuring that the event indicator is only triggered when the probe truly and stably touches the bottom, effectively avoiding misjudgments caused by brief hovering during descent.

[0045] Furthermore, the specific implementation process of locking the maximum value of the hydrostatic pressure during the entire downward movement and outputting it as the total liquid column height includes: After the water level gauge is immersed in the liquid surface, the maximum pressure recording value is initialized, and each new hydrostatic pressure value is compared with the currently stored maximum pressure recording value, and the maximum pressure recording value is continuously updated; when the bottoming event flag is received, the hydrostatic pressure value is stopped and the maximum pressure recording value is locked; the maximum pressure recording value is transmitted to the physical quantity conversion sensor, and the total liquid column height is calculated and output according to the fluid physical parameters.

[0046] Specifically, during the descent of the water level gauge, the stored maximum pressure record is initialized to zero. Once the measuring probe is submerged, each new hydrostatic pressure value acquired is compared in real-time with the currently stored maximum pressure record. In the initial stages of descent, any new pressure reading will be greater than zero, thus continuously updating the maximum pressure record. For example, when the probe descends to 50 meters, the measured hydrostatic pressure is 480.50 kPa, which becomes the current maximum pressure record. When the probe continues to descend to 75 meters, the measured hydrostatic pressure is 720.75 kPa, and the maximum pressure record is updated to 720.75 kPa.

[0047] Once the probe finally reaches the bottom of the well and a precise "bottom-reaching event indicator" is generated and issued by the bottom-reaching final pressure measurement, the process stops receiving any new hydrostatic pressure values ​​and locks in the currently stored maximum pressure record value. The locked maximum pressure record value is 735.50 kPa. This value, representing the maximum hydrostatic pressure at the bottom of the well, is transmitted to a physical quantity conversion sensor. Based on fluid physical parameters such as the average density of geothermal water (975.0 kg / m³) and the local gravitational acceleration (9.792 m / s²), the pressure value is precisely converted into a total liquid column height of 76.98 meters and output.

[0048] This embodiment automatically tracks and locks the maximum value of the hydrostatic pressure throughout the entire descent process, ensuring that the obtained total liquid column height is an accurate calculation based on the true physical pressure at the deepest point. This effectively avoids the problem of unstable pressure readings at the endpoint and improves the accuracy of the total liquid column height measurement.

[0049] Furthermore, the specific implementation process of combining the liquid level scale value and the total liquid column height to obtain the total depth value, and integrating all liquid information into joint measurement data includes: The liquid level scale value recorded during the measurement process is retrieved, and the liquid level scale value is arithmetically superimposed with the total liquid column height to calculate the total depth value representing the distance from the measurement reference point to the bottom of the container. The liquid level scale value, dynamic liquid level depth, total liquid column height, and total depth value are integrated and packaged into joint measurement data containing multiple liquid physical dimension information.

[0050] Specifically, during the measurement process, the initial liquid level scale value from the measurement reference point to the liquid surface was recorded as 2.855 meters using a ruler-pressure combined measurement. The maximum hydrostatic pressure value when the probe touched the bottom was locked, and the total liquid column height was calculated to be 18.750 meters.

[0051] The liquid level reading (2.855 meters) recorded at the initial stage of measurement, serving as a static reference, was retrieved. This reading was then arithmetically superimposed with the previously determined total liquid column height (18.750 meters), representing the distance from the liquid surface to the bottom, to calculate the total depth from the measurement reference point to the bottom of the container, which was 21.605 meters. The liquid level readings from this measurement process, the dynamically adjusted liquid level depth, the total liquid column height representing the actual liquid filling volume, and the newly calculated total depth value were then structurally integrated and packaged into a joint measurement data package containing information on multiple liquid physical dimensions. This package was then output to the human-machine interface of the water level gauge in a standard data format, completing the intelligent joint measurement of groundwater.

[0052] This embodiment generates a multi-dimensional, information-rich joint measurement dataset by logically integrating and arithmetically performing multiple key data points generated during continuous measurement. This dataset simultaneously contains three key parameters: liquid level, liquid column height, and total container depth, providing a complete three-dimensional view of the internal state of the measured container.

