Label scanning type nonmetal container defect detection sensor, system and method

Abstract

The invention discloses a label scanning type nonmetal container defect detection sensor, system and method, and relates to the technical field of microwave nondestructive detection. The sensor comprises a medium substrate, an SSPPs transmission line and a high-dielectric-constant label sliding block arranged in an induction field area of the transmission line. The label sliding block is configured to generate relative displacement in the extending direction of the transmission line so as to conduct scanning. According to the invention, pre-bias regulation and control are carried out on local electric field distribution of the sensor through the high-dielectric-constant tag, so that a signal with cut-off frequency rising to high frequency caused by the low-dielectric-constant defect falls into a detectable range, and the problem that a traditional SSPPs sensor cannot detect a blind area of the low-dielectric-constant defect is solved. By recording the S parameter cut-off frequency offset and the direction thereof in the scanning process, qualitative identification and wide-area accurate positioning of superficial defects and deep liquid leakage of the nonmetal container are realized. The method has the advantages of high detection sensitivity, good spatial resolution and capability of distinguishing defect types.

Description

Technical Field

[0001] This invention relates to the field of microwave nondestructive testing technology, specifically to a label scanning sensor, system, and method for detecting defects in non-metallic containers. Background Technology

[0002] In industries such as chemical engineering, aerospace, and energy, non-metallic containers (such as composite material storage tanks, high-pressure gas cylinders, and Teflon delivery pipes) are widely used for storing and transporting strong acids, strong alkalis, volatile or toxic liquid media due to their advantages such as light weight, corrosion resistance, good insulation, and ease of molding. However, during manufacturing or long-term service, these containers are highly susceptible to structural defects such as microcracks, porosity, debonding, or impurity inclusions on the surface or inside the material due to process defects, environmental aging, or complex loads. If these micro-defects are not detected and addressed in time, they may evolve into penetrating cracks during use, leading to leakage of hazardous media and potentially causing serious environmental pollution or safety accidents. Therefore, conducting highly sensitive, wide-area structural health testing on non-metallic containers has significant engineering application value.

[0003] In recent years, Spoof Surface Plasmon Polaritons (SSPPs) technology, as a novel microwave sensing method, has attracted much attention in the field of sensing due to its strong subwavelength field confinement capability, high environmental sensitivity, and flexible structure. SSPP transmission lines exhibit significant low-pass filtering characteristics, and their cutoff frequency is extremely sensitive to changes in the dielectric constant of the surrounding medium. Although SSPP sensors have shown advantages in areas such as trace liquid detection, the following three key technical challenges remain unresolved when applying them to wide-area defect detection in non-metallic containers:

[0004] I. Detection Blind Zone Due to Low Dielectric Constant Defects. Traditional SSPPs sensors utilize the principle that an increase in the dielectric constant of the analyte causes a shift in the cutoff frequency to lower frequencies. However, in the inspection of non-metallic containers, common defects such as pores or cavities, filled with air, have a relative dielectric constant much lower than that of the container material. Low dielectric constant defects lead to a decrease in the local equivalent dielectric constant, theoretically causing the cutoff frequency to shift to higher frequencies. Due to the low-pass characteristics of SSPPs transmission lines, signals shifting to higher frequencies often exceed the passband or are masked by the fundamental mode cutoff frequency, resulting in a lack of effective response mechanisms for pore-like defects, making detection difficult.

[0005] Second, there is a lack of wide-area scanning and precise positioning capabilities. Current SSPPs sensors mostly use a fixed, attached method for single-point measurements, which can only reflect the average medium characteristics within the sensor's coverage area. For large or irregularly shaped non-metallic containers, achieving full-coverage inspection often requires a high-density sensor array, significantly increasing system cost and complexity. Furthermore, due to inconsistencies between individual units, it is difficult to achieve high-precision spatial positioning of defects. Existing technology lacks an effective solution for continuous scanning of a wide surface area using a single high-sensitivity probe.

