A micropore depth measuring device and method

Abstract

The present application belongs to the technical field of metal micropore measurement, and particularly relates to a nondestructive metal material micropore depth measurement device and method. A flexible probe is carried on a three-dimensional moving platform. The probe has a small diameter, elasticity, multiple length specifications, low loss rate and long service life, and can measure pores with different depths. The three-dimensional moving platform is driven by a piezoelectric ceramic motor, has a small minimum step length and high measurement accuracy. During measurement, a positioning camera and an LED lamp arranged on the probe are used to preliminarily judge the position and internal form of the micropore, so that the pore depth can be more accurately measured. The measurement process is nondestructive detection, and is performed in a vacuum environment to reduce the influence of air dust on the test result, avoid or reduce the damage of tip discharge to the surface of the measured sample, replace the probe with different specifications according to the pore depth, and measure the pore depth of the measured sample with different specifications and shapes, especially the pores with small width-depth ratio generated by corrosion.

Description

Technical fields:

[0001] This invention belongs to the field of metal micropore measurement technology, specifically relating to a non-destructive device and method for measuring the depth of micropores in metal materials, which can measure the depth of corrosion holes with a large width-to-depth ratio. Background technology:

[0002] Existing methods for measuring the depth of micropores can be broadly categorized into two types: the first type involves physical contact methods, using tools such as vernier calipers or digital calipers for larger pores and devices with pointed tips, such as corrosion pit depth gauges, for smaller pores; the second type involves non-contact optical methods, using laser light sources and cameras to find the focal point, or using ultra-depth-of-field cameras to capture three-dimensional morphology frame by frame, or using ultrasonic flaw detection. For example, Chinese Patent 202310018581 discloses a method for measuring the depth of blind holes in a blind hole plate, applied to a processor in a blind hole plate optical inspection system. The blind hole plate optical inspection system includes multiple 3D cameras and a processor. The method includes: scanning a target blind hole plate using the multiple 3D cameras to obtain 3D image data of the target blind hole plate; acquiring prior information about the target blind hole plate, including through-hole coordinates on the target blind hole plate data; determining through-hole coordinates in the 3D image data based on the through-hole coordinates on the target blind hole plate data; determining blind hole coordinates in the 3D image data based on the through-hole coordinates in the 3D image data; determining a blind hole rectangle based on the blind hole coordinates in the 3D image data; obtaining calculation points within the range of the blind hole rectangle; and calculating the depth of the blind hole corresponding to the blind hole rectangle based on the depth information of the calculation points in the 3D image data. Chinese Patent 202223007879 discloses a hole depth measuring device, comprising a base plate, a U-shaped plate, a winding drum rotatably mounted on the U-shaped plate, and a graduated rope wound on the winding drum. A damping magnetic attraction assembly is installed between the winding drum and the U-shaped plate. Support rods are symmetrically connected between the bottom of the U-shaped plate and the top of the base plate. Guide sleeves are slidably sleeved on the support rods. A crossbar is connected between the guide sleeves. A spool for the graduated rope to pass through is embedded in the center of the crossbar. A pendant is connected to the bottom end of the graduated rope, and a pressing and positioning assembly is installed between the graduated rope and the spool. Chinese Patent 202222818716 discloses a hole depth measuring device, comprising a measuring base, a measuring gauge mounted on the measuring base, a measuring shaft, a compression spring disposed between the measuring gauge and the measuring shaft, and an anti-detachment mechanism for limiting the measuring shaft. The measuring gauge is mounted on the measuring base via a fastening set screw. The compression spring is fitted onto the measuring rod of the measuring gauge, with its lower end acting on the measuring shaft. The anti-detachment mechanism includes a limiting set screw and a limiting groove. The measuring base is provided with an upper set screw hole for mounting the fastening set screw, a lower set screw hole for mounting the limiting set screw, and an axial through hole. The axial through hole includes a gauge mounting hole for mounting the measuring gauge and a shaft mounting hole for mounting the measuring shaft. The limiting groove is disposed on the surface of the measuring shaft, and the inner end of the limiting set screw passes through the lower set screw hole and acts on the limiting groove.Chinese Patent 202222517399 discloses a borehole depth measuring device for rock and soil geological exploration, comprising a transport platform, a support frame fixedly connected to the top of the transport platform, a measuring tape shaft rotatably connected to the middle of the top of the support frame, a handle fixedly connected to one end of the measuring tape shaft, a measuring tape wound around the outer wall of the measuring tape shaft, a placement cage fixedly connected to one end of the measuring tape, an indicator light and a horn fixedly connected to both sides of the top surface of the placement cage, a base threadedly connected to the bottom of the placement cage, a battery fixedly connected to the top of the base, and three microswitches fixedly connected to the bottom of the base. Chinese Patent 202210723311 discloses a device for measuring the hole depth of automotive parts, including a probe shaft, an ultrasonic transmitting array device, and an ultrasonic receiving array device. Both the ultrasonic transmitting array device and the ultrasonic receiving array device are fixed to the right end of the probe shaft. The device also includes a first differential twisted pair cable, a second differential twisted pair cable, and a handle bracket. The first and second differential twisted pair cables are connected by a third differential twisted pair cable. The third differential twisted pair cable is intermittently wound around a spring inside the handle bracket. The end of the first differential twisted pair cable away from the third differential twisted pair cable connects to the ultrasonic transmitting array device and the receiving array device. An ultrasonic receiving array device is led out, and a transducer is fixedly connected to the end of the second differential twisted pair away from the third differential twisted pair. The output end of the transducer is connected to the input end of the human-machine interface. The input end of the transducer and the human-machine interface are connected to the output end of the computer controller through wires. The probe shaft is slidably connected to the handle frame through a sliding bracket. A sliding strip opening is provided on the handle frame, and a toggle block is slidably connected in the sliding strip opening. The toggle block is fixedly connected to the sliding bracket. Multiple ring groove groups are provided on the right end of the handle frame. Each ring groove group includes multiple mounting slots, and a telescopic rod is connected in each of the multiple mounting slots through a flexible spring.

