A underground wall-stuck strain gauge

Abstract

The embodiment of the present application provides a downhole wall-stuck strain gauge, comprising an outer tube, a base, a measuring mechanism, a leveling mechanism and a capacitive displacement detection unit; the measuring mechanism comprises at least one pair of measuring rods arranged opposite to each other, the first ends of the two measuring rods are pivotally connected to the base, and the second ends of the two measuring rods are connected to the capacitive displacement detection unit through the leveling mechanism; the measuring drive unit is connected to one of the measuring rods through a first transmission member, and the measuring drive unit is connected to the other measuring rod through a second transmission member and a preloaded elastic member; the two measuring rods are respectively connected to the measuring arms; after the strain gauge is installed at a predetermined position, the measuring drive unit is actuated, and a preload force is applied to the measuring rod through the first transmission member and the second transmission member, and the measuring rod drives the measuring arm to extend out of the outer tube and clamp against the well wall; the leveling drive unit is actuated, and the strain gauge is adjusted to a zero position through the leveling rod. The strain gauge of the present application can realize strain observation downhole, which is convenient for maintenance.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of measurement technology, and in particular to an underground wall-stuck strain gauge. Background Art

[0002] Downhole strain gauges are important instruments for downhole strain observation. They can be used independently or deployed underground with other observation instruments to achieve downhole observation. At present, downhole strain gauges mainly use cement consolidation installation and the principle of measuring instrument sealing tube inner diameter change to achieve downhole strain observation. The cement consolidation installation method has the problem of being unrepairable. Once the instrument fails, it may cause all instruments to stop working, and the entire well will become an abandoned well, affecting the utilization efficiency of downhole instruments and causing huge economic losses. Summary of the invention

[0003] In view of this, an object of an embodiment of the present application is to provide a downhole wall-stuck strain gauge to solve the maintainability problem of the downhole strain gauge.

[0004] Based on the above purpose, the embodiment of the present application provides a downhole wall-stuck strain gauge, including: an outer cylinder, a base, a measuring mechanism, a leveling mechanism and a capacitive displacement detection unit;

[0005] The outer cylinder and the base are fixedly connected via a support column, and the outer cylinder is fixedly connected to the measurement drive unit via a drive support column;

[0006] The measuring mechanism comprises at least one pair of measuring rods arranged opposite to each other, the first ends of the two measuring rods are pivotally connected to the base, and the second ends of the two measuring rods are connected to the capacitive displacement detection unit through the leveling mechanism; the measuring drive unit is connected to one of the measuring rods through a first transmission member, and the measuring drive unit is connected to the other measuring rod through a second transmission member and a preloaded elastic member; the two measuring rods are respectively connected to measuring arms, and the positions of the measuring arms and the outer cylinder correspond;

[0007] The leveling mechanism comprises a leveling drive unit and a leveling rod, wherein the second end of one measuring rod is fixedly connected to the leveling drive unit, the output shaft of the leveling drive unit is connected to the fixed electrode plate of the capacitive displacement detection unit through the leveling rod, and the second end of the other measuring rod is connected to two moving electrode plates of the capacitive displacement detection unit;

[0008] After the strain gauge is installed in the predetermined position, the measuring drive unit is activated to apply a preload force to the two measuring rods through the first transmission member and the second transmission member, and the two measuring rods drive the measuring arms to extend out of the outer tube and abut against the well wall; the leveling drive unit is activated to adjust the relative positions of the fixed electrode plate and the two moving electrode plates through the leveling rod, so that the strain gauge is in a zero position state.

[0009] Optionally, during the measurement of the strain gauge, when the well wall is deformed, the other measuring rod changes position under the action of the preload elastic member, the two moving electrodes change position, and the capacitive displacement detection unit converts the position change of the two moving electrodes into a corresponding electrical signal.

[0010] Optionally, the measuring drive unit moves in the reverse direction, applying a pulling force to the two measuring rods through the first transmission member and the second transmission member, and the two measuring rods drive the measuring arms to retract.