[0006] Third, insufficient deep defect detection capability. The electromagnetic field of plasmons on artificial surfaces decays exponentially, mainly concentrating on the structural surface, with limited penetration depth. For deep cracks or non-penetrating damage inside non-metallic container walls, surface sensors often cannot directly capture the resulting dielectric constant perturbations. Although liquid leakage is a direct consequence of deep penetrating defects, current technology lacks an integrated, highly sensitive detection scheme that can simultaneously cover early porosity defects and late-stage liquid leakage.

[0007] Therefore, developing a new type of non-metallic container detection sensor and system that can break through the low dielectric detection blind zone, has wide-area scanning and positioning capabilities, and can effectively identify the risk of deep leakage is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0008] This invention provides a label-scanning sensor, system, and method for detecting defects in non-metallic containers, achieving high-sensitivity detection and precise location of low- and high-dielectric-constant defects over a wide range of non-metallic containers. This is achieved through the following technical solution:

[0009] A label-scanning non-metallic container defect detection sensor includes a dielectric substrate; an artificial surface plasmon transmission line (ASPL) disposed on the dielectric substrate; and a label slider. The ASPL includes a metal unit structure periodically arranged along the signal transmission direction to support the transmission of ASPL waves. The label slider is disposed within the sensing field region of the ASPL and configured to generate relative displacement along the extension direction of the ASPL, thereby changing the sensor's equivalent cutoff frequency by altering the label slider's position. The relative permittivity of the label slider is greater than that of the container material under test, thus forming an equivalent high-dielectric environment.

[0010] Based on the above scheme, the artificial surface plasmon transmission line further includes a coplanar waveguide section, a matching transition section, and a signal transmission section connected in sequence; the signal transmission section is composed of multiple rectangular toothed metal units of the same size arranged periodically, serving as the main sensing area; the tooth width of the metal units in the matching transition section gradually increases in a gradient direction away from the coplanar waveguide section, so as to realize the mode conversion and impedance matching of the microwave signal.

[0011] Building upon the aforementioned scheme, furthermore, to ensure measurement stability and sensor durability, a preset non-contact gap is maintained between the lower surface of the tag slider and the upper surface of the artificial surface plasmon transmission line. This non-contact gap is configured to allow strong coupling of electromagnetic field energy between the tag slider and the transmission line, while avoiding physical contact loss between them, thus ensuring the smoothness of the scanning process and the stability of the signal.

[0012] This invention also provides a label-scanning non-metallic container defect detection system, including the label-scanning non-metallic container defect detection sensor as described above; it also includes a driving component, a microwave signal transceiver module, a relative displacement mechanism, and a data processing unit. The driving component is connected to the label slider and configured to drive the label slider to move and scan along the extension direction of the plasmon transmission line on the artificial surface, achieving one-dimensional detection along the length of the sensor. The microwave signal transceiver module is electrically connected to the input and output ports of the sensor, used to send microwave excitation signals to the sensor and collect transmission scattering parameters. The relative displacement mechanism is used to support and fix the container under test, configured to drive relative displacement between the container under test and the sensor, to cooperate with the moving scan of the label slider to form a two-dimensional detection area, thereby covering a wider detection range. The data processing unit is communicatively connected to the microwave signal transceiver module, used to record scattering parameters at different scanning positions and determine the defect type based on the offset of the cutoff frequency.

[0013] Based on the above solution, the driving component further includes a sliding control unit and a slide rail mechanism; the sliding control unit is used to control the displacement of the label slider; the slide rail mechanism is a guide mechanism arranged along the extension path of the sensor; the label slider is suspended below the slide rail mechanism by a rigid connector and faces the transmission line of the sensor to ensure the relative positional accuracy between the label slider and the transmission line.

[0014] The present invention also provides a label scanning method for detecting defects in non-metallic containers, which is performed using the above-mentioned sensor and includes the following steps:

[0015] S1: Attach the label scanning non-metallic container defect detection sensor to the surface of the container to be tested;

[0016] S2: Control the relative displacement of the label slider along the sensing field region of the plasmon transmission line on the artificial surface, and obtain the S-parameter curve of the sensor at each scanning position through the microwave signal transceiver module;

[0017] S3: Extract the cutoff frequency from the S-parameter curve, compare the cutoff frequency with the reference cutoff frequency in the defect-free state, and calculate the cutoff frequency offset;

[0018] S4: Determine whether the container under test has defects and the type of defects based on the positive and negative directions and amplitude of the cutoff frequency offset.