[0003] The aforementioned patents involve measuring devices or methods that suffer from limitations in measuring deep, small-diameter holes, or that produce poor measurement results. Specifically, when the hole diameter is too small, the test contacts of physical contact measuring devices cannot properly extend into the hole; when ultra-depth-of-field cameras capture images of deep, relatively closed holes, the image inside the hole is prone to distortion, making the hole appear as a "bulge," and the smaller the aspect ratio of the hole, the more pronounced the distortion; ultrasonic testing has low resolution. Therefore, it is essential to develop and design a depth measuring device and method for micropores in metallic materials, especially those with small aspect ratios. Summary of the Invention:

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and to develop and design a micropore depth measuring device and its usage method. It adopts a non-destructive measurement method to measure the depth of holes with a small width-to-depth ratio, especially micropores caused by metal corrosion.

[0005] To achieve the above objectives, the main structure of the micropore depth measuring device of the present invention includes a vacuum chamber and a measuring platform disposed therein; the main structure of the vacuum chamber includes a door and a chamber connected to each other; the main structure of the measuring platform includes a measuring platform base and a three-dimensional moving platform and a sample stage disposed thereon, as well as a probe disposed on the three-dimensional moving platform.

[0006] The hatch and compartment involved in this invention are connected by two sliding shafts. One end of the sliding shaft is fixedly connected to the bottom of the hatch, and the other end extends into the base of the compartment and slides. The three-dimensional moving platform is composed of a three-dimensional moving platform base, an X-axis motor base, an X-axis motor drive plate, a Y-axis motor base, a Y-axis motor drive plate, a stiffener, a Z-axis motor base, a Z-axis motor drive plate, and a motor, which drive the probe to move in the X, Y, and Z axis directions. The sample stage is used to mount the measurement sample.

[0007] The micropore depth measuring device of this invention is connected to control software during measurement. The control software causes the probe to make micro-movements in the X and Y axes during its descent to probe the edge position of the micropore sidewall of the sample. The Z-value is measured under different XY coordinates to obtain the value of the deepest point of the micropore. Specifically, a set pulse voltage is applied between the sample and the probe, and the instantaneous micro-current between them is detected. When the distance between the probe and the bottom of the micropore approaches a set value, a tip discharge occurs between the sample and the probe. The control software detects this instantaneous micro-current, and simultaneously, the three-dimensional moving platform stops moving, recording the depth in the Z-axis direction. The pulse voltage is then reduced by the control software, and the probe continues to descend in the Z-axis direction at a low speed until the control software detects the instantaneous micro-current again, at which point the three-dimensional moving platform stops moving. This process continues until the probe's descent completely stops at a certain pulse voltage. At this point, the relative depth in the Z-axis direction is the pore depth of the sample.