[0011] Optionally, the first end of the leveling rod is connected to the output shaft of the leveling drive unit, the second end of the leveling rod is movably connected to the fixed electrode plate through a first fixed plate, and the second end of the other measuring rod is fixedly connected to the two moving electrode plates through a second fixed plate.

[0012] Optionally, a limiting spring is provided between the first fixing plate and the second fixing plate.

[0013] Optionally, a limiting portion is provided at the first end of the leveling rod, and the output shaft of the leveling drive unit is connected to the leveling rod via the limiting portion.

[0014] Optionally, the measuring mechanism includes two groups, one group is arranged along a first direction, and the other group is arranged along a second direction, and the first direction is perpendicular to the second direction.

[0015] Optionally, the measuring drive unit is connected to the other measuring rod via the second transmission member, a supporting driving rod, and a preload spring.

[0016] Optionally, the measuring rod is fixedly connected to the measuring arm via a connecting block.

[0017] Optionally, the capacitive displacement detection unit is connected to a ground host via a signal detection unit, and the electrical signal is amplified, phase-sensitively detected, and integrated and amplified by the signal detection unit before being transmitted to the ground host.

[0018] From the above description, it can be seen that the downhole wall-engaging strain gauge provided in the embodiment of the present application includes an outer cylinder, a base, a measuring mechanism, a leveling mechanism and a capacitive displacement detection unit, etc.; the measuring mechanism includes at least one pair of measuring rods arranged opposite to each other, and the two measuring rods are respectively connected to the measuring arms. By extending the measuring arms until they are engaged with the well wall, the deformation of the well wall can be detected by the measuring arms, thereby realizing downhole strain observation. By retracting the measuring arms, the strain gauge can be taken out as a whole, which is convenient for maintenance of the instrument, easy to operate and use, and improves the utilization rate of the instrument. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 This is a schematic diagram of the three-dimensional structure of an embodiment of the present application, in which the measuring arm is not extended;

[0021] Figure 2 It is a partial structural schematic diagram of an embodiment of the present application;

[0022] Figure 3 It is a schematic diagram of the three-dimensional structure of another embodiment of the present application, with the measuring arm extended;

[0023] Figure 4 This is a schematic diagram of a three-dimensional structure of another embodiment of the present application;

[0024] Figure 5 This is a schematic diagram of the planar structure of an embodiment of the present application, in which the measuring arm is not extended;

[0025] Figure 6 This is a schematic diagram of the planar structure of another embodiment of the present application, with the measuring arm extended;

[0026] Figure 7 This is a schematic diagram of the connection structure between the measuring rod and the measuring arm of an embodiment of the present application;

[0027] Figure 8 A schematic diagram of the measurement direction of an embodiment of the present application;

[0028] Fig. 9 Schematic diagram of the signal detection principle of an embodiment of the present application. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0030] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should be the usual meanings understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the embodiments of the present application do not represent any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing in front of the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connecting" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to represent relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0031] like Figure 1-6 As shown, the embodiment of the present application provides a downhole wall-stuck strain gauge, including an outer tube 1, a base 2, a measuring mechanism and a leveling mechanism;

[0032] The outer cylinder 1 and the base 2 are fixedly connected via a support column 3, and the outer cylinder 1 is fixedly connected to a measurement drive unit 4 via a drive support column;

[0033] The measuring mechanism comprises at least one pair of measuring rods 5 arranged opposite to each other, the first ends of the two measuring rods are pivotally connected to the base 2, and the second ends of the two measuring rods are connected to the capacitive displacement detection unit through the leveling mechanism; the measuring drive unit 4 is connected to one of the measuring rods through the first transmission member, and the measuring drive unit 4 is connected to the other measuring rod through the second transmission member and the preload elastic member; the two measuring rods are respectively connected to the measuring arms 501, and the measuring arms 501 correspond to the positions of the outer cylinder 1;