[0053] Furthermore, the specific implementation process of continuously calculating the liquid level change of the dynamic liquid level depth during the descent includes: The continuously output dynamic liquid level depth is sent to the data buffer sensor in real time and temporarily stored as a historical depth data sequence; the latest dynamic liquid level depth is extracted in each calculation cycle, and the historical depth value corresponding to the previous calculation cycle is retrieved from the data buffer sensor; a difference operation is performed on the dynamic liquid level depth and the historical depth value to generate the liquid level change amount representing the direction of liquid level rise and fall.

[0054] Specifically, when the measuring probe of the water level gauge is suspended below the liquid surface, the continuously output dynamic liquid level depth data stream, after various compensation and corrections, is sent to the high-speed data buffer sensor in real time to dynamically store the historical depth data sequence within the last 5 seconds.

[0055] The calculation cycle is 200 milliseconds. At the beginning of each cycle, the latest dynamic liquid level depth is extracted from the real-time data stream. For example, in one calculation cycle, the latest dynamic liquid level depth is extracted to be 15.882 meters. Simultaneously, the historical depth value stored in the data cache sensor from the previous calculation cycle (i.e., 200 milliseconds ago) is retrieved; this value is 15.875 meters. Immediately afterwards, a difference operation is performed on these two values: the latest dynamic liquid level depth is subtracted from the immediately preceding historical depth value. The result generates a liquid level change of -0.007 meters. This negative value precisely represents that the reservoir's water level actually dropped by 7 millimeters in the past 200 milliseconds. This calculation process is continuously executed in a loop, generating a continuous, high-resolution liquid level change data stream that reflects the direction and rate of water level rise and fall in real time.

[0056] This embodiment converts a series of static absolute depth readings into a dynamic change data stream that directly characterizes the liquid surface movement state by performing real-time high-frequency differential operations on continuous depth data, providing high-value dynamic data for the groundwater measurement process.

[0057] Furthermore, the specific implementation process for automatically triggering a liquid level over-limit alarm when the liquid level change exceeds the liquid level fluctuation threshold includes: The liquid level change is input to the early warning judgment sensor and compared with the liquid level fluctuation threshold. When the absolute value of the liquid level change exceeds the liquid level fluctuation threshold, an over-limit alarm signal is immediately generated. The over-limit alarm signal is sent to the human-machine interface to provide audible and visual alarms for abnormal liquid level fluctuations.

[0058] Specifically, the change in groundwater level is input into the early warning sensor in real time and compared with the level fluctuation threshold set according to the hydrogeological conditions of the monitoring well.

[0059] Initially, the well's liquid level fluctuated gently, with the calculated change consistently remaining within the range of 0.2 to 0.3 meters per minute, its absolute value not exceeding the 0.5 meter / minute threshold. However, with sudden rainfall, the well's liquid level began to rise sharply. In the subsequent calculation cycle, the level gauge calculated the latest change to be 0.65 meters per minute. The warning sensor, when comparing the values, determined that the absolute value of this change (0.65 meters / minute) clearly exceeded the 0.5 meter / minute threshold. At the moment of detection, the sensor generated a high-level over-limit alarm signal, immediately sending it to the device's human-machine interface. This caused the LED indicator to flash rapidly three times per second, and the buzzer to emit an intermittent high-pitched alarm at 90 decibels, providing audible and visual alarm for abnormal liquid level fluctuations.

[0060] This embodiment utilizes a water level gauge to detect and warn of abnormal fluctuations in the liquid level in real time, providing timely and reliable early warning information for the groundwater measurement process, and achieving a comprehensive improvement in measurement accuracy, data dimensions, and safety early warning capabilities.

[0061] Example 2: This embodiment fully deploys the aforementioned intelligent groundwater joint measurement method in a well-washing sampling project for groundwater in area X, referring to... Figure 2 and Figure 3 This enables the measurement of water level and well depth in monitoring well JW-08.

