Device, method, electronic device, and storage medium for calibrating a borehole radial stress gauge

Abstract

This application discloses an apparatus, method, electronic device, and storage medium for calibrating a borehole radial stress gauge. By placing the stress gauge in a closed pressure equalization chamber composed of a flexible hydraulic bladder and a rigid pressure-bearing frame, and applying uniform confining pressure using a hydraulic pressurization system, the full confining pressure stress state of the borehole surrounding rock is realistically reproduced. Furthermore, the signal line is led out through the end sealing assembly while ensuring pressure sealing, completely eliminating directional interference caused by uneven force in single-point loading or actual borehole simulation. Therefore, it can solve the technical problems of directional error, inability to truly reflect the full confining pressure response characteristics, and complex operation and high cost of existing calibration methods, achieving the technical effects of high calibration accuracy, realistic response characteristics, convenient operation, and low cost.

Description

Technical Field

[0001] This disclosure relates to the field of data processing technology, and in particular to an apparatus, method, electronic device, and storage medium for calibrating a borehole radial stress gauge. Background Technology

[0002] Radial borehole stress gauges, as core equipment for mine ground pressure monitoring, are widely used in stope stability assessment and rockburst disaster early warning. Related technologies utilize sensors to detect radial stress changes in the surrounding rock of the borehole, combined with data acquisition and processing systems, to construct a ground pressure monitoring system.

[0003] Existing calibration methods directly employ single-point loading with a hydraulic pillow or simulated drilling with physical objects, resulting in directional errors in the calibration results. These methods fail to accurately reflect the sensor's response characteristics under full confining pressure conditions, or the complexity of operation and the high cost of equipment negatively impact calibration efficiency. Summary of the Invention

[0004] This disclosure provides an apparatus, method, electronic device, and storage medium for calibrating a borehole radial stress gauge.

[0005] According to a first aspect of this disclosure, an apparatus for calibrating a borehole radial stress gauge is provided, comprising: Rigid load-bearing frame; A flexible hydraulic bladder is disposed on the inner wall of the rigid pressure-bearing frame, and the interior of the flexible hydraulic bladder forms a closed hydraulic cavity. A hydraulic pressurization system, which is connected to the hydraulic chamber, is used to fill the hydraulic chamber with hydraulic medium and control the pressure inside the hydraulic chamber. The two end sealing assemblies are respectively disposed at both ends of the rigid pressure-bearing frame. Each end sealing assembly has a through hole through which the signal line of the borehole radial stress gauge passes and a sealing structure for sealing the through hole.

[0006] Optionally, the rigid pressure-bearing frame is a segmented spliced ​​structure split along the axial direction, consisting of multiple arc-shaped segments connected by flanges and fasteners to form a cylindrical structure.

[0007] Optionally, the flexible hydraulic bladder has a multi-layer composite structure, comprising an inner sealing layer, a middle reinforcing layer, and an outer protective layer from the inside out.

[0008] Optionally, each of the end sealing assemblies has an annular positioning step on its inner side for axially positioning the borehole radial stress gauge to be calibrated within the rigid pressure frame.

[0009] Optionally, the device further includes a data acquisition system, which is used to connect to the signal line of the borehole radial stress gauge to acquire and record the output signal of the borehole radial stress gauge under different confining pressures in real time.

[0010] According to a second aspect of this disclosure, a method for calibrating a borehole radial stress gauge is provided, comprising: The borehole radial stress gauge to be calibrated is installed inside the flexible hydraulic bladder of the device, so that the central axis of the borehole radial stress gauge coincides with the axis of the device. The signal line is led out through the through hole of the end sealing assembly and sealed, and connected to the hydraulic pressurization system and the data acquisition system. An initial confining pressure is applied to the flexible hydraulic bladder through the hydraulic pressurization system, and the initial confining pressure is maintained for a preset time to expel residual gas in the system and test the sealing performance. Gradually increase the hydraulic pressure in the flexible hydraulic bladder to the rated maximum working pressure of the device. After each pressure level stabilizes, record the current pressure value and the corresponding output signal of the borehole radial stress gauge. After the loading is completed, the unloading is carried out in stages. During the unloading process, the output signal of the borehole radial stress gauge is recorded after the pressure of each stage stabilizes. Based on the pressure values ​​and corresponding output signals recorded during loading and unloading, the pressure sensitivity coefficient and zero-point offset of the borehole radial stress gauge are determined through data fitting.

[0011] Optionally, after determining the pressure sensitivity coefficient and zero-point offset of the borehole radial stress gauge through data fitting based on the pressure values ​​and corresponding output signals recorded during loading and unloading, the method further includes: Repeatedly execute the loading and unloading process multiple times to obtain calibrated linearity and repeatability data.

[0012] The method further includes: Generate a calibration report, which includes the original data, fitted curves, calibration coefficients, linearity index, and repeatability error index.

[0013] According to a third aspect of this disclosure, an electronic device is provided, comprising: At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the method described in the first aspect above.

[0014] According to a fourth aspect of this disclosure, a non-transitory computer-readable storage medium is provided storing computer instructions, wherein the computer instructions are configured to cause the computer to perform the method described in the first aspect above.

[0015] According to a fifth aspect of this disclosure, a computer program product is provided, comprising a computer program that, when executed by a processor, implements the method described in the first aspect above.

[0016] The device, method, electronic equipment, and storage medium for calibrating borehole radial stress gauges disclosed in this application, by placing the stress gauge in a closed pressure equalization chamber composed of a flexible hydraulic bladder and a rigid pressure-bearing frame, and applying uniform confining pressure using a hydraulic pressurization system, realistically reproduces the full confining pressure stress state of the borehole surrounding rock. Furthermore, by extending the signal line through the end sealing assembly while ensuring pressure sealing, the directional interference caused by uneven force in single-point loading or actual borehole simulation is completely eliminated. Therefore, it can solve the technical problems of directional error, inability to truly reflect the full confining pressure response characteristics, and complex operation and high cost existing calibration methods, achieving the technical effects of high calibration accuracy, realistic response characteristics, convenient operation, and low cost.

