Embroidery product quality detection auxiliary equipment and detection method thereof

Abstract

The invention relates to the technical field of embroidery product manufacturing, and particularly discloses embroidery product quality detection auxiliary equipment which comprises a driving part, a protective shell and a conveying line, the protective shell comprises a second shell used for luminosity detection, a gear ring is installed on the second shell, a connecting edge is fixedly connected to the inner side wall of the gear ring, and the connecting edge is fixedly connected to the outer side wall of the gear ring. One end of the connecting ridge is fixedly connected with a projection plate, the projection plate is provided with a radiation lamp tube for projecting light beams in a radial shape, and the projection plate is further provided with a camera; an annularly-arranged optical filter is further installed in the second shell, and a space for the projection plate to move exists between the optical filter and the second shell. According to the invention, not only can the color contrast condition of patterns under visible light with different colors be measured, but also whether the area and thickness of the patterns meet sample standards can be detected, so that unqualified products can be quickly found out, the detection efficiency can be improved, and the qualified rate of detection is more stable.

Description

Technical Field

[0001] The invention relates to the technical field of embroidery product manufacturing, and in particular to an embroidery product quality detection auxiliary device and a detection method thereof. Background Art

[0002] With the development and progress of society, cultural development has attracted more and more attention, especially in the Jiangsu and Zhejiang areas, where embroidery has developed rapidly. There are many kinds of fabrics used for embroidery, and the most beautiful and popular one is transparent fabric, on which trademarks, leaves, logos and various small patterns are embroidered.

[0003] In order to ensure that the final products in the hands of consumers are qualified, most of them add a manual test at the end of the process. In the absence of light changes in the room, the color of the embroidery products is directly observed to see if they are qualified. This detection method lacks color contrast, resulting in unstable inspection pass rate of embroidery products. Summary of the invention

[0004] The purpose of the present invention is to solve the following shortcomings in the prior art: directly observing and detecting the color of embroidery products in the absence of light changes indoors, lacking color contrast, resulting in unstable detection pass rate of embroidery products, and proposing an embroidery product quality detection auxiliary equipment and a detection method thereof.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: An auxiliary device for embroidery product quality inspection, comprising a driving member, a protective shell and a transport line, wherein the protective shell comprises a second shell for photometric inspection, wherein a gear ring is mounted on the second shell, wherein a connecting rib is fixedly connected to the inner side wall of the gear ring, wherein one end of the connecting rib is fixedly connected to a projection board, wherein a radiation lamp tube with a radially arranged projection beam is arranged on the projection board, and a camera is also mounted on the projection board; The second housing is also provided with an annular filter, and there is a space between the filter and the second housing for the projection board to move, and the filter is divided into a plurality of regions with different colors; The transport line comprises a transport track, on which a clamp is slidably connected; A conductive strip 1 is installed on the inner wall of the shell 2, the projection plate is provided with a conductive column 1 electrically connected to the radiation lamp tube, a conductive spring 1 is provided at the bottom end of the conductive column 1, and the other end of the conductive spring 1 is electrically connected to the radiation lamp tube.

[0006] Preferably, a receiving plate is further provided at one end of the connecting ridge away from the projection plate, the receiving plate and the projection plate are symmetrical about the center line of the second housing, a photosensitive plate is provided on the receiving plate, and the photosensitive plate is electrically connected to the server terminal through a sensor; The projection board is also provided with a direct-emitting lamp tube, the direct-emitting lamp tube is connected to a conductive column 2 via a conductive spring 2, the conductive column 2 is electrically connected to a conductive strip 2, the number of the conductive strips 2 is two, and they are symmetrically mounted on the inner side wall of the housing 2, and the conductive column 2 and the conductive column 1 are staggered; The filter comprises two ring-shaped plates, and the plates and the first conductive strip have the same curvature and length.

[0007] Preferably, the clamp comprises a first clamp and a second clamp, the first clamp has a larger diameter than the second clamp and is lower in height than the second clamp, and both sides of the second clamp are provided with stabilizing claws slidably connected to the transport track.

[0008] Preferably, a telescopic rod is also installed in the shell, and the bottom end of the telescopic rod is fixedly connected to an assembly plate, a accommodating cavity is provided in the assembly plate, a plurality of needle columns are slidably connected to the bottom side of the assembly plate, the upper ends of the needle columns pass through the bottom side wall of the assembly plate and are connected to a baffle, a movable plate is also installed in the accommodating cavity, a resistance strain gauge is installed on the bottom side wall of the movable plate, and a display screen is connected to the resistance strain gauge through a wire.