[0062] Before conducting measurement operations on the JW-08 groundwater monitoring well, the operators activated a reference system near the wellhead. Figure 4 The multi-functional water level gauge shown includes: a touch screen 1, an operation panel 2, a cable reel 3, and a signal transmission line 4. The JW-08 groundwater monitoring well includes: a charging interface 5, a switch button 6, a signal transmission line interface 7, and a multi-functional water level probe 9; the well also includes: a monitoring well opening 8, a monitoring well filling filter material 10, and water 11 inside the monitoring well; the well is expected to measure and obtain the following values: liquid level scale value h1, depth increment data h2, dynamic liquid level depth h3, total liquid column height h4, and total depth value H.

[0063] Furthermore, after the water level gauge is activated, its built-in high-precision pressure sensor automatically begins collecting air pressure data under the current environment. During the initial 5-second sampling period, the sensor continuously collects 100 raw atmospheric pressure samples at a frequency of 20 Hz. Data shows that the pressure readings during this period fluctuate normally between 98.80 kPa and 99.25 kPa. However, due to light wind disturbances, several abnormally high values ​​jump to 99.50 kPa and abnormally low values ​​drop to 98.70 kPa appear in the data sequence. To eliminate these abnormal readings caused by environmental airflow disturbances, the water level gauge's built-in processor begins executing a median average filtering algorithm. First, the 100 collected pressure data samples are numerically sorted, and the highest and lowest 5% of data points are removed to exclude extreme values ​​caused by sudden factors such as gusts. An arithmetic mean is then calculated from the remaining 90 valid pressure sample data to obtain the current static atmospheric pressure average (99.05 kPa), which is stored as the pressure zeroing baseline.

[0064] Furthermore, the operator lowered the measuring probe of the water level gauge into the JW-08 monitoring well at a constant speed. The probe's end integrates a pair of exposed electrode sensors spaced 5 mm apart, which were lowered synchronously with a 304 stainless steel ruler with millimeter-accurate graduations. During the descent, the moment the electrode sensors first contacted the groundwater surface in the well, due to the natural conductivity of the minerals in the groundwater, a weak current instantaneously formed a stable closed loop between the two electrodes through the water-electric medium. The formation of this closed loop immediately triggered a liquid surface contact signal inside the probe, which was sent to the water level gauge in real time, initiating the ruler-pressure coordinated measurement. Upon receiving the signal, the real-time release length of the graduated steel ruler, which was lowered synchronously with the electrode sensors, was immediately read and locked, yielding a reading of 15.455 meters. Simultaneously, this ruler-pressure coordinated measurement performed a structural compensation value based on the initial absolute depth reference. This compensation value was pre-calibrated based on the actual installation offset of the probe electrode tip relative to the physical zero point of the graduated steel ruler; in this embodiment, it was +1.5 cm. This compensation value is automatically superimposed on the locked steel ruler length, thereby outputting the structurally compensated initial liquid level scale value, indicating that the vertical distance from the measurement reference point at the top of the well casing to the groundwater surface is 15.470 meters.

[0065] Furthermore, after the probe descends below the liquid surface, its built-in pressure sensor continuously collects the current absolute pressure value at a frequency of 50 times per second, forming a mixed pressure data stream that includes a constant atmospheric pressure component and a hydrostatic pressure component that increases linearly with depth. To accurately separate the pressure generated purely by the water column, the level gauge processor performs a differential operation on each pressure sample value in this mixed pressure data stream in real time. Specifically, a previously stored pressure zeroing reference of 99.05 kPa is subtracted from each newly acquired absolute pressure sample value. For example, when the probe is 1 meter underwater, the acquired absolute pressure reading is 108.85 kPa; subtracting the atmospheric pressure reference yields a pure hydrostatic pressure value of 9.80 kPa. This operation removes the atmospheric pressure component as a background value, thus constructing a pure hydrostatic pressure data sequence, which is then continuously output in kPa after data formatting processing via the internal bus.