[0034] The leveling mechanism includes a leveling drive unit 7 and a leveling rod 6, wherein the second end of one measuring rod is fixedly connected to the leveling drive unit 7, the output shaft of the leveling drive unit 7 is connected to the fixed electrode plate of the capacitive displacement detection unit through the leveling rod 6, and the second end of the other measuring rod is connected to the two moving electrode plates of the capacitive displacement detection unit;

[0035] After the strain gauge is installed in the predetermined position, the measuring drive unit 4 is activated to apply a preload force to the two measuring rods through the first transmission member and the second transmission member. The two measuring rods drive the measuring arm 501 to extend out of the outer tube 1 and abut against the well wall. The leveling drive unit 7 is activated to adjust the relative positions of the fixed electrode plate and the two moving electrode plates through the leveling rod 6 so that the strain gauge is in a zero position state.

[0036] The present embodiment provides a downhole clamp-arm strain gauge, including an outer tube 1, a base 2, a measuring mechanism and a leveling mechanism. The outer tube 1 and the base 2 are fixedly connected by four support columns 3 to stably support the instrument. The outer tube 1 is fixedly connected to the measuring drive unit 4 through the driving support column, and the measuring drive unit 4 is used to provide driving force for the measuring mechanism. The measuring mechanism includes at least one pair of measuring rods 5 arranged opposite to each other, and the shapes of the two measuring rods 5 are symmetrical; the first ends of the two measuring rods are pivotally connected to the base 2 and can rotate relative to the base, and the second ends of the two measuring rods are connected to the capacitive displacement detection unit through the leveling mechanism. The relative position of the moving electrode plate and the fixed electrode plate of the capacitive displacement detection unit can be adjusted by the leveling mechanism. In the initial working state, the strain gauge is adjusted to the zero position state.

[0037] The measuring drive unit 4 is connected to one of the measuring rods 51 through the first transmission member 8, and is connected to the other measuring rod 52 through the second transmission member 9 and the preload elastic member 10. When the strain gauge is installed at a predetermined position underground, the measuring drive unit 4 is controlled to operate, and driven by the measuring drive unit 4, the first transmission member 8 and the second transmission member 9 operate to apply a preload force toward the well wall to the measuring rods 51 and 52. In other words, the measuring drive unit 4 pushes the measuring rods 51 and 52 toward the well wall through the first transmission rod 8 and the second transmission rod 9, and the measuring rods 51 and 52 drive the measuring arm 501 to operate toward the well wall, and the measuring arm 501 extends out of the outer tube 1 and is stuck against the well wall.

[0038] In some embodiments, the measuring drive unit 4 is connected to the measuring rod 52 through the second transmission member 9, the supporting driving rod 13, and the preload spring. One end of the supporting driving rod 13 is connected to the second transmission column 9, the other end of the supporting driving rod 13 is pivotally connected to the base 2, the concave portion of the supporting driving rod 13 is connected to one end of the preload spring, and the other end of the preload spring is in contact with the measuring rod 52, so that the space utilization is reasonable.

[0039] The leveling mechanism includes a leveling drive unit 7 and a leveling rod 6, the second end of the measuring rod 51 is fixedly connected to the leveling drive unit 7, the output shaft of the leveling drive unit 7 is connected to the fixed electrode plate 101 of the capacitive displacement detection unit through the leveling rod 6, and the second end of the measuring rod 52 is connected to the two moving electrode plates 102 of the capacitive displacement detection unit; the fixed electrode plate 101 is located between the two moving electrode plates 102, when the fixed electrode plate 101 and the two moving electrode plates 102 are parallel to each other, and the distance from the fixed electrode plate to one of the moving electrode plates is equal to the distance from the fixed electrode plate to the other moving electrode plate, that is, the capacitance value formed between the fixed electrode plate 101 and one of the moving electrode plates is equal to the capacitance value formed between the fixed electrode plate 101 and the other moving electrode plate, the strain gauge is in a zero position state.