[0009] Preferably, the movable plate is rotatably connected with a bolt, and the bolt passes through the upper side wall of the accommodating cavity and is threadedly connected thereto.

[0010] Preferably, the colors of different areas on the filter are arranged in a gradient manner.

[0011] Preferably, a buffer block with a flat bottom surface is installed at the bottom end of each needle column.

[0012] A method for detecting the quality area of ​​an embroidery product, confirming various parameter values ​​of a standard sample, the parameter values ​​at least including the length and width of the sample; Project the shadow of the standard sample on the photosensitive board, confirm that the resistance is the standard value and record it as R1; According to R1, set the upper and lower thresholds, namely R1+L and R1-L, where L is the maximum error value; Project the shadow of the sample to be tested on the photosensitive board to confirm the resistance value Rx; Determine whether Rx is within the range between R1+L and R1-L. If Rx is not within the range, it is an unqualified sample, and if it is within the range, it is a qualified sample.

[0013] A method for detecting the quality thickness of an embroidery product, confirming various parameter values ​​of a standard sample, the parameter values ​​at least including the length, width and height of the sample; According to the parameters of the standard sample, the shape and quantity of the needle columns are confirmed, a two-dimensional coordinate system is established, and the arrangement of the needle columns is marked in the two-dimensional coordinate system in the form of coordinate points, and the data of the standard sample is moved into the two-dimensional coordinate system; Mark the part of the standard sample that coincides with the coordinate point of the needle column in the two-dimensional coordinate system, retain the needle column in this part, and discard the rest; Set the preset sample resistance to the standard value and record it as R2. Set the upper and lower thresholds according to R2, i.e. R2+L and R2-L, where L is the maximum error value. Use the retained needle column to contact the sample to be tested to obtain the resistance value Ry, and judge whether Ry is within the range between R2+L and R2-L. If Ry is not within the range, it is an unqualified sample, and if it is within the range, it is a qualified sample. Compared with the prior art, the present invention has the following beneficial effects: It can not only measure the color contrast of patterns under different colors of visible light, but also detect whether the area and thickness of the pattern meet the sample standards, so as to quickly find unqualified products. It can not only improve the detection efficiency, but also make the detection pass rate more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a front structural schematic diagram of an embroidery product quality inspection auxiliary device proposed by the present invention; Figure 2 This is a schematic diagram of the axis two-viewing angle structure of an embroidery product quality inspection auxiliary device proposed by the present invention; Figure 3 It is a schematic diagram of the local cross-section result of the shell 2; Figure 4 It is a partial structural schematic diagram of the arrangement of the conductive strip 1 and the conductive strip 2 in the housing 2; Figure 5 It is a schematic diagram of the local cross-sectional structure of the assembly plate; Figure 6 It is a schematic diagram of the top view structure of the projection plate; Figure 7 It is a top view structural schematic diagram of the assembly plate; Figure 8 Schematic diagram of the top view of the clamp; Fig. 9 It is a schematic diagram of the shape structure illuminated by different lamps; Fig.10 It is a schematic diagram of the partial front structure of shell 2.

[0015] In the figure: 1 driving member, 2 protective shell, 3 filter, 4 shell one, 5 transport track, 6 receiving plate, 7 photosensitive plate, 8 conductive strip one, 9 shell two, 10 camera, 11 radiation lamp tube, 12 projection plate, 13 connecting rib, 14 gear ring, 15 direct lamp tube, 16 bolt, 17 assembly plate, 18 telescopic rod, 19 clamp, 20 baffle, 21 needle column, 22 resistance strain gauge, 23 clamp ring one, 24 clamp ring two, 25 movable plate, 26 conductive column one. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0017] Reference Figure 1-Figure 9 An auxiliary device for embroidery product quality inspection includes a driving member 1, a protective shell 2 and a transport line. The protective shell 2 includes a shell 9 for photometric detection. The photometric detection here refers to the visual effect of the embroidery product displayed under different colors of light. A gear ring 14 is installed on the shell 9. Figure 1 As shown, the driving member 1 includes a driving motor, the output end of the driving motor is connected to the rotating shaft, and the rotating shaft is provided with a gear meshing with the gear ring 14. When the driving motor rotates the gear, it will also drive the gear ring 14 to rotate. The driving member 1 here can be replaced by other driving devices, including manual rotation. The gear ring 14 and the shell 29 are rotationally connected, that is, the rotation of the gear ring 14 does not affect the state of the shell 29 remaining stationary. A connecting rib 13 is fixedly connected to the inner side wall of the gear ring 14, and the movement state between the two is consistent. One end of the connecting rib 13 is fixedly connected to a projection plate 12, and a radiation lamp tube 11 with a radially arranged projection light beam is provided on the projection plate 12. A camera 10 is also installed on the projection plate 12. The camera 10 is connected to the monitoring display end, and is mainly used to shoot the internal situation and then feed it back to the display end, so that the detection personnel can observe and monitor in time.