[0019] Based on the above scheme, further, step S4 specifically includes: calculating the frequency shift between the real-time cutoff frequency and the reference operating frequency; if the frequency shift is positive, that is, the cutoff frequency moves to a higher frequency, it is determined that there is a low dielectric constant defect at the current position; if the frequency shift is negative, that is, the cutoff frequency moves to a lower frequency, it is determined that there is a high dielectric constant defect at the current position.

[0020] Based on the above scheme, further, the low dielectric constant defects include cracks, pores or debonding inside the test container (05); the high dielectric constant defects include non-metallic inclusions inside the test container (05); for deep defects in the test container (05) that cannot be detected, when they evolve into penetrating defects that cause liquid leakage, the liquid penetration area caused by the penetrating defects is detected as a high dielectric constant anomaly for indirect identification.

[0021] Based on the above scheme, a further step is to include a phased detection strategy: when the container under test is unloaded, a positive cutoff frequency offset is used to screen for shallow pores, and a negative cutoff frequency offset is used to screen for shallow impurities and defects; when the container under test is filled with liquid, in the area where shallow defects are excluded, a negative cutoff frequency offset is used to detect liquid penetration or leakage caused by deep cracks, thereby achieving indirect identification of deep hidden defects.

[0022] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0023] 1. This invention solves the detection blind zone problem of low dielectric constant defects. By introducing a high dielectric constant tag slider, the local electric field distribution of the sensor is pre-biased and controlled. In the defect-free state, the high dielectric tag already lowers the cutoff frequency; when encountering low dielectric constant defects such as pores and cracks, the local equivalent dielectric constant decreases, causing the cutoff frequency to rise to higher frequencies. This allows high-frequency shift signals that would otherwise be masked by low-pass characteristics to fall into the detectable range, thus achieving sensitive identification of air-type defects.

[0024] 2. This invention achieves qualitative differentiation and wide-area precise location of defect types. Through the mechanical scanning mechanism of the label slider, combined with the cooperation of the relative displacement mechanism, the invention can construct a two-dimensional detection area, which can not only detect defects but also accurately locate the coordinates of the defects on the container surface. Simultaneously, based on the positive and negative directions of the cutoff frequency shift (positive shift corresponds to porosity / debonding, negative shift corresponds to impurities / leakage), the system can directly qualitatively determine the physical properties of the defects.

[0025] 3. Capable of detecting deep defects and liquid leaks. Combining a phased detection strategy, this invention utilizes the principle that liquid penetration into deep cracks leads to a significant increase in the local dielectric constant, transforming deep structural damage that is difficult to detect directly into a high dielectric response (significant negative frequency shift) that is easy to detect, thereby effectively achieving health monitoring of non-metallic containers throughout their entire lifecycle. Attached Figure Description

[0026] To more intuitively illustrate exemplary embodiments of the present invention, the accompanying drawings required for the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and do not constitute a limitation on the entire scope. For those skilled in the art, other related drawings can still be derived from the drawings without inventive effort.

[0027] In the attached diagram:

[0028] Figure 1 This diagram shows the sensor structure.

[0029] Figure 2 A schematic diagram showing the sensor detection range in the high / low dielectric region when no tag is loaded;

[0030] Figure 3 A schematic diagram showing the detection range of the high / low dielectric region sensor after the tag is loaded;

[0031] Figure 4 A schematic diagram of the S-parameter curves of the sensor indicating whether or not a tagged object is present;

[0032] Figure 5 This is a schematic diagram of a defect detection system.

[0033] Figure 6 This diagram illustrates the detection of shallow defects in non-metallic materials.

[0034] Figure 7 This image shows the scan results of detecting shallow defects in non-metallic materials.