[0066] Furthermore, the water level gauge integrates the liquid level scale value and the hydrostatic pressure value based on static pressure compensation and performs measurement corrections to output a high-precision dynamic liquid level depth. The pressure-to-depth conversion processor built into the water level gauge reads the density value of the geothermal sample (1005 kg / m³) and the local gravitational acceleration value (9.79 m / s²), continuously calculating the real-time output of the pure fluid hydrostatic pressure value as depth increment data. These depth increment data are then superimposed in real-time onto the previously locked initial liquid level scale value of 15.470 meters, thereby generating a preliminary dynamic depth sequence. During this process, the temperature sensor built into the water level gauge simultaneously measures the well water temperature at 14.5 degrees Celsius. Based on this water temperature data, the processor looks up the precise water density at the corresponding temperature using the built-in water physical property parameter table. Based on this density, the system further calculates the buoyancy change experienced by the graduated steel ruler (made of 304 stainless steel, with a cross-sectional size of 12.5 mm × 0.5 mm and an elastic modulus of approximately 193 GPa) at the current immersion depth. Due to buoyancy, the submerged portion of the steel ruler experiences a decrease in tension due to its own weight, causing a slight elastic recoil and introducing a negative measurement error. The water level gauge can quantitatively calculate this elastic recoil and use it as a correction value to compensate for the initial dynamic depth sequence. After this correction, the final output is a compensated, more accurate dynamic liquid level depth value.

[0067] Furthermore, as the water level probe continues to descend and approaches the bottom of the well, the final pressure measurement at the bottom is activated to identify a bottom-touching event. Throughout the descent, the hydrostatic pressure data sequence is continuously processed within a 1.5-second sliding time window, and the pressure gradient is calculated by performing least-squares linear regression on the data points within the window. During normal descent, the pressure gradient remains stable at approximately 9.8 kPa / s. When the pressure gradient remains below 0.1 kPa / s for more than 0.8 seconds, the final pressure measurement at the bottom determines that the water level probe has reached the bottom state according to the pressure stability criterion. At this point, the pressure sensor reading stabilizes around 245.55 kPa and stops increasing, thus immediately generating a bottom-touching event marker. Upon receiving this bottom-touching event marker, the water level probe immediately stops receiving new hydrostatic pressure values ​​and ultimately locks in the maximum hydrostatic pressure value recorded throughout the descent, which is 245.55 kPa. Subsequently, the maximum pressure record value was transmitted to a physical quantity conversion sensor, which, based on known fluid physical parameters (density and gravitational acceleration), accurately calculated and output the total liquid column height as 24.942 meters.

[0068] Furthermore, the water level gauge automatically retrieves the static baseline liquid level reading (15.470 meters) recorded during the initial measurement phase and performs an arithmetic superposition operation with the previously calculated total liquid column height (24.942 meters), representing the distance from the liquid surface to the bottom of the well. This operation yields a total depth of 40.412 meters, representing the distance from the measurement reference point (wellhead) to the bottom of the container (well bottom). Finally, the core parameters—liquid level reading, dynamic liquid level depth, total liquid column height, and total depth—are integrated and packaged into a joint measurement data package containing information on multiple liquid physical dimensions. This data package is then output to the human-machine interface in a standard data format, achieving a complete intelligent joint measurement of the JW-08 monitoring well.

[0069] Example 3: This embodiment fully deploys the aforementioned intelligent groundwater joint measurement method in the contaminated groundwater remediation project of Y Chemical Plant, referring to... Figure 5 This enables the measurement of changes in water levels containing VOCs.

[0070] To prevent wellbore collapse or water flow turbulence, the water level drop during the measurement process must not exceed 10 centimeters. Before the measurement operation began, on-site technicians precisely calibrated the initial water level of the monitoring well, confirming the current dynamic liquid level depth to be 8.750 meters. The technicians then switched the water level gauge to "water level monitoring" mode. In this mode, the technicians input the corresponding alarm trigger conditions according to the operational requirements, setting the drop alarm threshold to -0.10 meters.

[0071] The level gauge continuously calculates the liquid level change every 200 milliseconds. Within each calculation cycle, the processor extracts the dynamic liquid level depth reading and retrieves historical depth values ​​stored in the high-speed data cache sensor from the previous calculation cycle (i.e., 200 milliseconds ago). By performing a differential operation between the latest depth value and the immediately preceding historical depth value, the level gauge generates a data stream characterizing the direction and rate of liquid level rise and fall within a very short time. Initially, the liquid level change generated in each calculation cycle is approximately -0.001 meters (i.e., 1 millimeter). This real-time calculated liquid level change is continuously input into the early warning judgment sensor.