[0018] A ring-shaped filter 3 is also installed in the shell 2 9. There is a space between the filter 3 and the shell 2 9 for the projection plate 12 to move. The filter 3 is divided into a plurality of areas of different colors, so that visible light of different colors can be irradiated on the embroidery product to observe the color contrast of the product pattern and whether it is qualified.

[0019] The transport line includes a transport track 5, on which a clamp 19 is slidably connected. The middle part of the transport line is hollow, so that when the radiation lamp 11 is irradiated, only the front and back sides of the embroidery product will be irradiated to avoid light obstruction.

[0020] A conductive strip 8 is installed on the inner wall of the shell 29, and the projection plate 12 is provided with a conductive column 26 electrically connected to the radiation lamp tube 11. A conductive spring 1 is provided at the bottom end of the conductive column 26, and the other end of the conductive spring 1 is electrically connected to the radiation lamp tube 11. During the rotation of the projection plate 12, the conductive column 26 continuously contacts the conductive strip 1 under the action of the conductive spring 1, so that the circuit will be turned on, causing the radiation lamp tube 11 to emit light.

[0021] In the present invention, the driving member 1 drives the gear ring 14 to rotate, thereby driving the connecting rib 13 and the projection plate 12 on the connecting rib 13 to rotate, so that the projection plate 12 slides in the space between the filter 3 and the shell 2 9, and continuously rotates along the inner wall of the shell 2 9. There are filters 3 with different colors at different positions on the filter 3. In this way, when the projection plate 12 rotates, the light emitted by the radiation lamp tube 11 will hit the embroidery, and at this time the shape of the light beam is radial, such as Fig. 9 The shape below shows that there can be a larger illumination range, and the different colors of light displayed through the filter 3 are wider, and the detection effect is better. During the continuous rotation of the projection plate 12, the illumination color is constantly changing, and the visual effects of the embroidery under the illumination of different illumination colors are transmitted to the display end through the radiation lamp 11. Then the inspector can observe the color of the embroidery under different illumination through the display end, and can easily judge whether the embroidery is qualified, thereby ensuring the stability of the inspection efficiency.

[0022] like Fig.10 As shown, a receiving plate 6 is further provided at one end of the connecting rib 13 away from the projection plate 12, and the receiving plate 6 and the projection plate 12 are symmetrical about the center line of the shell 2 9. The light beam vertically shot from the projection plate 12 can be vertically irradiated on the receiving plate 6, and a photosensitive plate 7 is provided on the receiving plate 6. The photosensitive plate 7 is electrically connected to the server terminal through a sensor. The photosensitive plate 7 is a photoresistor. When the projection area and color depth on the photosensitive plate 7 are different, the resistance value of the photoresistor will change. The signal of the photosensitive plate 7 is transmitted to the server terminal through the sensor and displayed digitally. The brightness of the light is changed by using different light intensities. It has been widely used in life. Therefore, the connection relationship between the electrical components involved in the photoresistor, the sensor, and the server terminal belongs to the prior art, and its working principle is not described in detail.

[0023] A direct-light tube 15 is also provided on the projection board 12. The direct-light tube 15 is connected to a conductive column 2 through a conductive spring 2. The conductive column 2 is electrically connected to a conductive strip 2. There are two conductive strips 2, which are symmetrically mounted on the inner wall of the shell 2 9. The conductive column 2 and the conductive column 1 are staggered to avoid the radiation lamp 11 and the direct-light tube 15 from interfering with each other due to simultaneous irradiation. When the conductive column 2 and the conductive strip 2 are in contact, the direct-light tube 15 will emit light, but at this time, the conductive column 1 26 and the conductive strip 1 8 are not in contact, and the radiation lamp 11 will not emit light, and vice versa.