[0040] When the strain gauge is installed at a predetermined position underground and a preload is applied to the two measuring rods through the measuring drive unit 4, after the measuring arm 501 is stuck against the well wall, the leveling drive unit 7 is controlled to operate, and the output shaft of the leveling drive unit 7 operates, driving the leveling rod 6 to operate, and the leveling rod 6 drives the fixed electrode plate 101 to change its position, adjusting the fixed electrode plate 101 to the middle position between the two moving electrode plates 102, and then adjusting the strain gauge to the initial working zero position state.

[0041] In some embodiments, during the measurement process of the strain gauge, when the well wall is deformed, the measuring rod 52 changes position under the action of the preloaded elastic member 10, and the two moving electrode plates 102 change position. The capacitive displacement detection unit converts the position change of the two moving electrode plates into a corresponding electrical signal to achieve strain detection in the well. In this embodiment, after the strain gauge is installed at a predetermined position and adjusted to an initial working state, the strain gauge starts measuring. When the well wall is deformed, the measuring rod 51 does not change position under the preloaded force of the first transmission member 8. The measuring rod 52 changes position accordingly with the deformation of the well wall under the elastic force of the preloaded elastic member 10. The position change of the measuring rod 52 drives the moving electrode plate 102 to change position accordingly, and the capacitance value formed between the fixed electrode plate 101 and the two moving electrode plates 102 changes. Then, the capacitive displacement detection unit converts the deformation of the well wall into a corresponding electrical signal to achieve strain detection in the well.

[0042] In some embodiments, the measuring drive unit moves in the reverse direction, applies tension to the two measuring rods through the first transmission member 8 and the second transmission member 9, and the two measuring rods drive the measuring arm 501 to retract. In this embodiment, when the strain gauge needs maintenance or redeployment, the measuring drive unit 4 is controlled to move in the reverse direction, and the reverse movement of the measuring drive unit drives the first transmission member 8 and the second transmission member 9 to move in the reverse direction, pulling the two measuring rods 51 and 52 in the opposite direction of the well wall. The two measuring rods are pulled back to the outer tube 1 by the tension, and after the measuring arm 501 is retracted, the strain gauge can be taken out from the well as a whole. In this way, by using the downhole wall-stuck strain gauge provided by the present application, the deformation of the well wall can be detected by the measuring arm by extending the measuring arm until it is stuck with the well wall, and the strain gauge can be taken out as a whole by retracting the measuring arm, which is convenient for maintenance of the instrument, operation and use, and improves the utilization rate of the instrument.

[0043] In some embodiments, the first end of the leveling rod 6 is connected to the output shaft of the leveling drive unit 7, the second end of the leveling rod 6 is movably connected to the fixed electrode plate 101 through the first fixed plate 11, and the second end of the measuring rod 52 is fixedly connected to the two moving electrode plates 102 through the second fixed plate 12. Specifically, the second end of the measuring rod 51 is fixedly connected to the leveling drive unit 7, the output shaft of the leveling drive unit 7 is connected to the first end of the leveling rod 6, the second end of the leveling rod 6 is pivotally connected to the upper end of the first fixed plate 11, the first fixed plate 11 can rotate within a certain range relative to the leveling rod 6, and the lower end of the first fixed plate 11 is fixedly connected to the fixed electrode plate 101. The leveling drive unit 7 is actuated to drive the leveling rod 6 to move up and down, and the up and down movement of the leveling rod 6 drives the first fixed plate 11 to rotate, and the first fixed plate 11 changes the position of the fixed electrode plate 101 between the two moving electrode plates 102 during the rotation process.

[0044] In some embodiments, a limit spring 14 is provided between the first fixing plate 11 and the second fixing plate 12. By providing the limit spring 14 between the first fixing plate 11 and the second fixing plate 12 and on both sides of the moving electrode plate and the fixed electrode plate, the relative position adjustment range of the fixed electrode plate and the moving electrode plate can be limited, the measurement accuracy can be improved, and the instrument can be prevented from being damaged.

[0045] like Figure 4 As shown, in some embodiments, a limiting portion 61 is provided at the first end of the leveling rod 6, and the output shaft of the leveling drive unit 7 is connected to the leveling rod 6 via the limiting portion, which can limit the position adjustment range of the fixed pole plate.