[0017] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0018] The accompanying drawings are provided to better understand this solution and do not constitute a limitation of this disclosure. Wherein: Figure 1 A schematic diagram of a device for calibrating a borehole radial stress gauge provided in an embodiment of this disclosure; Figure 2 This is a side view of a calibration device provided in an embodiment of this application; Figure 3 A schematic flowchart illustrating a method for calibrating a borehole radial stress gauge according to an embodiment of this disclosure; Figure 4 A schematic block diagram of an example electronic device provided for embodiments of this disclosure. Detailed Implementation

[0019] The exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0020] The apparatus, method, electronic device, and storage medium for borehole radial stress gauge calibration according to embodiments of the present disclosure are described below with reference to the accompanying drawings.

[0021] Figure 1 This is a schematic diagram of a device for calibrating a borehole radial stress gauge, provided in an embodiment of this disclosure.

[0022] like Figure 1 As shown, it includes: Rigid load-bearing frame; A flexible hydraulic bladder is disposed on the inner wall of the rigid pressure-bearing frame, and the interior of the flexible hydraulic bladder forms a closed hydraulic cavity. A hydraulic pressurization system, which is connected to the hydraulic chamber, is used to fill the hydraulic chamber with hydraulic medium and control the pressure inside the hydraulic chamber. The two end sealing assemblies are respectively disposed at both ends of the rigid pressure-bearing frame. Each end sealing assembly has a through hole through which the signal line of the borehole radial stress gauge passes and a sealing structure for sealing the through hole.

[0023] Radial borehole stress gauges assess rock mass stability by sensing changes in radial stress in the surrounding rock. Their measurement accuracy depends on the accurate acquisition of calibration coefficients. The calibration process requires applying uniform and controllable radial confining pressure to the sensor to simulate the actual stress state. This technical solution combines rigid constraints with flexible hydraulic pressurization to achieve uniform radial pressure in all directions on the radial borehole stress gauge.

[0024] The rigid pressure-bearing frame 1 constitutes the outer load-bearing structure of the device, providing a rigid constraint boundary for internal pressure transmission. Its inner diameter is larger than the outer diameter of the stress gauge to be calibrated to reserve space for pressure transmission. The flexible hydraulic bladder 2 is attached to the inner wall of the pressure-bearing frame, forming a closed hydraulic cavity. The hydraulic pressurization system is connected to the hydraulic cavity, filling it with hydraulic medium and precisely controlling the pressure. During pressurization, the bladder expands uniformly under the constraint of the rigid frame, applying uniform radial pressure to the stress gauge placed inside. This principle is similar to the way an arm-type blood pressure monitor applies uniform circumferential pressure to the limb, achieving uniform circumferential confining pressure on the outer surface of the sensor.

[0025] Each end of the pressure-bearing frame is equipped with an end sealing cap 3 to close the end openings and achieve a reliable seal under high pressure. Each component has a through hole for the stress gauge signal line 8 to pass through and a sealing structure to prevent leakage of high-pressure medium along the gap between the signal line 8 and the through hole. The signal line 8 can be connected to a data acquisition device after being led out through the through hole to record the stress gauge output under different pressures in real time.

[0026] The device also includes a hydraulic interface 4, a through hole 5, and a sealing assembly 6. During calibration, the radial drilling stress gauge 7 is placed at the center of the flexible hydraulic bladder 2, and the signal line 8 is led out from the through holes 5 of the sealing caps 3 at both ends. The hydraulic system pressurizes the flexible hydraulic bladder 2 through the hydraulic interface 4, and the pressure is uniformly applied to the radial drilling stress gauge 7 through the flexible hydraulic bladder 1. The data acquisition system records the stress gauge response through the signal line 8.

[0027] In one specific implementation, the pressure-bearing frame can adopt a segmented splicing structure split along the axial direction, such as multi-lobed arc-shaped components fastened together by flanges, which facilitates the installation and removal of sensors; the bladder can adopt a multi-layer composite structure, such as an inner sealing layer, an intermediate fiber reinforcement layer and an outer protective layer, which takes into account both sealing performance and pressure bearing strength; the hydraulic pressurization system can include components such as a hydraulic pump, a precision pressure valve and a pressure sensor, to achieve programmed precise pressurization and pressure stabilization control.

[0028] In some embodiments, the rigid pressure-bearing frame 1 is a segmented spliced ​​structure split along the axial direction, consisting of multiple arc-shaped segments connected by flanges and fasteners to form a cylindrical structure.

[0029] Please see Figure 2 , Figure 2 This is a side view of a calibration device provided in an embodiment of this application. The rigid pressure-bearing frame 1 adopts a segmented structure split along the axial direction, which aims to solve the problem of difficulty in inserting and removing sensors in an overall enclosed cylindrical structure. Specifically, the pressure-bearing frame is composed of two or more arc-shaped segments, each segment having a splitting surface along the frame axial direction, and the edges of the splitting surfaces of adjacent segments are respectively provided with outwardly extending flanges. Each flange has corresponding bolt holes, and adjacent segments are fastened together by through bolts, forming a complete cylindrical pressure-bearing structure after assembly. A sealing gasket can be provided between the mating surfaces of the flanges to prevent hydraulic medium from leaking along the splitting surfaces during pressurization.

[0030] When a two-lobed structure is adopted, the pressure-bearing frame is symmetrically divided into two semi-cylindrical lobes along the diameter direction, resulting in a simple structure and convenient assembly and positioning. When the radial dimension of the pressure-bearing frame is large or it is necessary to improve the overall pressure-bearing capacity, a three-lobed or even more-lobed assembly method can also be adopted. Each lobe is equally or unequally divided along the circumference to balance the relationship between ease of processing and structural strength.