[0024] The filter 3 includes two ring-shaped plates. Figure 3 As shown, the curvature and length of the sheet and the conductive strip are the same. When the direct lamp tube 15 emits light, the light of the direct lamp tube 15 will not pass through the filter 3, but will directly illuminate the embroidery, and then be projected directly onto the photosensitive plate 7 without passing through the filter 3.

[0025] When the light beam of the direct lamp 15 directly projects the shadow of the embroidery on the photosensitive plate 7, since the fabric is transparent and the embroidery pattern is opaque, the shadow of the embroidery pattern is directly cast on the photosensitive plate 7, and the light intensity that the embroidery product allows the photosensitive plate 7 to receive will be determined, and a corresponding resistance value will be generated and displayed. This resistance value is compared with the sample resistance value. If it is within the error range, it is a qualified product. In this case, the factors affecting the light intensity of the photosensitive plate 7 are: there is a deviation in the length and width of the pattern embroidery, or there is a deviation in the embroidery density of the pattern, which leads to a change in the size of the shadow area on the photosensitive plate 7 or a change in the color depth of the shadow area. No matter what kind of change exceeds the error range, the embroidery is unqualified, thereby playing a detection role.

[0026] The clamp 19 includes a first clamp ring 23 and a second clamp ring 24. The diameter of the first clamp ring 23 is larger than that of the second clamp ring 24, and the height is lower than that of the second clamp ring 24. Both sides of the second clamp ring 24 are provided with stabilizing claws that are slidably connected to the transport track 5. Figure 8 As shown, the existing clamp 19 does not have a raised portion of the clamp ring 24. Figure 8 The clamp 19 shown covers the embroidery fabric on the upper end surface of the clamp ring 24 and tightens it, which helps the embroidery product to directly contact the light and reduce the light obstruction, and is helpful for detecting the embroidery thickness.

[0027] A telescopic rod 18 is also installed in the shell 14, and the telescopic rod 18 can control the assembly plate 17 to move downward. The bottom end of the telescopic rod 18 is fixedly connected to the assembly plate 17, and an accommodating cavity is provided in the assembly plate 17. A plurality of needle posts 21 are slidably connected to the bottom side of the assembly plate 17. The upper ends of the needle posts 21 penetrate the bottom side wall of the assembly plate 17 and are connected to a baffle 20. A movable plate 25 is also installed in the accommodating cavity. A resistance strain gauge 22 is installed on the bottom side wall of the movable plate 25. The resistance strain gauge 22 is connected to a display screen through a wire. When the assembly plate 17 moves downward, the needle posts 21 are driven to move downward and contact with the embroidery. The needle column 21 stops at a suitable height. At this time, see if the baffle 20 at one end of the needle column 21 is lifted up by the embroidery and contacts the resistance strain gauge 22. When contacting the resistance strain gauge 22, the resistance strain gauge 22 will be deformed under the action of pressure, thereby causing a change in resistance. The resistance resin is recorded. The resistance value is compared with the standard value. If it is within the error range, it is a qualified product, otherwise it is an unqualified product. The change of the resistance strain gauge 22 leads to a change in resistance. This technology is widely used in the field of electronic scales. The relationship between the designed electrical components belongs to the prior art, and the working principle is not described in detail.

[0028] The movable plate 25 is rotatably connected with a bolt 16, which passes through the upper side wall of the accommodating cavity and is threadedly connected thereto. The movable plate 25 can be rotated and slowly moved downward under the action of the threaded connection, so as to further adjust the distance between the resistance strain gauge 22 and the baffle 20 and increase the measurement accuracy.

[0029] The colors of different areas on the filter 3 are set in a gradient. The gradient design can make the same color have different shades, and there will be no obvious boundaries such as black or white. This can expand the range of color types on the filter 3, increase the range of color contrast, and further improve the stability and accuracy of detection.

[0030] A buffer block with a flat bottom surface is installed at the bottom end of each needle column 21. The buffer block is used to expand the contact area. The bottom end of the needle column 21 is inserted into the embroidery, which affects the detection result.