[0035] Figure 8 This is a simulation diagram illustrating a deep defect / liquid leak.

[0036] Figure 9A graph showing the change in cutoff frequency when the defect filling medium is oil;

[0037] Figure 10 This graph shows the change in cutoff frequency when the defect filling medium is isopropanol.

[0038] The markings and their corresponding component names in the attached diagram are as follows: 01-Sliding control unit, 02-Slide rail mechanism, 03-Label slider, 04-Microwave signal transceiver module, 05-Container under test, 06-Relative displacement mechanism, 07-Sensor, 08-Fixed bracket.

[0039] It is worth noting that similar labels and letters may represent the same or similar items in different figures. Therefore, if an item has been defined in one figure, it does not need to be defined and explained again in subsequent figures.

[0040] The objectives, features, and advantages of this invention will be described in more detail with reference to specific embodiments and the accompanying drawings. Detailed Implementation

[0041] To comprehensively, clearly, and accurately explain the purpose, core technical solution, and outstanding advantages of this invention, this article will rely on the appendix. Figures 1 to 10 This document describes in detail specific embodiments of the present invention. It is particularly emphasized that the embodiments mentioned below do not cover all possibilities of the invention, but are only provided as partial examples.

[0042] The embodiments disclosed in this invention provide a thorough explanation of the working principle, key structural features, and unique technical characteristics. However, given the broad scope of the microwave nondestructive testing technology field, those skilled in the art may propose other innovative embodiments, all of which fall within the protection scope of this invention.

[0043] Therefore, the content described herein is not intended to exhaustively cover all specific implementations of the invention, but rather to serve as a clear guide and source of inspiration for the technical community. Through the core concepts and implementation methods demonstrated in this invention, those skilled in the art can conceive of various other implementation methods without resorting to unconventional creative thinking; these methods are also protected by this invention.

[0044] Example 1

[0045] This embodiment provides a label scanning non-metallic container defect detection sensor 07, the core of which is to solve the problem of insufficient sensitivity of traditional artificial surface plasmon polariton (SSPP) sensors for detecting defects with low dielectric constants (such as bubbles and cavities).

[0046] like Figure 1As shown, the sensor 07 mainly consists of a dielectric substrate, a metal layer disposed on the upper surface of the substrate, and a high dielectric constant tag slider 03 suspended above the metal layer.

[0047] The dielectric substrate is made of a polyimide film with good flexibility, having a relative dielectric constant of 3.5, a loss tangent of 0.0027, and a thickness of 0.07 mm. The metal layer is made of copper with a thickness of 0.035 mm. This flexible material enables the sensor to closely adhere to the surface of the curved container.

[0048] The metal layer is etched into an artificial surface plasmon polariton transmission line, which is sequentially divided into three parts along the signal transmission direction: a coplanar waveguide section, a matching transition section, and a signal transmission section. The coplanar waveguide section is used to connect to an external microwave source to achieve impedance matching. The matching transition section is used to achieve an efficient conversion from the coplanar waveguide mode to the SSPPs mode; this section contains a series of gradient-graded metal units, and its tooth width or tooth depth gradually increases along the direction away from the coplanar waveguide section, which can effectively reduce the reflection loss caused by mode mismatch. The signal transmission section is the main sensing area, consisting of periodically arranged rectangular tooth-shaped metal units with the same size. In this embodiment, the unit period p = 4 mm, the tooth width w of the tooth-shaped rectangle = 3 mm, and the tooth depth h = 4 mm. This sub-wavelength structure can tightly confine the electromagnetic field on the surface of the structure to form a highly sensitive induction field.

[0049] As Figure 1 shown, the tag slider 03 is a block made of a high dielectric constant material. In this embodiment, a ceramic or composite material block with a relative dielectric constant of 20 is selected, and its size is 4 mm × 4 mm × 1 mm. The tag slider 03 is disposed above the signal transmission section, maintaining a preset non-contact gap of 0.05 mm from the surface of the transmission line. This gap can not only ensure strong coupling of the electromagnetic field but also avoid sliding friction loss.