[0031] The modular structure provides the pressure-bearing frame with excellent opening and closing capabilities. During calibration, the individual segments can be separated by loosening the fastening bolts. The radial borehole stress gauge to be calibrated, along with the flexible hydraulic bladder 2, can then be placed into the frame cavity. The segments are then reassembled and tightened. Disassembly is performed in reverse. This structural design eliminates the inconvenience of inserting the sensor axially through the integral cylindrical port, making it particularly suitable for applications with large sensor dimensions or where the signal cable 8 connector is non-removable.

[0032] In terms of material selection, each arc-shaped valve can be made of high-strength alloy steel, such as 42CrMo steel, to ensure that the frame does not deform significantly under high confining pressure and maintains effective rigid constraint on the flexible bladder. The inner wall of each valve should have sufficient surface finish and geometric accuracy, and the roundness error of the assembled inner cavity should be controlled within a reasonable range to ensure uniform and consistent pressure transmission along the circumferential direction when the flexible bladder expands.

[0033] In some embodiments, the flexible hydraulic bladder 2 is a multi-layer composite structure, comprising an inner sealing layer, a middle reinforcing layer, and an outer protective layer from the inside out.

[0034] The multi-layered composite structure design of the flexible hydraulic bladder 2 aims to maintain good sealing performance, structural integrity, and long-term durability while withstanding internal hydraulic pressure in the tens of megapascals. The material selection and thickness ratio of each functional layer are determined comprehensively based on the bladder's working pressure rating, media compatibility, and service life requirements.

[0035] The inner sealing layer is in direct contact with the hydraulic medium and plays a crucial role in preventing leakage. This layer can be made of oil-resistant rubber materials, such as nitrile rubber or fluororubber. These materials have good chemical compatibility with hydraulic oil and maintain stable elasticity and low permeability even under high pressure. The thickness of the inner sealing layer is determined according to the working pressure rating. It must ensure that no breakdown or leakage occurs under maximum working pressure, while also maintaining sufficient flexibility to allow the bladder to uniformly conform to the outer surface of the stress gauge under low pressure.

[0036] The intermediate reinforcing layer surrounds the inner sealing layer and is the main load-bearing layer of the bladder, bearing the internal hydraulic load. This layer is made of high-strength fibers, such as Kevlar or high-strength polyester fibers, woven or wound. The fibers are woven at a specific angle on the outer surface of the inner layer, forming a continuous ring-shaped reinforcing structure. This effectively restrains the radial expansion of the bladder during internal pressurization, preventing rupture due to over-expansion. The weaving density, number of fiber layers, and winding angle of the reinforcing layer are optimized according to the bladder's rated working pressure to achieve a balance between pressure-bearing capacity and bladder flexibility. The reinforcing layer is tightly bonded to the inner layer through hot-pressing or bonding processes, ensuring that interlayer slippage or delamination does not occur during pressurization.

[0037] The outer protective layer is located on the outermost side of the composite structure, in contact with the inner wall of the rigid pressure-bearing frame 1. This layer is made of wear-resistant materials, such as polyurethane or special wear-resistant rubber, and its function is to protect the internal reinforcing fibers and sealing layer from mechanical damage caused by friction from the inner wall of the frame, assembly operations, and repeated loading and unloading. The surface of the outer protective layer should have appropriate frictional characteristics to ensure stable positioning of the bladder on the inner wall of the frame while allowing the bladder to expand freely in the radial direction during pressurization without excessive frictional obstruction. The thickness of the outer layer should be minimized while meeting the wear-resistant protection requirements to reduce adverse effects on the overall flexibility of the bladder.

[0038] After the three-layer structure is integrally molded, the entire capsule has a closed annular shape. Its inner contour matches the outer surface contour of the stress gauge to be calibrated, and its outer contour fits tightly against the inner wall of the pressure-bearing frame. Within the rated working pressure range, the overall radial expansion of the capsule should be controlled within the design allowable range to ensure the uniformity of pressure transmission and calibration accuracy.

[0039] In some embodiments, each of the end sealing caps 3 has an annular positioning step on its inner side for axially positioning the position of the borehole radial stress gauge to be calibrated within the rigid pressure frame 1.

[0040] The annular positioning step provided on the inner side of the end sealing cap 3 is used to accurately position the stress gauge to be calibrated in the axial direction, so that it is in the center position of the rigid pressure frame 1, thereby ensuring that the stress gauge is subjected to symmetrical and uniform force along the axial direction when pressurized.

[0041] An annular positioning step is located on the end face of the end sealing cap 3 facing the inner cavity of the pressure-bearing frame, forming a concentric annular protrusion. The inner diameter of the step is slightly larger than the outer diameter of the stress gauge end, while the outer diameter matches the inner diameter of the pressure-bearing frame cavity and the inner diameter of the flexible hydraulic bladder 2. When the end sealing cap 3 is tightened onto the end of the pressure-bearing frame by fasteners, the end face of the step forms an axial limiting contact with the end face of the stress gauge, fixing the axial position of the stress gauge in the preset position within the pressure-bearing frame cavity. The steps on both end sealing caps 3 cooperate with each other to clamp and position the sensor from both axial sides, preventing the stress gauge from shifting or deflecting axially during pressurization.

[0042] The height of the positioning step is determined based on the length of the stress gauge to be calibrated and the axial dimension of the pressure-bearing frame cavity. This ensures that after the sensor is inserted, both end faces contact the positioning surfaces of the corresponding steps, and the middle measuring section of the sensor is precisely within the effective pressurization area of ​​the flexible hydraulic bladder 2. This axial positioning accuracy directly affects the uniformity of pressure on the sensor during calibration—if the sensor is axially biased to one end, its effective length exposed to the pressurization area of ​​the bladder will be asymmetrical, resulting in inconsistent radial confining pressure ranges at both ends, affecting the reliability of the calibration results.

[0043] The cross-section of the positioning step can be designed as rectangular or rectangular with a slight chamfer. A rectangular cross-section provides a clear axial limiting surface, has a simple structure, and is easy to manufacture with guaranteed precision. A shallow elastic buffer pad can be placed at the contact point between the step end face and the sensor end face to prevent rigid collisions between metal parts from damaging the sensor end. Simultaneously, the slight elastic deformation of the pad compensates for machining tolerances, resulting in a more secure and stable positioning contact.