[0031] The invention discloses an embroidery product quality area detection method, which confirms various parameter values ​​of a standard sample, and the parameter values ​​at least include the length and width of the sample.

[0032] The shadow of the standard sample is projected onto the photosensitive plate 7. The photosensitive plate 7 confirms that the resistance value of the resistor is the standard value and records it as R1 according to the area and color depth of the projected shadow. The upper and lower thresholds are set according to R1, namely R1+L and R1-L, where L is the maximum error value.

[0033] The shadow of the sample to be tested is projected onto the photosensitive plate 7, and the shape of the light beam is as follows: Fig. 9 The upper part is shown in a rectangular setting. The shape of the light beam can be changed by changing the focal length, just like a flashlight in life. Confirm the resistance value Rx of the resistor and judge whether Rx is within the range between R1+L and R1-L. If Rx is not within the range, it is an unqualified sample, and if it is within the range, it is a qualified sample.

[0034] A method for detecting the quality thickness of an embroidery product, confirming various parameter values ​​of a standard sample, the parameter values ​​at least including the length, width and height of the sample; According to the parameters of the standard sample, the shape and quantity of the needle column 21 are confirmed, a two-dimensional coordinate system is established and the arrangement of the needle column 21 is marked in the two-dimensional coordinate system in the form of coordinate points, and the data of the standard sample is moved into the two-dimensional coordinate system to form an image of the sample in the coordinate system.

[0035] Mark the part that overlaps with the coordinate point of the standard sample and the needle column 21 in the two-dimensional coordinate system. Each coordinate point represents the position of the needle column 21, and the needle column 21 in this part is retained, and the rest is completely discarded, that is, taken out from the assembly plate 17, retaining the overlapping part, and then driving the telescopic rod 18 to drive the assembly plate 17 to move downward to a suitable height, which is recorded as H. The height of the assembly plate 17 for subsequent embroidery inspection is H. At this height, the bottom end of the needle column 21 contacts the pattern on the embroidery, which will lift the needle column 21 and contact the resistance strain gauge 22. At this time, the resistance strain gauge 22 will be deformed, thereby generating a resistance change. The final stable resistance is R2, which is the standard value.

[0036] The upper and lower thresholds are set according to R2, namely R2+L and R2-L, where L is the maximum error value.

[0037] The retained needle column 21 is in contact with the sample to be tested, and the height of the assembly plate 17 is also H. At this time, the resistance value Ry is obtained. The higher the thickness of the embroidery pattern, the higher the position of the needle column 21, the greater the pressure of the needle column 21 on the resistance strain gauge 22, and the greater the resistance. Conversely, the smaller the resistance, it is determined whether Ry is within the range between R2+L and R2-L. If Ry is not within the range, it is an unqualified sample, indicating that the thickness of the part of the embroidery pattern is thicker or thinner than the designed sample. If it is within the range, it is a qualified sample.

[0038] The above technical solution can not only measure the color contrast of patterns under different colors of visible light, but also detect whether the area and thickness of the pattern meet the sample standards, so as to quickly find unqualified products. It can not only improve the detection efficiency, but also make the detection pass rate more stable.

[0039] In addition, the above-mentioned equipment involves control settings such as timing and fixed points, and automatic control can be achieved using PLC. This belongs to the prior art and is not shown in the figure, so it will not be described in detail.

[0040] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An embroidery product quality inspection auxiliary device, comprising a driving member (1), a protective shell (2) and a transport line, characterized in that: The protective shell (2) comprises a second shell (9) for photometric detection, a gear ring (14) being mounted on the second shell (9), a connecting rib (13) being fixedly connected to the inner side wall of the gear ring (14), one end of the connecting rib (13) being fixedly connected to a projection plate (12), a radiation lamp tube (11) being arranged on the projection plate (12) with a projection light beam arranged radially, and a camera (10) being also mounted on the projection plate (12); A ring-shaped filter (3) is also installed in the second shell (9), and there is a space between the filter (3) and the second shell (9) for the projection plate (12) to move, and the filter (3) is divided into a plurality of areas with different colors; The transport line comprises a transport track (5), and a clamp (19) is slidably connected to the transport track (5); A conductive strip (8) is installed on the inner wall of the shell (9), and the projection plate (12) is provided with a conductive column (26) electrically connected to the radiation lamp (11). A conductive spring (1) is provided at the bottom end of the conductive column (26), and the other end of the conductive spring (1) is electrically connected to the radiation lamp (11).