[0050] As Figure 2 shown, the cut-off frequency of the traditional SSPPs sensor is f0. When encountering a defect with a dielectric constant lower than that of the container body (such as air, with a relative dielectric constant of 1), the local equivalent dielectric constant decreases, and the theoretical cut-off frequency should increase to f2. However, since f2 > f0 and SSPPs has a low-pass characteristic, this high-frequency signal is often masked by the cut-off characteristic of the passband, resulting in a detection blind area.

[0051] As Figure 3 shown, after introducing the high dielectric tag slider 03, the reference cut-off frequency of the sensor is pre-lowered to f1 (pre-bias). At this time, if a low dielectric constant defect is encountered, the cut-off frequency will rise from f1 to the high frequency to f3. Since f1 < f3 < f0, this rising signal is completely within the detectable range of the system, thus successfully eliminating the detection blind area and successfully opening up a low dielectric detection area.

[0052] Figure 4 The figure shows the simulated S-parameter curves of the sensor with and without a tagged object. The curve represented by the square (■) in the figure represents the reflectance S-parameter when no tag is loaded. 11 The triangle ▲ curve represents the reflectance S after the label is loaded. 12 The circular curve represents the transmission coefficient S when no tag is loaded. 21 The inverted triangle ▼ curve represents the transmission coefficient S after the tag is loaded. 22 .from Figure 4 It can be clearly seen that after loading the tag block, the transmission coefficient S 21 The cutoff frequency (usually taken at -10dB) shifted significantly to lower frequencies, verifying the effective control of the electromagnetic field by the high dielectric environment.

[0053] Example 2

[0054] This embodiment constructs a complete automated detection system, such as Figure 5 As shown, it is used to achieve wide-area scanning of the container under test 05; in this embodiment, the container under test 05 is a non-metallic pipe.

[0055] The system includes a sensor 07, a fixed bracket 08, a microwave signal transceiver module 04, a drive assembly, and a relative displacement mechanism 06.

[0056] The two ends of the sensor 07 are firmly supported by the fixed bracket 08, so that its flexible substrate can be closely attached to the outer surface of the container 05 to be tested.

[0057] In this embodiment, the microwave signal transceiver module 04 uses a vector network analyzer (VNA), which is connected to the input / output port of the sensor 07 via a coaxial cable to detect S in real time. 11 and S 21 parameter.

[0058] The drive assembly includes a slide rail mechanism 02 and a sliding control unit 01. The slide rail mechanism 02 is designed as an arched or conformal structure, spanning above the sensor, with its path parallel to the extension direction of the artificial surface plasmon transmission line. The label slider 03 is suspended below the slide rail mechanism 02 by a rigid connector and, driven by a precision motor in the sliding control unit 01, moves point by point along the transmission line in one unit cycle, realizing one-dimensional scanning along the length of the sensor.

[0059] In this embodiment, the relative displacement mechanism 06 employs an XYZ axis precision moving platform, on which the container 05 to be tested is placed. After the label slider 03 completes one scan along the X-axis, the relative displacement mechanism 06 drives the container 05 to move a certain distance along the Y-axis, and then the label slider 03 performs the next scan. Through the coordination of the X-axis slider movement and the Y-axis container movement, a two-dimensional wide-area detection area covering the container surface is formed.

[0060] Example 3

[0061] This embodiment details the specific method and test results for detecting defects in non-metallic containers using the above system, covering two stages: shallow defect screening and deep leak detection. The detection method flow is as follows:

[0062] S1: Attach sensor 07 to the surface of container 05 to be tested. In this embodiment, container 05 is made of Teflon with a relative permittivity of 2.1. Preheat vector network analyzer 04 and calibrate it.

[0063] S2: Control the label slider 03 to slide along the transmission line. Record the S-parameter curve of the current position for each step (4mm).

[0064] S3: Extract the cutoff frequency of the S-parameter curve and calculate the offset Δf between its real-time frequency and the defect-free reference frequency.