[0044] When the pressure-bearing frame has a segmented assembly structure, the annular positioning step can be directly machined onto the inner end face of the end sealing cap 3, independent of the segmented structure of the pressure-bearing frame. Therefore, the positioning accuracy is not affected by the frame assembly gap. During installation, the two end sealing caps 3 are pressed in and tightened from both ends of the pressure-bearing frame, and the positioning step thus completes the axial constraint on the sensor. During disassembly, the sensor can be easily removed axially by loosening one end sealing cap 3, making the operation convenient.

[0045] In some embodiments, the apparatus further includes a data acquisition system for connecting to the signal line 8 of the borehole radial stress gauge to acquire and record the output signal of the borehole radial stress gauge under different confining pressures in real time.

[0046] The data acquisition system is electrically connected to the stress gauge signal line 8, which is led out from the through hole of the end sealing cap 3, forming the signal recording and processing channel of the calibration device. During the calibration pressurization process, the data acquisition system acquires and records the output signal of the stress gauge under each level of confining pressure in real time, providing raw data for the subsequent calculation of calibration coefficients.

[0047] The signal input terminal of the data acquisition system connects to the stress gauge signal line 8 via a standard connector. Depending on the type of stress gauge output signal, the acquisition system can be adapted to different signal conditioning circuits. When the stress gauge output is a frequency signal, the acquisition system has a built-in high-precision frequency counting module to accurately measure the vibrating wire frequency or piezoelectric resonant frequency of the sensor. When the output is an analog voltage signal, the acquisition system uses a built-in analog-to-digital converter to convert the analog quantity into a digital quantity, with the conversion resolution meeting the calibration accuracy requirements. When the stress gauge itself has a digital output interface, the acquisition system can directly read the digital quantity processed internally by the sensor via a standard digital communication protocol.

[0048] The data acquisition system's recording function works in conjunction with the pressurization process of the hydraulic pressurization system. After each confining pressure reaches the set value and is confirmed to be stable, the system records the corresponding stress gauge output reading. The system can simultaneously receive pressure measurements from the pressure sensors in the hydraulic pressurization system, storing the pressure data and stress gauge output signals in pairs using timestamps to form a dataset with a one-to-one correspondence between pressure values ​​and output readings, for subsequent fitting calculations. The data storage medium can be the device's built-in non-volatile memory or can be transmitted in real-time to a host computer for storage and processing.

[0049] The time sampling interval of the acquisition system can be set according to the calibration conditions. During the voltage stabilization and holding phase, the sampling interval can be appropriately increased to reduce redundant data; during the transition phase of pressurization or unloading, the sampling interval should be small enough to capture transient changes in the output signal and avoid missing important response features. After acquisition, the raw data stored in the system can be exported for calibration equation fitting and calibration quality evaluation.

[0050] Figure 3 This is a schematic flowchart illustrating a method for calibrating a borehole radial stress gauge according to an embodiment of the present disclosure.

[0051] like Figure 3 As shown, it includes: Step 101: Install the borehole radial stress gauge to be calibrated inside the flexible hydraulic bladder of the device, so that the central axis of the borehole radial stress gauge coincides with the axis of the device, lead out the signal line through the through hole of the end sealing assembly and seal it, and connect the hydraulic pressurization system and the data acquisition system. The initial stage of calibration involves the installation and system connection of the stress gauge to be calibrated. Before installation, the flexible hydraulic bladder is placed inside the rigid pressure-bearing frame, ensuring that the outer wall of the bladder fits evenly against the inner wall of the frame without wrinkles or localized gaps. Then, the radial borehole stress gauge to be calibrated is axially inserted into the center of the bladder's inner cavity, and its spatial orientation is adjusted so that the central axis of the stress gauge is substantially aligned with the common axis of the pressure-bearing frame and the bladder. Axial alignment is a prerequisite for ensuring uniform subsequent pressurization—if the sensor is significantly eccentric, the radial pressure acting on the sides of the sensor after the bladder expands will be unevenly distributed, directly affecting the accuracy of the calibration data.

[0052] After the stress gauge is in place, its signal lines are led out from the central through-holes of the end sealing components at both ends of the pressure-bearing frame. During the lead-out process, care should be taken to avoid excessive bending or clamping of the signal lines between the frame and the bladder surface, to prevent damage or seal failure caused by the bladder expanding and squeezing the signal lines during pressurization. After the signal lines pass through the through-holes, a matching sealing structure, such as a combination sealing ring or gland, is installed at the through-holes to reliably seal the annular gap between the signal lines and the through-holes. The tightness of the sealing structure needs to be moderately controlled, ensuring that the hydraulic medium does not leak along the signal line surface under the highest working pressure, while avoiding excessive tightness that could damage the outer sheath of the signal lines or affect the electrical performance of the internal conductors. After the sealing components at both ends are in place, they are locked to the ends of the pressure-bearing frame using fasteners, completing the closure of the device.

[0053] After the device is completely sealed, connect the output pipeline of the hydraulic pressurization system to the hydraulic port of the bladder. The connection shall be ensured to be reliably sealed, and there is no residual gas in the pipeline. Connect the end connectors of the led-out signal lines to the corresponding input channels of the data acquisition system respectively, confirm that the signal path is unobstructed, and the acquisition system is in a to-be-triggered working state. After all systems are connected, the process can proceed to the next stage of pre-pressurization and seal inspection.

[0054] Step 102: apply an initial confining pressure to the flexible hydraulic bladder through the hydraulic pressurization system, and keep the initial confining pressure stable for a preset time, so as to discharge the residual gas in the system and verify the sealing performance; After the hydraulic pressurization system is started, the hydraulic medium is slowly injected into the closed hydraulic cavity of the flexible hydraulic bladder at a low flow rate. During the injection process, the hydraulic medium pushes the bladder to expand uniformly in the radial direction, and gradually applies radial pressure to the outer surface of the stress gauge at the central position. The set value of the initial confining pressure usually adopts a relatively low pressure level, such as 1MPa, whose purpose is to complete the preliminary filling and gas exhaust of the system with a small pressure gradient, so as to avoid uneven pressure transfer or pressure shock caused by directly applying high pressure when gas still remains in the system.