[0072] Inside the early warning sensor, the level gauge compares the absolute value of the received liquid level change with the absolute value of a preset liquid level fluctuation threshold in real time. At this point, the calculated absolute value of the liquid level change (e.g., 0.001 meters) is much smaller than the set threshold (0.10 meters). About 15 minutes into the measurement, due to localized changes in formation permeability, the rate of water level drop in the well suddenly accelerates. The level gauge detects a drop of -0.095 meters. In the next calculation cycle, the latest liquid level change reading shows a drop of -0.102 meters. At this point, the early warning sensor, during the comparison, determines that the absolute value of the liquid level change (0.102 meters) has exceeded the absolute value of the liquid level fluctuation threshold (0.10 meters).

[0073] Upon detecting an exceedance, the warning sensor immediately generates a high-level liquid level over-limit alarm signal and sends it to the audible and visual alarm sensor on the human-machine interface. A red LED indicator on the interface flashes rapidly three times per second, and a buzzer emits an intermittent high-pitched alarm sound with an intensity of up to 90 decibels, thus measuring the water level change.

[0074] It should be clarified that the embodiments described above are merely exemplary and are intended to aid in understanding the present invention, not to limit it. Those skilled in the art can make various changes and modifications after grasping the core ideas of the present invention. Therefore, the scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A smart groundwater joint measurement method, characterized in that, include: After the water level gauge is started, it automatically detects the current atmospheric pressure, sets and stores the atmospheric pressure as the pressure zeroing reference. The water level gauge is lowered into the container to be measured. When it first contacts the liquid surface, a liquid level scale value is generated through gauge pressure co-measurement. The hydrostatic pressure value below the liquid surface is measured and output in real time based on the pressure zeroing benchmark. The liquid level scale value and the hydrostatic pressure value are fused based on hydrostatic compensation, and measurement correction is performed to output the dynamic liquid level depth. When the water level gauge contacts the bottom of the container to be measured, the bottoming-out event is identified using the final pressure measurement. Specifically, during the water level gauge's descent, the hydrostatic pressure data sequence is continuously processed within a sliding time window determined by the probe's descent speed and sensor sampling rate. The gradient of the hydrostatic pressure value is calculated by performing least-squares linear regression on the data points within the sliding time window. The final pressure measurement distinguishes between a normal descent state and a bottoming-out state based on a pressure stability judgment criterion, which includes a gradient threshold and a duration threshold. When the gradient of the hydrostatic pressure value is continuously less than the gradient threshold for a period exceeding the duration threshold, the gradient of the hydrostatic pressure value is identified as a bottoming-out state, and a bottoming-out event identifier is immediately generated. The maximum value of the hydrostatic pressure value during the entire descent process is locked and output as the total liquid column height. The total depth value is obtained by combining the liquid level scale value and the total liquid column height, and all liquid information is integrated into joint measurement data. During the descent process, the liquid level change of the dynamic liquid level depth is continuously calculated; when the liquid level change exceeds the liquid level fluctuation threshold, the liquid level over-limit alarm is automatically triggered.

2. The intelligent groundwater joint measurement method according to claim 1, characterized in that, The specific implementation process of automatically detecting the current atmospheric pressure after the water level gauge is started, setting and storing the atmospheric pressure as the pressure zeroing reference includes: The pressure sensor built into the water level gauge collects and records the air pressure data of the current environment and uses it as the raw atmospheric pressure sample. The raw atmospheric pressure sample is filtered to remove abnormal pressure readings caused by environmental airflow disturbances. The average atmospheric pressure is calculated and stored as the pressure zeroing reference.

3. The intelligent groundwater joint measurement method according to claim 1, characterized in that, The specific process of lowering the water level gauge into the container to be measured, and generating a liquid level scale value through gauge pressure-assisted measurement upon initial contact with the liquid surface, includes: The moment the electrode sensor of the water level gauge comes into contact with the liquid surface, a closed loop is formed due to the conductivity of the liquid, triggering a liquid surface contact signal. The water level gauge receives the liquid surface contact signal and starts the ruler-pressure collaborative measurement, immediately locking the real-time release length of the synchronously descending scale steel ruler and outputting the liquid level scale value. The ruler-pressure collaborative measurement constructs a multi-source data fusion processing framework and performs structural compensation according to the initial absolute depth benchmark.