[0065] S4: Determine the defect type based on the sign and magnitude of Δf.

[0066] Figures 6-7 This demonstrates a scenario for the qualitative identification of shallow defects. For example... Figure 6 As shown, two different types of shallow defects (radius 2mm, height 2mm, distance from the surface 0.05mm) were placed directly below the 15th unit of the container under test 05. One type was an air defect (simulating pores), and the other was an impurity defect (simulating FR4 impurities with a relative permittivity of 4.2). Figure 7 As shown in the mid-peak value, when the slider moves above the air defect, the local equivalent dielectric constant decreases because the dielectric constant of air is lower than that of the Teflon body, causing the cutoff frequency to shift to higher frequencies. The system thus identifies this as a low-dielectric-constant defect (porosity / debonding). When encountering impurities with higher dielectric constants, the cutoff frequency shifts to lower frequencies. The system thus identifies this as a high-dielectric-constant defect. This result confirms that the present invention has the ability to qualitatively distinguish defect types.

[0067] Figures 8-10 This demonstrates scenarios for detecting deep defects and liquid leaks. For example... Figure 8 As shown, a penetrating microcrack with a depth of 0.05 mm was created, and liquid from the container was allowed to seep into it. Oil and isopropanol were used as the test liquids, with oil having a relative permittivity of 2.5 and isopropanol having a relative permittivity of 17.8. Figure 9 As shown, when the label slider scans to unit 15 (the leak), the cutoff frequency shows a negative shift (approximately -74.8MHz). This is because the seeping oil increases the local dielectric constant. Figure 10As shown, when the liquid was replaced with isopropanol with a high dielectric constant, the cutoff frequency showed an extremely significant negative shift (approximately -1787.5MHz), with a frequency shift amplitude much greater than that of the oil.

[0068] As shown in the table below (corresponding) Figure 9 and Figure 10 (Based on the data summary), the sensor responded to leaks of varying radii. Even with a leak radius of only 0.1 mm, the frequency shift caused by isopropanol reached -121.1 MHz, while the frequency shift caused by oil was -1 MHz. This indicates that the present invention can not only detect leaks caused by deep defects, but also roughly infer the nature of the leaking liquid or the scale of the leak based on the magnitude of the frequency shift.

[0069]

[0070] Liquids with different dielectric constants cause significant differences in frequency shift, which allows this invention not only to detect leaks but also to infer the type of leaking liquid from the magnitude of the frequency shift. Furthermore, this system exhibits extremely high sensitivity; even for tiny leak channels with a radius of only 0.1 mm, it can still detect observable frequency shift signals, verifying its advantages in detecting minute damage.

[0071] This embodiment verifies that the system utilizes a phased strategy to effectively transition from shallow porosity / impurity screening to deep leak detection, achieving comprehensive health diagnosis of non-metallic containers.

[0072] The specific embodiments described above have provided a detailed and in-depth explanation of the purpose, technical solution, and beneficial effects of this invention. The above content is merely some specific implementations of this invention and should not be used to limit the scope of protection of this invention. Through this detailed description, we aim to provide inspiration and guidance to those skilled in the art, encouraging them to innovate based on this invention to further enrich and expand the development of related technical fields. Such innovations may include various variations, improvements, or cross-disciplinary applications, and these variations and applications are also protected by this invention.

Claims

1. A label scanning type non-metallic container defect detection sensor (07), characterized in that, include: Dielectric substrate; Artificial surface plasmon transmission lines are disposed on the dielectric substrate and include metal unit structures arranged periodically along the signal transmission direction. The label slider (03) is disposed in the sensing field area of ​​the artificial surface plasmon transmission line and is configured to generate relative displacement along the extension direction of the artificial surface plasmon transmission line to change the equivalent cutoff frequency of the sensor (07); the relative permittivity of the label slider (03) is greater than the relative permittivity of the material of the container (05) under test.