[0008] The micro-hole depth measuring device of this invention is suitable for open holes with a large width-to-depth ratio and a large diameter. The positioning camera on the probe accurately determines the bottom position of the hole, and the probe moves along the Z-axis according to the selected position to obtain the accurate hole depth. When the width-to-depth ratio is small and the hole diameter is small, the positioning camera finds the position of the micro-hole, and the probe moves along the spiral trajectory and moves down the inner wall surface of the hole in a spiral manner to measure, ensuring the accuracy of the measurement results and greatly shortening the hole depth measurement time.

[0009] Compared with existing technologies, this invention mounts a flexible probe on a three-dimensional moving platform. The probe has a small diameter, is elastic, and comes in various length specifications, resulting in low wear and long service life. It can measure holes of different depths. The three-dimensional moving platform is driven by a piezoelectric ceramic motor, with a small minimum step size and high measurement accuracy. During measurement, a positioning camera and LED light on the probe are used to make a preliminary judgment on the position and internal morphology of the micropore, so as to more accurately measure the hole depth. The measurement process is non-destructive testing and is carried out in a vacuum environment to reduce the influence of airborne dust on the test results and avoid or reduce the damage of the sample surface to the measured sample by tip discharge. By changing the probe of different specifications according to the hole depth, the hole depth of the measured sample of different shapes and sizes can be measured, especially for holes with a small width-to-depth ratio caused by corrosion. Its application range is wider, and the measurement accuracy and automation level are higher. Through programming and software control, the measurement is carried out in a vacuum without contacting the sample surface, making the measurement process more convenient. Attached image description:

[0010] Figure 1 This is a schematic diagram of the main structure of the micropore depth measuring device involved in this invention.

[0011] Figure 2 This is a schematic diagram of the main structure of the vacuum chamber involved in this invention.

[0012] Figure 3 This is a schematic diagram of the bottom of the main structure of the vacuum chamber involved in this invention.

[0013] Figure 4 This is a schematic diagram of the back of the main structure of the vacuum chamber involved in this invention.

[0014] Figure 5 This is a schematic diagram of the main structure of the measurement platform involved in this invention.

[0015] Figure 6 This is a partial schematic diagram of the main structure of the measurement platform involved in the present invention.

[0016] Figure 7 This is a schematic diagram illustrating the connection relationship between the probe connecting shaft slot and the probe connecting shaft involved in this invention.

[0017] Figure 8 This is a schematic diagram illustrating the connection relationship between the probe connecting shaft and the probe involved in the present invention.

[0018] Figure 9 This is a schematic diagram showing the connection relationship when the micropore depth measuring device of the present invention is in use.

[0019] Figure 10 This is a schematic diagram of the pulse voltage-time curve involved in the present invention.

[0020] Figure 11This is a schematic diagram of the trajectory of the probe involved in this invention. Detailed implementation method:

[0021] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0022] Example 1:

[0023] The main structure of the micropore depth measuring device involved in this example includes a vacuum chamber 1 and a measuring platform 2 installed inside the vacuum chamber 1. The main structure of the vacuum chamber 1 includes a door 101 and a chamber 102 connected by two sliding shafts 103. One end of the sliding shaft 103 is fixedly connected to the bottom of the door 101, and the other end extends into the base 104 of the chamber 102 and slides. The door 1 has an observation window 105 and a handle 106 on the front, a load-bearing wheel 107 on the bottom, and a loading plate 108 on the inner side. The top of the chamber 102 is equipped with a camera 109, and the bottom is equipped with several arrays. The load-bearing wheels 110 of the arranged loading platform have exhaust connection holes 111 and signal and line wiring holes 112 on the back; the main structure of the measuring platform 2 includes a measuring platform base 201, a leveling knob 202, a positioning hole 203, a sample stage 204, a three-dimensional moving platform base 205, a sample clamp 206, a wire 207, an X-axis motor base 208, an X-axis motor drive plate 209, a Y-axis motor base 210, a Y-axis motor drive plate 211, a stiffener 212, a Z-axis motor base 213, a Z-axis motor drive plate 214, and a motor 215, which is a piezoelectric ceramic motor. The components include a probe mounting base 216, a probe connecting shaft slot 217, a wiring integrator 218, an electrical signal integrator 219, a locking button 220, a pop-out button 221, a probe connecting shaft 222, a spring 223, a wire hole 224, a positioning groove 225, a probe 226, a connection port 227, an LED light 228, a positioning camera 229, and a needle tip 230. The measuring platform base 201 has leveling knobs 202 at its four bottom corners and several equally spaced positioning holes 203 on its two top sides. The sample stage 204 and the three-dimensional moving platform base 205 are connected according to the set requirements via corresponding... Positioning holes 203 are provided on the measurement platform base 201; a sample clamp 206 for holding the measurement sample 10 is provided on the sample stage 204, and a wire 207 is provided at the tail end of the sample clamp 206; from bottom to top, the three-dimensional moving platform base 205 is provided with an X-axis motor base 208, an X-axis motor drive plate 209, a Y-axis motor base 210, a Y-axis motor drive plate 211, a rib plate 212, a Z-axis motor base 213, and a Z-axis motor drive plate 214, and motors 215 are provided on the X-axis motor drive plate 209, the Y-axis motor drive plate 211, and the Z-axis motor drive plate 214;The Z-axis motor drive board 214 is connected to the probe connecting shaft slot 217 via the probe mounting base 216. The probe connecting shaft slot 217 has a wiring integrator 218 and an electrical signal integrator 219 on its top, a locking button 220 on its side, a pop-out button 221 on its bottom, and connects to the probe connecting shaft 222 on its front. The probe connecting shaft 222 has a spring 223 at its tail end, a wire hole 224 on its top, a positioning groove 225 on its side, and connects to the staggered segmented probe 226 at its front end. The probe 226 has a connection port 227 at its top, an LED light 228 at its upper part, a positioning camera 229 in its middle, and a needle tip 230 at its bottom.

[0024] In this embodiment, the hatch 101, when closed, is used to seal the vacuum chamber 1; when open, it is used to replace the measurement sample 10 or repair the test platform 2. The sliding shaft 103 connects the hatch 101 and the chamber 102. The base 104 supports the chamber 102, and its internal cylindrical gap supports the movement of the sliding shaft 103. The observation window 105 facilitates observation of the interior of the vacuum chamber 1. There is one or more handles 106 for opening and closing the hatch 101. There are two or more load-bearing wheels 107 for supporting the hatch 101, reducing resistance during opening and closing, and making the movement of the hatch 101 smoother. The carrying plate 108 is used to place the measurement platform 2 and can slide on the load-bearing wheels 110, following the movement of the hatch 101. After the vacuum chamber 1 is closed, the loading plate 108 covers the loading plate support rollers 110; the camera 109 is used to capture the test situation inside the vacuum chamber 1; the loading plate support rollers 110 are used to support the loading plate 108, prevent it from deforming, and keep the measuring platform 2 above it stable during the opening and closing of the chamber door 101; the exhaust connection hole 111 is used to connect to an external vacuum pump, allowing other gases inside the vacuum chamber 1 to be discharged through this hole; the signal and wiring connection hole 112 is used to collect all data lines and power lines inside the vacuum chamber 1, facilitating external connection; the measuring platform base 201 is used to mount the three-dimensional moving platform and the sample stage 204, and has several positioning holes 203 distributed on its surface, facilitating the three-dimensional moving platform or the sample stage 204 to move at different positions on the measuring platform base 201. The measuring platform 2 is fixed with bolts to accommodate the hole depth measurement of samples 10 of different sizes; the leveling knob 202 supports the measuring platform 2 and is leveled using a level; the positioning hole 203 positions the three-dimensional moving platform base 205 and the sample stage 204 to meet measurement requirements; the sample stage 204 is used to hold the measuring sample 10; the three-dimensional moving platform base 205 is used to set the X-axis, Y-axis, and Z-axis moving platforms; the sample clamp 206 is used to fix the measuring sample 10, and the measuring sample 10 and the probe are connected to the measuring circuit via the wire 207; the X-axis motor base 208, the X-axis motor drive plate 209, and the motor 215 cooperate to achieve precise movement in the X-axis direction; the Y-axis motor base 210, the Y-axis motor drive plate 211, and the motor 216 cooperate to jointly... Achieving precise movement in the Y-axis direction; rib plate 212 is used to connect and fix the Y-axis motor drive plate 211 and the Z-axis motor base 213; the Z-axis motor base 213, Z-axis motor drive plate 214 and motor 215 cooperate to achieve precise movement in the Z-axis direction; motor 215 is a piezoelectric ceramic motor to enable probe 226 to achieve precise micron-level movement; probe mounting base 216 is used to connect the Z-axis motor drive plate 214 and probe connecting shaft slot 217 to fix the two; probe connecting shaft slot 217 is used to accommodate and fix probe connecting shaft 222, transmitting the movement of the three-dimensional moving platform to probe 226, so that probe 226 moves according to the set trajectory; circuit integrator 218 integrates signal lines and power lines, shielding the influence of other signals;The electrical signal integration cable 219 is a cable integrating signal and power lines; when the locking button 220 is pressed, the probe connecting shaft 222 is completely fixed in the probe connecting shaft slot 217; when the eject button 221 is pressed, the probe connecting shaft 222 is released to allow replacement or repair of the probe 226; the probe connecting shaft 222 is used to mount the probe 226, enabling the probe 226 to move with high precision in the X, Y, and Z axes; the spring 223 cooperates with the positioning groove 225 to make the probe connecting shaft 222 more stable; the wire hole 224 is used to pass through the signal and power lines; the positioning groove 225 is a positioning groove for fixing the probe connecting shaft 222, which matches the protruding structure inside the probe connecting shaft slot 217, and under the action of the spring 223, the connection of the probe connecting shaft 222 is more secure; the probe 226 is a flexible probe with bending performance and impact resistance. The device features impact resistance to prevent damage from impact failures. Internally, it uses a low-resistance metal core wire, including corrosion-resistant precious metals such as platinum. The outer layer is coated with a highly elastic non-metallic material, including polyethylene, through coating or vapor deposition. Only the needle tip 230 is exposed, ensuring that during discharge, the microcurrent only passes through the needle tip 230 and the surface of the sample 10, preventing discharge of the probe 226 from affecting the detection results. The connection port 227 is used to connect and fix the probe connecting shaft 222 to the probe 226. An LED light 228 illuminates the sample 10, facilitating the location of the test hole. A positioning camera 229 locates the test hole position on the sample 10 and displays the surface morphology information of the sample 10 on a monitor. The needle tip 230 approaches the bottom of the inner wall of the test hole in the sample 10, cooperating with the measurement circuit to measure the hole depth.