[0055] During the injection process, the residual air in the system is gradually gathered to the high point of the bladder or the exhaust channel under the push of the hydraulic medium. As an embodiment, the hydraulic port of the bladder can be arranged near the radial highest point of the cavity, and by utilizing the physical property that the density of gas is lower than that of liquid, the residual air naturally floats upward during the pressurization process and is discharged through the port along with a small amount of returned oil. If the system is equipped with a dedicated exhaust valve, the exhaust valve can be opened under a low pressure state, and the exhaust valve is closed after no obvious bubbles are contained in the outflowing medium, so as to complete the exhaust operation.

[0056] After the initial confining pressure reaches the set value, the hydraulic pressurization system enters a pressure holding state, and maintains the pressure stable for a preset period of time, such as several minutes to more than ten minutes. The pressure holding stage undertakes two functions: first, further discharge the micro-bubbles dissolved in the hydraulic medium. These bubbles will be slowly precipitated, aggregated and discharged under the pressure stabilizing condition, eliminating their interference with the pressure transfer accuracy during subsequent staged pressurization; second, verify the overall sealing performance of the device. During the pressure holding period, the pressure sensor in the hydraulic pressurization system continuously monitors the pressure change in the cavity. If the pressure reading remains stable within the preset time without a significant downward trend, it indicates that the seal of the signal line at the end sealing assembly, the interface seal between the bladder and the frame, and the seal of the hydraulic pipeline port all meet the high-pressure working requirements. If a continuous pressure drop is monitored, it indicates that there is a leakage point. It is necessary to release the pressure, check and repair the seal, and re-perform the pre-pressurization and pressure holding verification, and the process can proceed to the formal staged loading calibration procedure only after the seal is qualified.

[0057] Step 103: Gradually increase the hydraulic pressure in the flexible hydraulic bladder to the rated maximum working pressure of the device. After each pressure level reaches stability, record the current pressure value and the corresponding output signal of the borehole radial stress gauge. After passing the pre-pressurization test, the formal graded loading calibration phase begins. The hydraulic pressurization system gradually increases the hydraulic pressure within the flexible hydraulic bladder according to a preset pressure gradient. The magnitude of each pressure increment is determined based on the calibration accuracy requirements and the sensor range. The pressure gradient should be selected to ensure a sufficient number of calibration points throughout the calibration process, guaranteeing the statistical reliability of subsequent linear fitting. Simultaneously, each pressure increment should not be too small to avoid an overly lengthy calibration process.

[0058] During each pressure increase stage, the hydraulic pressurization system regulates the injection rate of the hydraulic medium via a precision pressure valve, ensuring a smooth rise in pressure to the target set value. Due to factors such as contact deformation between the flexible bladder and the outer surface of the stress gauge, the flow inertia of the hydraulic medium within the closed cavity, and system elasticity, the pressure does not stabilize immediately upon reaching the set value. Instead, a brief transition period is required for the various physical processes to reach equilibrium. During this stage, the hydraulic pressurization system controller continuously monitors the real-time readings of the pressure sensor. When the readings no longer show significant changes within the preset fluctuation tolerance range, it is determined that the pressure at that stage has entered a steady state.

[0059] After pressure stabilization is confirmed, the data acquisition system synchronously performs one or more sampling operations, recording the current pressure value and the stress gauge's output signal. The pressure value comes from the measurement reading of the pressure sensor in the hydraulic pressurization system. This sensor has been calibrated using higher-precision standard instruments before calibration to ensure the accuracy and reliability of the pressure reference. The stress gauge's output signal is transmitted to the data acquisition system via a signal line. Depending on the sensor's operating principle, the output signal can be expressed as a vibrating wire frequency, analog voltage, or digital encoding. The acquisition system records the output signal at each pressure level and stores it in pairs with the corresponding pressure value, forming a series of discrete calibration data points—that is, a dataset of the correspondence between pressure values ​​and output readings.

[0060] After each level of data acquisition is completed, the hydraulic pressurization system continues to increase the pressure to the next target value, repeating the above pressurization, stabilization, and acquisition process, progressively covering the full range from zero pressure or initial confining pressure to the device's rated maximum working pressure. The pressure values ​​at each calibration point should ideally be approximately uniformly distributed within the range. Sufficient calibration points should be set in both the low and high range segments to comprehensively reflect the sensor's input-output response characteristics across the entire range. After all stages of loading are completed, a complete positive loading calibration dataset is obtained, which can be used for subsequent calibration coefficient calculations and linearity evaluation.

[0061] Step 104: After completing the step-by-step loading, perform staged unloading. During the unloading process, record the output signal of the borehole radial stress gauge after the pressure stabilizes at each stage. After being forward-loaded to the rated maximum working pressure, the hydraulic pressurization system enters the staged unloading phase, gradually reducing the hydraulic pressure within the flexible hydraulic bladder in the opposite direction to forward loading. The decrease in pressure at each stage of unloading corresponds to the increase in pressure during forward loading, ensuring that the pressure values ​​at each calibration point on the unloading path approximately coincide with those on the loading path. This facilitates subsequent comparative analysis of the loading and unloading data.

[0062] The hydraulic pressurization system controls the discharge rate of the hydraulic medium through a precision pressure valve, causing the pressure inside the chamber to decrease smoothly in stages. Similar to the loading process, a certain amount of time is required after each pressure decrease for the system to reach a steady state. Pressure sensors continuously monitor the real-time pressure inside the chamber. Once the reading stabilizes within the allowable fluctuation range of the target value for that stage, the data acquisition system samples and records the stress gauge output signal at the current pressure. The data recording format during the unloading process is consistent with that during the loading stage, with each pressure value and its corresponding stress gauge output reading stored in pairs.