4. The intelligent groundwater joint measurement method according to claim 1, characterized in that, The specific implementation process of measuring and outputting the hydrostatic pressure value below the liquid level in real time based on the aforementioned pressure zeroing benchmark includes: After the water level gauge descends and enters below the liquid surface, the built-in pressure sensor continuously collects the current absolute pressure value, forming a mixed pressure data stream containing atmospheric pressure and hydrostatic pressure. Differential operation is performed on each pressure sample value in the mixed pressure data stream to remove the atmospheric pressure component represented by the pressure zeroing reference, constructing a pure hydrostatic pressure data sequence. After the pure hydrostatic pressure data sequence is formatted, the hydrostatic pressure value is output.

5. The intelligent groundwater joint measurement method according to claim 1, characterized in that, The specific implementation process of outputting dynamic liquid level depth based on the fusion of liquid level scale value and fluid static pressure value through static pressure compensation and measurement correction includes: Based on liquid density and gravitational acceleration, the hydrostatic pressure value of the fluid is continuously calculated into depth increment data through a pressure-depth conversion processor; the depth increment data is superimposed on the liquid level scale value to generate a preliminary dynamic depth sequence; the water temperature data of the water level gauge's built-in temperature sensor is called, and the buoyancy change of the scale steel ruler at different immersion depths is calculated to measure and correct the preliminary dynamic depth sequence, and the dynamic liquid level depth is output.

6. The intelligent groundwater joint measurement method according to claim 1, characterized in that, The specific implementation process of locking the maximum value of the hydrostatic pressure during the entire descent process and outputting it as the total liquid column height includes: After the water level gauge is immersed in the liquid surface, the maximum pressure recording value is initialized, and each new hydrostatic pressure value is compared with the currently stored maximum pressure recording value, and the maximum pressure recording value is continuously updated; when the bottoming event flag is received, the hydrostatic pressure value is stopped and the maximum pressure recording value is locked; the maximum pressure recording value is transmitted to the physical quantity conversion sensor, and the total liquid column height is calculated and output according to the fluid physical parameters.

7. The intelligent groundwater joint measurement method according to claim 1, characterized in that, The specific implementation process of obtaining the total depth value by combining the liquid level scale value and the total liquid column height, and integrating all liquid information into joint measurement data includes: The liquid level scale value recorded during the measurement process is retrieved, and the liquid level scale value is arithmetically superimposed with the total liquid column height to calculate the total depth value representing the distance from the measurement reference point to the bottom of the container. The liquid level scale value, dynamic liquid level depth, total liquid column height, and total depth value are integrated and packaged into joint measurement data containing multiple liquid physical dimension information.

8. The intelligent groundwater joint measurement method according to claim 1, characterized in that, The specific implementation process of continuously calculating the liquid level change of the dynamic liquid level depth during the descent includes: The continuously output dynamic liquid level depth is sent to the data buffer sensor in real time and temporarily stored as a historical depth data sequence; the latest dynamic liquid level depth is extracted in each calculation cycle, and the historical depth value corresponding to the previous calculation cycle is retrieved from the data buffer sensor; a difference operation is performed on the dynamic liquid level depth and the historical depth value to generate the liquid level change amount representing the direction of liquid level rise and fall.

9. The intelligent groundwater joint measurement method according to claim 1, characterized in that, The specific implementation process for automatically triggering a liquid level over-limit alarm when the liquid level change exceeds the liquid level fluctuation threshold includes: The liquid level change is input to the early warning judgment sensor and compared with the liquid level fluctuation threshold. When the absolute value of the liquid level change exceeds the liquid level fluctuation threshold, an over-limit alarm signal is immediately generated. The over-limit alarm signal is sent to the human-machine interface to provide audible and visual alarms for abnormal liquid level fluctuations.

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