[0025] This example involves a micropore depth measuring device.

[0026] The vacuum controller 3, the electrical signal loading feedback system 4, the three-dimensional moving platform controller 5, the video display 6, and the vacuum pump 7 are connected to the vacuum controller 3, the electrical signal loading feedback system 4, and the three-dimensional moving platform controller 5 respectively. The vacuum controller 3, the electrical signal loading feedback system 4, and the three-dimensional moving platform controller 5 are then connected to the central control system 8. The control software of the central control system 8 is programmed and different measurement modes are edited to meet various special test requirements, so as to obtain the hole depth and the 3D scanning morphology of the hole inner wall. The internal morphology of the hole is displayed non-destructively, which effectively solves the technical problem of 3D morphology observation of micro-holes.

[0027] Vacuum controller 3 receives instructions from central control system 8 and acts on vacuum pump 7 to control the vacuum level in vacuum chamber 1 and feeds back to central control system 8. Electrical signal loading feedback system 4 loads pulse voltage signals onto the measurement circuit and collects current signals in the measurement circuit. Three-dimensional moving platform controller 5 receives instructions from central control system 8 and moves probe 226 via motor 215. Video display 6 displays the image inside vacuum chamber 1 to confirm whether the measurement process is in a normal state. Vacuum pump 7 is connected to vacuum chamber 1 through exhaust connection hole 111. Central control system 8 controls and coordinates vacuum controller 3, electrical signal loading feedback system 4 and three-dimensional moving platform controller 5 to enable them to perform their respective functions, and analyzes the feedback data obtained.

[0028] Determine the size of the measurement sample 10, fix the sample stage 204 and the three-dimensional moving platform base 205 to the appropriate position of the measurement platform base 201, adjust the test platform 2 to be horizontal by adjusting the leveling knob 202, fix the measurement sample 10 on the sample stage 204 by the sample clamp 206, close the door 101, and evacuate the vacuum under the control of the central control system 8 to make the vacuum degree reach the set requirements.