[0063] Recording data during the unloading phase is crucial for evaluating the hysteresis characteristics of the sensor. Because the elastic sensing element of the sensor may undergo incompletely reversible micro-deformation during loading and unloading, a slight difference may appear between the output readings under the same pressure value during loading and unloading; this difference is the hysteresis error. By comparing the loading and unloading datasets point-by-point, the hysteresis index of the sensor across its entire range can be quantitatively calculated, serving as one of the important parameters for measuring calibration quality.

[0064] After unloading to zero pressure or the initial confining pressure, a single complete loading and unloading cycle is complete. To further verify the repeatability of the sensor output, the same loading and unloading process can be repeated multiple times after the first loading and unloading cycle, recording the complete data for each cycle. The consistency between multiple sets of cycle data reflects the repeatability of the sensor output; the smaller the repeatability error, the more reliable the calibration results. The average value of multiple cycle data can also be used for the final calculation of the calibration coefficients to reduce the impact of random errors in a single measurement.

[0065] Step 105: Based on the pressure values ​​and corresponding output signals recorded during the loading and unloading process, determine the pressure sensitivity coefficient and zero-point offset of the borehole radial stress gauge through data fitting.

[0066] The pressure values ​​collected throughout the loading and unloading process, along with the corresponding output signals, constitute a complete original calibration dataset. The task of the data fitting stage is to extract the linear relationship between the input and output of the stress gauge from this dataset and determine the key calibration parameters characterizing the sensor's response.

[0067] Before fitting, the raw data is preprocessed and filtered. The integrity of each calibration point is checked, and obvious outliers caused by insufficient pressure stabilization during pressurization, poor signal line contact, or occasional anomalies in the acquisition system are removed. For data acquired through multiple loading and unloading cycles, the arithmetic mean of the output readings at the same pressure level in each cycle is taken to suppress the influence of random fluctuations on the fitting results. After preprocessing, a set of ordered paired data of pressure values ​​and output readings is obtained.

[0068] The data fitting employed the least squares method to perform linear regression analysis on the aforementioned dataset. The input-output relationship of a radial borehole stress gauge within its measurement range typically approximates linearity, meaning the pressure value and output reading can be described by a linear equation. The least squares method solves for the slope and intercept of this linear equation by minimizing the sum of squares of the residuals between the measured output values ​​at each calibration point and the predicted values ​​of the linear equation. The slope is the stress gauge's pressure sensitivity coefficient, characterizing the pressure change corresponding to a unit change in output signal; the intercept is the zero-point offset, reflecting the deviation of the sensor's output signal from the ideal zero value when no external pressure is applied.

[0069] After fitting is complete, the fitting quality needs to be evaluated. The linear correlation coefficient is calculated; this coefficient reflects the degree of fit between the data points and the fitted line. The closer the value is to 1, the better the linear response characteristics of the sensor across the entire range, and the more reliable the fitting result. Provided the linear correlation coefficient meets the preset acceptable threshold, the obtained pressure sensitivity coefficient and zero-point offset are output as the formal calibration parameters for the stress gauge. If the linear correlation coefficient does not meet the acceptable standard, the cause needs to be analyzed, such as whether there is excessive nonlinearity in the sensor itself, systematic deviations in the calibration data acquisition process, or insufficient number of calibration points. If necessary, the calibration operation should be repeated.

[0070] When fitting the loading and unloading paths separately, the two sets of fitted parameters can be compared. If the differences in sensitivity coefficients and zero-point offset obtained from loading and unloading are small, it indicates that the sensor hysteresis effect is not significant. In this case, the two sets of data can be merged and fitted uniformly to obtain more statistically representative calibration parameters. If the difference between the two sets of parameters exceeds the allowable range, the loading calibration coefficients and unloading calibration coefficients should be reported separately, and the specific value of the hysteresis error should be noted in the calibration report to provide a more complete calibration basis for the actual use of the sensor. The finally determined calibration equation, along with indicators such as linearity, hysteresis error, and repeatability error, should be recorded in the calibration report as a benchmark for converting the sensor to the actual pressure value during field use.

[0071] In some embodiments, after determining the pressure sensitivity coefficient and zero-point offset of the borehole radial stress gauge by data fitting based on the pressure values ​​at each level recorded during loading and unloading and the corresponding output signals, the method further includes: Repeatedly execute the loading and unloading process multiple times to obtain calibrated linearity and repeatability data.

[0072] After the initial loading and unloading cycle is completed and the calibration parameters are preliminarily determined, the calibration process continues into multiple cyclic loading and unloading phases to obtain sufficient data for evaluating the linearity and repeatability of the sensor output. The hydraulic pressurization system, following the same preset pressure gradient as the initial positive loading, gradually increases the pressure in the flexible hydraulic bladder from zero pressure or initial confining pressure to the rated maximum working pressure, and then gradually unloads it back to zero pressure, forming a complete loading and unloading cycle. The pressure stabilization criteria and data acquisition methods for each pressure level remain consistent with the initial loading phase to ensure the comparability of data between cycles.

[0073] After the pressure at each level stabilizes within each cycle, the data acquisition system synchronously records the current pressure value and the corresponding output reading of the stress gauge. Data from each cycle is stored independently and labeled with a cycle number for subsequent analysis by cycle or cross-cycle comparison. The number of cycles is determined based on the sensor's accuracy requirements and calibration specifications, typically no fewer than three effective cycles. The data from the first loading and unloading cycle can be included in the overall cyclic dataset for statistical analysis of linearity and repeatability, or it can be processed separately as pre-calibration data, depending on the specific design of the calibration scheme.

[0074] Linearity assessment is based on all calibration data collected during each cycle. After summing the output readings at each pressure level across all cycles, a new overall linear fit is performed using the least squares method to obtain a comprehensive calibration equation covering multiple cycles. Subsequently, the deviation between the measured output value at each calibration point and the predicted value of the comprehensive fitted line is calculated. The ratio of the maximum deviation over the entire range to the sensor's full-scale output value is taken as the linearity index, typically expressed as a percentage of full scale. The amount of data used for comprehensive fitting increases significantly due to multiple cycles, and the statistical stability of the fitting results is better than that obtained from a single loading calibration parameter.