2. The embroidery product quality detection auxiliary equipment according to claim 1, characterized in that: A receiving plate (6) is also provided at one end of the connecting rib (13) away from the projection plate (12), the receiving plate (6) and the projection plate (12) being symmetrical about the center line of the second shell (9), a photosensitive plate (7) is provided on the receiving plate (6), and the photosensitive plate (7) is electrically connected to a server terminal via a sensor; The projection plate (12) is also provided with a direct-emitting lamp tube (15), the direct-emitting lamp tube (15) being connected to a conductive column (2) via a conductive spring (2), the conductive column (2) being electrically connected to a conductive strip (2), the conductive strip (2) being two in number and symmetrically mounted on the inner side wall of the second housing (9), the conductive column (2) being staggered with the conductive column (1); The optical filter (3) comprises two sheets arranged in a ring shape, and the sheet and the conductive strip 1 have the same curvature and length.

3. The embroidery product quality detection auxiliary equipment according to claim 2, characterized in that: The clamp (19) comprises a first clamp ring (23) and a second clamp ring (24); the first clamp ring (23) has a larger diameter than the second clamp ring (24) and is lower in height than the second clamp ring (24); and both sides of the second clamp ring (24) are provided with stabilizing claws which are slidably connected to the transport track (5).

4. The embroidery product quality inspection auxiliary equipment according to claim 3, characterized in that: A telescopic rod (18) is also installed in the shell (4), and the bottom end of the telescopic rod (18) is fixedly connected to the assembly plate (17). The assembly plate (17) is provided with a receiving cavity. A plurality of needle posts (21) are slidably connected to the bottom side of the assembly plate (17). The upper ends of the needle posts (21) penetrate the bottom side wall of the assembly plate (17) and are connected to a baffle (20). A movable plate (25) is also installed in the receiving cavity. A resistance strain gauge (22) is installed on the bottom side wall of the movable plate (25), and the resistance strain gauge (22) is connected to a display screen via a wire.

5. The embroidery product quality inspection auxiliary equipment according to claim 4, characterized in that: A bolt (16) is rotatably connected to the movable plate (25), and the bolt (16) passes through the upper side wall of the accommodating cavity and is threadedly connected thereto.

6. The embroidery product quality inspection auxiliary equipment according to claim 5, characterized in that: The colors of different areas on the filter (3) are arranged in a gradient manner.

7. The embroidery product quality inspection auxiliary equipment according to claim 6, characterized in that: The bottom end of each needle column (21) is provided with a buffer block whose bottom end surface is arranged in a flat surface.

8. An area detection method for the embroidery product quality detection auxiliary equipment according to claim 7, characterized in that: Confirm the parameter values ​​of the standard sample, which at least include the length and width of the sample; Project the shadow of the standard sample onto the photosensitive plate (7) and confirm that the resistance is the standard value and record it as R1; According to R1, set the upper and lower thresholds, namely R1+L and R1-L, where L is the maximum error value; Project the shadow of the sample to be tested onto the photosensitive plate (7) to confirm the resistance value Rx of the resistor; Determine whether Rx is within the range between R1+L and R1-L. If Rx is not within the range, it is an unqualified sample, and if it is within the range, it is a qualified sample.

9. A thickness detection method of the embroidery product quality detection auxiliary equipment according to claim 8, characterized in that: Confirm the parameter values ​​of the standard sample, which at least include the length, width and height of the sample; According to the parameters of the standard sample, the shape and quantity of the needle column (21) are confirmed, a two-dimensional coordinate system is established, and the arrangement of the needle column (21) is marked in the two-dimensional coordinate system in the form of coordinate points, and the data of the standard sample is moved into the two-dimensional coordinate system; Mark the part of the standard sample that overlaps with the coordinate point of the needle column (21) in the two-dimensional coordinate system, retain the needle column (21) in this part, and remove all other parts; Set the preset sample resistance to the standard value and record it as R2. Set the upper and lower thresholds according to R2, i.e. R2+L and R2-L, where L is the maximum error value. The retained needle column (21) is used to contact the sample to be tested, and the resistance value Ry is obtained to determine whether Ry is within the range between R2+L and R2-L. If Ry is not within the range, the sample is unqualified, and if it is within the range, the sample is qualified.

Images