[0029] The probe tip 230 is moved to the top of the sample 10 using a three-dimensional moving platform. A flat area outside the hole is selected for zero-point calibration. Three or five test points are selected around the hole, and the average value of the Z-axis is used as the zero reference point for the hole depth. The probe 226 is moved to the top of the hole. According to the set operating program, an initial pulse voltage is applied between the probe 226 and the sample 10, and the instantaneous current value is detected. When the distance between the probe 226 and the sample 10 is far, the measurement circuit is open and no instantaneous current is generated. When the probe 226 continues to descend until it is at a critical position from the inner wall of the hole, a tip discharge occurs, and the measurement circuit generates an instantaneous current. The current triggers the motor 215 on the Z-axis to run, causing the probe 226 to stop descending. The position of the Z-axis at this time is recorded. Then, a lower voltage pulse voltage is applied, and the probe 226 continues to descend along the Z-axis until the measurement circuit generates an instantaneous current again. This process is repeated until an instantaneous current can still be generated under the set pulse voltage. The Z value at this time is recorded, which is the hole depth. The measurement data is processed and analyzed to output the final hole depth.

[0030] After obtaining the hole depth, the vacuum in the vacuum chamber 1 is released under the control of the central control system 8, the door 101 is opened, the measuring sample 10 is taken out and replaced, the door 101 is closed, the vacuum is evacuated, and the next hole depth measurement is carried out.

[0031] Example 2:

[0032] This example involves a micropore depth measuring device to measure the micropore depth of 316L stainless steel after corrosion in ferric chloride solution. The pitting corrosion of 316L stainless steel in ferric chloride solution results in small but deep pits. The specific measurement process is as follows:

[0033] First, clean and dry the stainless steel;

[0034] Then, the stainless steel is fixed on the sample stage 204, leveled, and a probe 226 with a diameter of 50μm is selected.

[0035] Finally, close hatch 101 and evacuate the system to a vacuum level of 10. -4 mbar, move probe 226 to the vicinity of the hole to be measured, perform initial zero-point measurement calibration at three random positions around the hole to obtain the Z-axis value with a hole depth of 0, then move probe 226 to 1cm directly above the hole, select the "vortex" measurement mode, and make the needle tip 230 spiral down along the inner wall of the hole, select 3 microholes for measurement, and obtain hole depths of 673.4μm, 711.7μm and 310.2μm respectively.

Claims

1. A micropore depth measuring device, the main structure of which includes a vacuum chamber and a measuring platform disposed within it, characterized in that, The main structure of the vacuum chamber includes interconnected doors and chambers; the main structure of the measurement platform includes a measurement platform base and a three-dimensional moving platform and sample stage mounted on it, as well as probes mounted on the three-dimensional moving platform. The probe is a flexible probe with bending performance and impact resistance. The internal core wire is made of low-resistance metal wire, including the corrosion-resistant precious metal material platinum. The outer layer is coated with a non-metallic material with good elasticity, including polyethylene material, through coating or vapor deposition. Only the tip of the probe is exposed. During measurement, the device is connected to control software, which is configured to apply a set pulse voltage between the measurement sample and the probe, and detect the instantaneous micro-current between the measurement sample and the probe. The probe is controlled to make micro-movements in the X and Y axes during its descent to explore the edge of the micropore sidewall of the sample. The Z value is measured under different XY coordinates to obtain the value of the deepest part of the micropore. When the distance between the probe and the bottom of the micropore approaches the set value and a tip discharge occurs between the sample and the probe, an instantaneous microcurrent is detected. At the same time, the three-dimensional moving platform is controlled to stop moving and the depth in the Z-axis direction is recorded. The pulse voltage is reduced, and the probe is controlled to continue to descend in the Z-axis direction at a low speed until an instantaneous microcurrent is detected again. The three-dimensional moving platform stops moving, and so on, until the downward movement of the probe completely stops under a certain pulse voltage. At this time, the relative depth in the Z-axis direction is the pore depth of the sample.

2. The micropore depth measuring device according to claim 1, characterized in that, The main structure of the vacuum chamber includes a door and a chamber connected by two sliding shafts. One end of the sliding shaft is fixedly connected to the bottom of the door, and the other end extends into the base of the chamber and slides. The front of the door is equipped with an observation window and a handle, the bottom is equipped with load-bearing wheels, and the inner side is equipped with a loading plate. The top of the chamber is equipped with a camera, the bottom is equipped with several arrayed load-bearing wheels, and the back is equipped with an exhaust connection hole and signal and wiring connection holes.