[0075] Repeatability is assessed based on the degree of data dispersion between cycles. At the same pressure level, the sensor output readings are taken for each cycle, and the maximum deviation or standard deviation between these readings is calculated. After performing the above calculations for each pressure level across the full scale, the ratio of the maximum deviation to the full-scale output value is taken as the repeatability error index. Repeatability error reflects the fluctuation range of the sensor's output signal when the sensor is repeatedly loaded under the same pressure conditions. The smaller this value, the better the sensor's response consistency, and the higher the reliability of the calibration coefficient in actual use.

[0076] If the data at individual calibration points in a given cycle deviates significantly from those of other cycles, it is necessary to check whether this deviation is caused by abnormal factors during the pressurization process, such as insufficient pressure stabilization time, momentary poor contact of signal lines, or pressure fluctuations in the hydraulic system. Data points confirmed to be occasional anomalies can be removed from that cycle, but the remaining normal data points should be retained for continued statistical analysis. If the overall data of a given cycle deviates excessively from those of other cycles systematically, it is necessary to consider whether the deviation is due to abnormal equipment conditions. If necessary, the data from that cycle should be discarded and a new cycle should be executed.

[0077] After multiple cycles of loading and unloading are completed, the final linearity index and repeatability error, along with the pressure sensitivity coefficient, zero-point offset, and linear correlation coefficient obtained from the comprehensive fitting, are recorded in the calibration report as a complete technical basis for the traceability of the stress measurement value and on-site calibration.

[0078] In some embodiments, the method further includes: Generate a calibration report, which includes the original data, fitted curves, calibration coefficients, linearity index, and repeatability error index.

[0079] After all calibration data collection and fitting calculations are completed, the calibration report generation stage begins. The report first lists the basic information of the calibration operation, including the model and unique serial number of the stress gauge being calibrated, the calibration date, the serial number and rated working pressure range of the calibration device used, and the ambient temperature and humidity during calibration, providing a complete background record for the traceability and reproduction of the calibration results.

[0080] The core of the report is the complete presentation of the raw data. Using pressure as the independent variable and stress gauge output readings as the dependent variable, all pressure values ​​collected under each cycle and pressure level, along with their corresponding output readings, are listed and recorded sequentially according to the loading order. Each data point is labeled with its cycle number and loading or unloading stage, allowing reviewers to trace the source of the raw data upon which any fitted result is based. The raw data is presented without any rounding or truncation, preserving the original accuracy of the data acquisition system output.

[0081] Based on the original data, the report includes a fitted curve plot. This plot is a scatter plot with pressure values ​​on the horizontal axis and stress gauge output readings on the vertical axis, marking all calibration points collected in each cycle. The calibration line obtained from the least squares fitting is superimposed on the plot in the same coordinate system, making the deviation of each data point from the fitted line readily apparent. If loading and unloading fitting were performed separately, the loading and unloading fitted lines can be plotted separately in the graph; the distance between the two lines visually reflects the magnitude of the hysteresis characteristic.

[0082] The report then provides the numerical results of the calibration coefficients. The pressure sensitivity coefficient K is given as the slope of the fitted straight line, with its physical meaning and unit of measurement noted. The zero-point offset B is given as the intercept of the fitted straight line, reflecting the initial output deviation of the sensor under zero pressure. The linear correlation coefficient R² is also listed as a quantitative indicator of the fitting quality; the closer its value is to 1, the better the linear correspondence between the sensor output and the pressure. If separate fittings were performed for loading and unloading, the two sets of calibration coefficients are listed separately, along with the specific values ​​of the hysteresis error.

[0083] The linearity index is presented as a percentage of full scale in the report, indicating the pressure level at which the maximum linear deviation occurs and the magnitude of the deviation. The repeatability error index is also presented as a percentage of full scale, indicating the pressure level at which the maximum repeatability deviation occurs and the maximum dispersion range of the output readings for each cycle at that level. The calculation methods and judgment criteria for these indices are briefly explained in the report to facilitate user understanding of their statistical meaning.

[0084] The report concludes with a comprehensive assessment of the sensor's suitability. If all parameters, including pressure sensitivity coefficient, zero-point offset, linearity, repeatability error, and linear correlation coefficient, meet the relevant standards or technical requirements, the sensor is deemed calibrated successfully. The report will specify the validity period and applicable conditions of the calibration coefficients. If any parameter exceeds the allowable range, the report will indicate the non-compliance and its degree of deviation, allowing the client to decide whether recalibration is necessary.

[0085] It should be noted that the foregoing explanation of the method embodiments also applies to the apparatus of the embodiments of this disclosure, and the principle is the same. Therefore, the embodiments of this disclosure are not limited thereto.

[0086] According to embodiments of this disclosure, this disclosure also provides an electronic device, a readable storage medium, and a computer program product.

[0087] Figure 4 A schematic block diagram of an example electronic device 200 that can be used to implement embodiments of the present disclosure is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital assistants, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present disclosure described and / or claimed herein.

[0088] like Figure 4As shown, device 200 includes a computing unit 201, which can perform various appropriate actions and processes based on a computer program stored in ROM (Read-Only Memory) 202 or loaded from storage unit 208 into RAM (Random Access Memory) 203. RAM 203 may also store various programs and data required for the operation of device 200. The computing unit 201, ROM 202, and RAM 203 are interconnected via bus 204. I / O (Input / Output) interface 205 is also connected to bus 204.