[0046] In some embodiments, the strain gauge includes two groups of measuring mechanisms, one group of measuring mechanisms is arranged along a first direction, and the other group of measuring mechanisms is arranged along a second direction, and the first direction is perpendicular to the second direction. Figure 8 As shown, the strain gauge can be configured with two groups of measuring mechanisms, wherein the two measuring arms 501A of one group of measuring mechanisms are used to measure the strain in the first direction, and the two measuring arms 501B of the other group of measuring mechanisms are used to measure the strain in the second direction. In practical applications, in order to measure the strain in multiple directions, multiple strain gauges can be arranged in sequence up and down along the axial direction of the drilling, and the measuring mechanisms of each strain gauge are arranged along the direction to be measured. For example, the two groups of measuring mechanisms of one strain gauge can measure the strain in the east-west direction and the north-south direction, and the two groups of measuring mechanisms of the other strain gauge can measure the strain in the northeast, southwest direction and the southeast, northwest direction; the above is only an exemplary description, and the specific deployment method of the strain gauge is not limited.

[0047] like Figure 7As shown, in some embodiments, the measuring rod and the measuring arm are fixedly connected by mortise and tenon, which is stable and reliable. In some embodiments, the measuring rod 5 is fixedly connected to the measuring arm 501 by the connecting block 15, which can ensure that there is a certain degree of freedom between the measuring rod 5 and the measuring arm 501, and facilitate assembly. The measuring arm 501 is a cylindrical component, and the measuring arm is connected to the outer cylinder 1 by a guide 16, which can ensure that the measuring arm is smoothly extended and retracted, and the contact surface between the measuring arm and the outer cylinder 1 has a waterproof sealing effect.

[0048] In some embodiments, the strain gauge further includes a protective tube, which is consistent with the outer diameter of the outer tube 1, so as to facilitate the lowering and removal of the strain gauge as a whole, protect the internal components, and have a waterproof function. The overall structure of the strain gauge can be adaptively designed according to the aperture size of the well.

[0049] like Fig. 9 As shown, in some embodiments, the capacitance displacement detection unit is connected to the ground host through the signal detection unit, and the signal detection unit includes a signal amplifier, a phase-sensitive detector, an integral amplifier, etc. The electrical signal detected by the capacitance displacement detection unit is amplified by the signal detection unit, subjected to phase-sensitive detection processing, and integral amplification processing, and then transmitted to the ground host. This embodiment does not explain in detail the circuit structure and principle of the signal detection unit.

[0050] The downhole wall-clamping strain gauge provided in the embodiment of the present application comprises two measuring rods arranged in the measuring direction, and the measuring rods are provided with measuring arms that can be extended or retracted. After the strain gauge is installed at a predetermined position downhole, the measuring arm is extended and clamped against the well wall, and the instrument is adjusted to the zero position state of initial operation. During the measurement process of the instrument, the measuring arm is used to detect the deformation amount of the well wall to realize the strain observation downhole; when the strain gauge needs maintenance, the measuring arm is retracted to facilitate the removal of the instrument as a whole, and the installation, use and maintenance are convenient, and the structure is simple and the design is reasonable.

[0051] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present disclosure (including the claims) is limited to these examples. Based on the concept of the present disclosure, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0052] In addition, to simplify the description and discussion, and in order not to make the embodiments of the present application difficult to understand, the known power supply / ground connection with the integrated circuit (IC) chip and other components may or may not be shown in the provided drawings. In addition, the device can be shown in the form of a block diagram to avoid making the embodiments of the present application difficult to understand, and this also takes into account the fact that the details of the implementation of these block diagram devices are highly dependent on the platform to be implemented in the embodiments of the present application (that is, these details should be fully within the scope of understanding of those skilled in the art). In the case of elaborating specific details (e.g., circuits) to describe exemplary embodiments of the present disclosure, it is obvious to those skilled in the art that the embodiments of the present application can be implemented without these specific details or when these specific details are changed. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0053] Although the present disclosure has been described in conjunction with specific embodiments of the present disclosure, many replacements, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may use the embodiments discussed.