3. The micropore depth measuring device according to claim 2, characterized in that, The main structure of the measurement platform includes a measurement platform base, leveling knobs, positioning holes, a sample stage, a three-dimensional moving platform base, sample clamps, wires, an X-axis motor base, an X-axis motor drive board, a Y-axis motor base, a Y-axis motor drive board, stiffening plates, a Z-axis motor base, a Z-axis motor drive board, a motor (a piezoelectric ceramic motor), a probe mounting base, a probe connecting shaft slot, a wiring integrator, an electrical signal integrator, a locking button, a pop-out button, a probe connecting shaft, a spring, wire holes, positioning slots, probes, a connector, LED lights, a positioning camera, and a needle tip. Leveling knobs are located at the four corners of the bottom of the measurement platform base, and several positioning holes are evenly spaced on the two sides of the top. The sample stage and the three-dimensional moving platform base are positioned on the measurement platform base through the corresponding positioning holes according to the set requirements. A sample clamp is provided on the sample stage to hold the measured sample. The sample holder has a wire at its tail end; the three-dimensional moving platform base has, from bottom to top, an X-axis motor base, an X-axis motor drive board, a Y-axis motor base, a Y-axis motor drive board, a rib, a Z-axis motor base, and a Z-axis motor drive board. Motors are installed on the X-axis, Y-axis, and Z-axis motor drive boards. The Z-axis motor drive board connects to the probe connecting shaft slot via a probe mounting base. The probe connecting shaft slot has a wiring integrator and electrical signal integrator on its top, a locking button on its side, a pop-out button on its bottom, and connects to the probe connecting shaft on its front. The probe connecting shaft has a spring at its tail end, a wire hole on its top, a positioning groove on its side, and connects to a staggered segmented probe at its front. The probe has a connection port at its top, an LED light at the top, a positioning camera in the middle, and a needle tip at its bottom.

4. The micropore depth measuring device according to claim 2, characterized in that, When the hatch is closed, it is used to seal the vacuum chamber; when it is open, it is used to replace the measurement sample or repair the test platform. The sliding shaft is used to connect the hatch and the chamber. The base is used to support the chamber, and the internal cylindrical gap supports the operation of the sliding shaft. The observation window facilitates observation of the internal conditions of the vacuum chamber. The chamber has one or more handles for opening and closing the door; two or more load-bearing wheels to support the door and reduce resistance during opening and closing; a loading plate to hold the measurement platform and slides on the loading plate's load-bearing wheels, following the door's movement; after the door is closed, the loading plate covers the loading plate's load-bearing wheels; a camera to capture the experimental conditions inside the vacuum chamber; loading plate load-bearing wheels to support the loading plate; an exhaust connection hole for connecting an external vacuum pump; and signal and wiring connection holes for connecting data and power lines inside the vacuum chamber.

5. The micropore depth measuring device according to claim 3, characterized in that, The measurement platform base is used to mount the three-dimensional moving platform and sample stage. Several positioning holes are distributed on the surface to facilitate bolt-fixing of the three-dimensional moving platform or sample stage at different positions on the measurement platform base. The leveling knob is used to support the measurement platform and level it using a level. The positioning holes are used to position the three-dimensional moving platform base and sample stage. The sample stage is used to hold the measurement sample; the 3D moving platform base is used to set the X-axis, Y-axis, and Z-axis moving platforms; the sample clamp is used to fix the measurement sample, and the measurement sample and probe are connected to the measurement circuit through wires; the X-axis motor base, X-axis motor drive board, and motor work together to achieve precise movement in the X-axis direction; the Y-axis motor base, Y-axis motor drive board, and motor work together to achieve precise movement in the Y-axis direction; the stiffener is used to connect and fix the Y-axis motor drive board and the Z-axis motor base; the Z-axis motor base, Z-axis motor drive board, and motor work together to achieve precise movement in the Z-axis direction; the motor is a piezoelectric ceramic motor; the probe mounting base is used to connect the Z-axis motor drive board and the probe connecting shaft slot; the probe connecting shaft slot is used to accommodate and fix the probe connecting shaft, transmitting the movement of the 3D moving platform to the probe, so that the probe moves according to the set trajectory; Line integrators integrate signal lines and power lines, shielding them from the influence of other signals; The electrical signal integrated cable is a cable that integrates signal lines and power lines; when the locking button is pressed, the probe connecting shaft is completely fixed in the probe connecting shaft slot; when the eject button is pressed, the probe connecting shaft is released; the probe connecting shaft is used to mount the probe; the spring cooperates with the positioning groove; the wire hole is used to pass through the signal line and the power line; The positioning groove is a positioning groove for fixing the probe connecting shaft. It matches the protruding structure inside the probe connecting shaft slot. Under the action of the spring, the connection of the probe connecting shaft is more secure. The connector is used to connect and secure the probe to the probe shaft; the LED light illuminates the sample being measured. The positioning camera is used to locate the test hole of the sample and displays the surface morphology information of the sample on the monitor; The needle tip approaches the bottom of the inner wall of the test hole in the sample and, in conjunction with the measurement circuit, performs hole depth measurement.