[0089] Multiple components in device 200 are connected to I / O interface 205, including: input unit 206, such as keyboard, mouse, etc.; output unit 207, such as various types of monitors, speakers, etc.; storage unit 208, such as disk, optical disk, etc.; and communication unit 209, such as network card, modem, wireless transceiver, etc. Communication unit 209 allows device 200 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0090] The computing unit 201 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 201 include, but are not limited to, CPUs (Central Processing Units), GPUs (Graphics Processing Units), various special-purpose AI (Artificial Intelligence) computing chips, various computing units running machine learning model algorithms, DSPs (Digital Signal Processors), and any suitable processor, controller, microcontroller, etc. The computing unit 201 performs the various methods and processes described above, such as the method for calibrating a borehole radial stress gauge. For example, in some embodiments, the method for calibrating a borehole radial stress gauge may be implemented as a computer software program tangibly contained in a machine-readable medium, such as storage unit 208. In some embodiments, part or all of the computer program may be loaded and / or installed on device 200 via ROM 202 and / or communication unit 209. When the computer program is loaded into RAM 203 and executed by the computing unit 201, one or more steps of the methods described above may be performed. Alternatively, in other embodiments, the calculation unit 201 may be configured by any other suitable means (e.g., by means of firmware) to perform the aforementioned method of borehole radial stress gauge calibration.

[0091] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, FPGAs (Field Programmable Gate Arrays), ASICs (Application-Specific Integrated Circuits), ASSPs (Application-Specific Standard Products), SOCs (System-on-Chips), CPLDs (Complex Programmable Logic Devices), computer hardware, firmware, software, and / or combinations thereof. These various implementations may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0092] The program code used to implement the methods of this disclosure may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0093] In the context of this disclosure, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, RAM, ROM, EPROM (Electrically Programmable Read-Only Memory) or flash memory, optical fiber, CD-ROM (Compact Disc Read-Only Memory), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0094] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user (e.g., a CRT (Cathode-Ray Tube) or LCD (Liquid Crystal Display) monitor); and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the computer. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0095] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include LANs (Local Area Networks), WANs (Wide Area Networks), the Internet, and blockchain networks.

[0096] Computer systems can include clients and servers. Clients and servers are generally geographically separated and typically interact via communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. A server can be a cloud server, also known as a cloud computing server or cloud host, a hosting product within the cloud computing service system that addresses the shortcomings of traditional physical hosts and VPS (Virtual Private Server) services, such as high management difficulty and weak business scalability. Servers can also be servers for distributed systems or servers incorporating blockchain technology.

[0097] It's important to note that artificial intelligence (AI) is the study of enabling computers to simulate certain human thought processes and intelligent behaviors (such as learning, reasoning, thinking, and planning). It encompasses both hardware and software technologies. AI hardware technologies generally include sensors, dedicated AI chips, cloud computing, distributed storage, and big data processing. AI software technologies primarily include computer vision, speech recognition, natural language processing, machine learning / deep learning, big data processing, and knowledge graph technologies.

[0098] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this disclosure can be achieved, and this is not limited herein.

[0099] The specific embodiments described above do not constitute a limitation on the scope of protection of this disclosure. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A device for calibrating a borehole radial stress gauge, characterized in that, include: Rigid load-bearing frame; A flexible hydraulic bladder is disposed on the inner wall of the rigid pressure-bearing frame, and the interior of the flexible hydraulic bladder forms a closed hydraulic cavity. A hydraulic pressurization system, which is connected to the hydraulic chamber, is used to fill the hydraulic chamber with hydraulic medium and control the pressure inside the hydraulic chamber. The two end sealing assemblies are respectively disposed at both ends of the rigid pressure-bearing frame. Each end sealing assembly has a through hole through which the signal line of the borehole radial stress gauge passes and a sealing structure for sealing the through hole.

2. The apparatus according to claim 1, characterized in that, The rigid pressure-bearing frame is a segmented spliced ​​structure split along the axial direction, consisting of multiple arc-shaped segments connected by flanges and fasteners to form a cylindrical structure.

3. The apparatus according to claim 1, characterized in that, The flexible hydraulic bladder has a multi-layer composite structure, consisting of an inner sealing layer, a middle reinforcing layer, and an outer protective layer from the inside out.

4. The apparatus according to claim 1, characterized in that, Each of the end sealing assemblies has an annular positioning step on its inner side for axially positioning the borehole radial stress gauge to be calibrated within the rigid pressure-bearing frame.

5. The apparatus according to claim 1, characterized in that, The device also includes a data acquisition system, which is used to connect to the signal line of the borehole radial stress gauge to acquire and record the output signal of the borehole radial stress gauge under different confining pressures in real time.

6. A method for calibrating a borehole radial stress gauge, characterized in that, include: The borehole radial stress gauge to be calibrated is installed inside the flexible hydraulic bladder of the device, so that the central axis of the borehole radial stress gauge coincides with the axis of the device. The signal line is led out through the through hole of the end sealing assembly and sealed, and connected to the hydraulic pressurization system and the data acquisition system. An initial confining pressure is applied to the flexible hydraulic bladder through the hydraulic pressurization system, and the initial confining pressure is maintained for a preset time to expel residual gas in the system and test the sealing performance. Gradually increase the hydraulic pressure in the flexible hydraulic bladder to the rated maximum working pressure of the device. After each pressure level stabilizes, record the current pressure value and the corresponding output signal of the borehole radial stress gauge. After the loading is completed, the unloading is carried out in stages. During the unloading process, the output signal of the borehole radial stress gauge is recorded after the pressure of each stage stabilizes. Based on the pressure values ​​and corresponding output signals recorded during loading and unloading, the pressure sensitivity coefficient and zero-point offset of the borehole radial stress gauge are determined through data fitting.

7. The method according to claim 6, characterized in that, After determining the pressure sensitivity coefficient and zero-point offset of the borehole radial stress gauge through data fitting based on the pressure values ​​and corresponding output signals recorded during loading and unloading, the method further includes: Repeatedly execute the loading and unloading process multiple times to obtain calibrated linearity and repeatability data.

8. The method according to claim 6, characterized in that, The method further includes: Generate a calibration report, which includes the original data, fitted curves, calibration coefficients, linearity index, and repeatability error index.

9. An electronic device, characterized in that, include: At least one processor; as well as A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the method of any one of claims 6-8.

10. A non-transitory computer-readable storage medium storing computer instructions, characterized in that, The computer instructions are used to cause the computer to perform the method according to any one of claims 6-8.

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