[0054] The embodiments of the present application are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present application should be included in the scope of protection of the present disclosure.

Claims

1. A downhole wall-stuck strain gauge, characterized in that: include: An outer cylinder, a base, a measuring mechanism, a leveling mechanism and a capacitive displacement detection unit; The outer cylinder and the base are fixedly connected via a support column, and the outer cylinder is fixedly connected to the measurement drive unit via a drive support column; The measuring mechanism comprises at least one pair of measuring rods arranged opposite to each other, the two measuring rods are symmetrical in shape, the first ends of the two measuring rods are pivotally connected to the base, and the second ends of the two measuring rods are connected to the capacitive displacement detection unit through the leveling mechanism; the measuring drive unit is connected to one of the measuring rods through a first transmission member, and the measuring drive unit is connected to the other measuring rod through a second transmission member, a support drive rod, and a preload elastic member, one end of the support drive rod is connected to the second transmission member, the other end of the support drive rod is pivotally connected to the base, the recess of the support drive rod is connected to one end of the preload spring, and the other end of the preload spring abuts against the measuring rod; the two measuring rods are respectively connected to measuring arms for detecting the deformation of the well wall, the measuring arms correspond to the positions of the outer cylinder, the outer cylinder is provided with an opening corresponding to the measuring arms, the measuring arms are connected to the outer cylinder by a guide member to ensure that the measuring arms are smoothly extended and retracted, and the contact surface between the measuring arms and the outer cylinder is waterproof and sealed; The leveling mechanism comprises a leveling drive unit and a leveling rod, wherein the second end of one measuring rod is fixedly connected to the leveling drive unit, the output shaft of the leveling drive unit is connected to the first end of the leveling rod, the second end of the leveling rod is movably connected to the fixed electrode plate of the capacitive displacement detection unit through a first fixed plate, the second end of the other measuring rod is fixedly connected to two moving electrode plates of the capacitive displacement detection unit through a second fixed plate, the fixed electrode plate is located between the two moving electrode plates, when the fixed electrode plate and the two moving electrode plates are parallel to each other, and the distance from the fixed electrode plate to one of the moving electrode plates is equal to the distance from the fixed electrode plate to the other moving electrode plate, the strain gauge is in a zero position state; a limit spring is provided between the first fixed plate and the second fixed plate; After the strain gauge is installed at the predetermined position, the measuring drive unit is activated to apply pre-tightening force to the two measuring rods through the first transmission member and the second transmission member, and the two measuring rods drive the measuring arms to extend out of the outer cylinder and clamp against the well wall; the leveling drive unit is activated to adjust the relative positions of the fixed electrode plate and the two moving electrode plates through the leveling rod, so that the strain gauge is in a zero position state; During the measurement process of the strain gauge, when the well wall is deformed, one of the measuring rods does not change position under the action of the preload force of the first transmission member, the other measuring rod changes position under the action of the preload elastic member, the two moving plates change position, and the capacitive displacement detection unit converts the position change of the two moving plates into a corresponding electrical signal; The measuring drive unit moves in the reverse direction, applying a pulling force to the two measuring rods through the first transmission member and the second transmission member, and the two measuring rods drive the measuring arms to retract.

2. The strain gauge according to claim 1, characterized in that A limiting portion is provided at the first end of the leveling rod, and the output shaft of the leveling drive unit is connected to the leveling rod via the limiting portion.

3. The strain gauge according to claim 1, characterized in that The measuring mechanism comprises two groups, one of which is arranged along a first direction, and the other is arranged along a second direction, and the first direction is perpendicular to the second direction.

4. The strain gauge according to claim 1, characterized in that The measuring rod is fixedly connected to the measuring arm via a connecting block.

5. The strain gauge according to claim 1, characterized in that The capacitive displacement detection unit is connected to the ground host through the signal detection unit, and the electrical signal is amplified, phase-sensitively detected, and integrated and amplified by the signal detection unit before being transmitted to the ground host.

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