6. A micropore depth measuring device according to any one of claims 1-5, characterized in that, It is applicable to open holes with a large width-to-depth ratio and a large aperture. The positioning camera on the probe accurately determines the position of the bottom of the hole, and the probe moves in the Z-axis direction according to the selected position to obtain the accurate hole depth. When the width-to-depth ratio is small and the aperture is small, the positioning camera finds the location of the micro-hole, and the probe moves along the spiral trajectory, descending along the inner wall surface of the hole in a spiral manner to make measurements.

7. The micropore depth measuring device according to claim 6, characterized in that, The specific measurement process is as follows: The system is connected to a vacuum controller, an electrical signal loading feedback system, a 3D moving platform controller, a video display, and a vacuum pump. Then, the vacuum controller, electrical signal loading feedback system, and 3D moving platform controller are connected to the central control system. The control software of the central control system is programmed, and different measurement modes are edited to meet various testing requirements, obtaining the hole depth and 3D scan morphology of the hole's inner wall, with non-destructive display of the hole's internal morphology. The vacuum controller receives instructions from the central control system and acts on the vacuum pump, thereby controlling the vacuum level in the vacuum chamber and feeding back to the central control system. The electrical signal loading feedback system applies pulse voltage signals to the measurement circuit and collects the current signals in the measurement circuit. The 3D moving platform controller receives instructions from the central control system, drives the probe to move via a motor, and displays the image inside the vacuum chamber on a video monitor to confirm whether the measurement process is normal. The vacuum pump is connected to the vacuum chamber through the exhaust connection hole. The central control system controls and coordinates the vacuum controller, the electrical signal loading feedback system, and the 3D moving platform controller, receives feedback data, and analyzes it. It determines the size of the sample to be measured, fixes the sample stage and the 3D moving platform base in the appropriate position on the measurement platform base, adjusts the test platform to be level by adjusting the leveling knob, fixes the sample to be measured on the sample stage using the sample clamp, closes the chamber door, and, under the control of the central control system, evacuates the vacuum to achieve the set vacuum level. The probe tip is positioned above the sample using a three-dimensional moving platform. A flat area outside the hole is selected for zero-point calibration. Three or five test points around the hole are selected, and the average value of the Z-axis is used as the zero reference point for the hole depth. The probe is moved directly above the hole. According to the set operating program, an initial pulse voltage is applied between the probe and the sample, and the instantaneous current value is detected. When the distance between the probe and the sample is far, the measurement circuit is open, and no instantaneous current is generated. When the probe continues to descend until it is at a critical position near the inner wall of the hole, a tip discharge occurs, and the measurement circuit generates an instantaneous current. The current triggers the motor on the Z-axis to run, stopping the probe from descending. The position of the Z-axis at this time is recorded. Then, a lower voltage pulse voltage is applied, and the probe continues to descend along the Z-axis until an instantaneous current appears in the measurement circuit again. This process is repeated until an instantaneous current appears under the set pulse voltage. The Z value at this time is recorded, which is the hole depth. The measurement data is processed and analyzed to output the final hole depth. After obtaining the hole depth, the vacuum in the vacuum chamber is released under the control of the central control system, the door is opened, the measurement sample is taken out and replaced, the door is closed, the vacuum is evacuated, and the next hole depth measurement is carried out.

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