2. The label scanning non-metallic container defect detection sensor (07) according to claim 1, characterized in that, The artificial surface plasmon transmission line includes: a coplanar waveguide section, a matching transition section, and a signal transmission section connected in sequence; the signal transmission section is composed of a periodically arranged plurality of rectangular toothed metal units of the same size; the tooth width of the metal units of the matching transition section increases gradually in a gradient away from the coplanar waveguide section.

3. The label scanning non-metallic container defect detection sensor (07) according to claim 1, characterized in that, The lower surface of the label slider (03) maintains a preset non-contact gap with the upper surface of the artificial surface plasmon transmission line.

4. The label scanning non-metallic container defect detection sensor (07) according to claim 3, characterized in that, The non-contact gap is configured to allow strong coupling of electromagnetic field energy between the label slider (03) and the transmission line, while avoiding physical contact loss.

5. A label scanning non-metallic container defect detection system, characterized in that, include: Label scanning non-metallic container defect detection sensor (07) as described in any one of claims 1 to 4; A driving component, connected to the label slider (03), is configured to drive the label slider (03) to move and scan along the extension direction of the artificial surface plasmon transmission line; The microwave signal transceiver module (04) is electrically connected to the input port and output port of the sensor (07) and is used to send microwave excitation signals to the sensor (07) and collect and transmit scattering parameters. The relative displacement mechanism (06) is used to support and fix the container under test (05), and is configured to drive the relative displacement between the container under test (05) and the sensor (07) to cooperate with the moving scan of the label slider (03) to form a two-dimensional detection area; The data processing unit is connected in communication with the microwave signal transceiver module (04) and is used to record the scattering parameters at different scanning positions and determine the defect type based on the offset of the cutoff frequency.

6. The label scanning non-metallic container defect detection system according to claim 5, characterized in that, The drive assembly includes a sliding control unit (01) and a slide rail mechanism (02); the sliding control unit (01) is used to control the displacement of the label slider (03); the slide rail mechanism (02) is a guide mechanism arranged along the extension path of the sensor (07); the label slider (03) is suspended below the slide rail mechanism (02) by a rigid connector and is directly opposite the transmission line of the sensor (07).

7. A label scanning method for detecting defects in non-metallic containers, characterized in that, Performed using the sensor (07) as described in any one of claims 1 to 4, the procedure includes the following steps: S1: Attach the label scanning non-metallic container defect detection sensor (07) to the surface of the container to be tested (05); S2: Control the label slider (03) to undergo relative displacement along the sensing field region of the plasmon transmission line on the artificial surface, and obtain the S-parameter curve of the sensor (07) at each scanning position through the microwave signal transceiver module (04); S3: Extract the cutoff frequency from the S-parameter curve, compare the cutoff frequency with the reference cutoff frequency in the defect-free state, and calculate the cutoff frequency offset; S4: Determine whether the container under test (05) has defects and the type of defects based on the positive and negative directions and amplitude of the cutoff frequency offset.

8. The label scanning method for detecting defects in non-metallic containers according to claim 7, characterized in that, Step S4 specifically includes: S41: Calculate the frequency shift between the real-time cutoff frequency and the reference operating frequency; S42: If the frequency shift is positive, it is determined that there is a low dielectric constant defect at the current location; S43: If the frequency shift is negative, it is determined that there is a high dielectric constant defect at the current position.

9. A label scanning method for detecting defects in non-metallic containers according to claim 8, characterized in that, The low dielectric constant defects include cracks, pores, or debonding inside the container under test (05); the high dielectric constant defects include non-metallic inclusions inside the container under test (05); for deep penetrating defects in the container under test (05), the liquid penetration area caused by the penetrating defects is indirectly identified as a high dielectric constant anomaly.

10. A label scanning method for detecting defects in non-metallic containers according to claim 8, characterized in that, It also includes a phased detection strategy: In the unloaded state of the container under test (05), the positive value of the cutoff frequency offset is used to screen for shallow pores, and the negative value of the cutoff frequency offset is used to screen for shallow impurity defects. When the container under test (05) is filled with liquid, liquid penetration or leakage caused by deep cracks is detected in the area excluding shallow defects by using a negative cutoff frequency offset.

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