Liquid detection apparatus and liquid detection method

Abstract

The application provides a liquid detection device and a liquid detection method. The liquid detection device comprises a capacitive plate and a processing circuit. The capacitive plate comprises a proximal plate, a distal plate and a ground plate which are arranged in the same plane and are spaced apart from each other. The proximal plate is arranged closer to the ground plate than the distal plate. The proximal plate and the ground plate form a proximal capacitor, and the distal plate and the ground plate form a distal capacitor. The processing circuit is electrically connected with the proximal capacitor and the distal capacitor. The processing circuit comprises a controller. The controller is used for obtaining a proximal capacitor detection value of the proximal capacitor and a distal capacitor detection value of the distal capacitor, and determining whether the liquid filled in the non-metallic tank body is a dangerous liquid according to the proximal capacitor detection value and the distal capacitor detection value. The embodiment of the application can reduce or avoid the influence of factors such as the concave degree and the thickness of the tank body, so that the detection result is more accurate, and the performance of the product is improved.

Description

Technical Field

[0001] This application relates to the field of liquid detection technology, and in particular to a liquid detection device and a liquid detection method. Background Technology

[0002] Parallel plate capacitance is a common method for determining whether a liquid filled in a non-metallic container is hazardous. However, in related technologies, the capacitance detection point of liquid detection equipment is singular and easily affected by factors such as the degree of indentation and thickness of the non-metallic container, leading to inaccurate detection results and seriously affecting product performance. Summary of the Invention

[0003] This application provides a liquid detection device and a liquid detection method that provide accurate detection results.

[0004] This application provides a liquid detection device for detecting whether a liquid filled in a non-metallic container is a hazardous liquid; the liquid detection device includes:

[0005] A capacitor plate includes a near-end plate, a far-end plate, and a ground plate arranged in the same plane and spaced apart from each other, wherein the near-end plate is positioned closer to the ground plate than the far-end plate; the near-end plate and the ground plate form a near-end capacitor, and the far-end plate and the ground plate form a far-end capacitor; and

[0006] The processing circuit is electrically connected to the near-end capacitor and the far-end capacitor. The processing circuit includes a controller, which is used to acquire the near-end capacitor detection value and the far-end capacitor detection value, and determine whether the liquid filled in the non-metallic tank is a hazardous liquid based on the near-end capacitor detection value and the far-end capacitor detection value.

[0007] Optionally, the controller is used to determine the difference between the near-end capacitance detection value and the near-end parasitic capacitance value of the near-end capacitor to obtain the near-end capacitance relative value of the near-end capacitor, and to determine the difference between the far-end capacitance detection value and the far-end parasitic capacitance value of the far-end capacitor to obtain the far-end capacitance relative value of the far-end capacitor; based on the near-end capacitance relative value and the far-end capacitance relative value, it is determined whether the liquid filled in the non-metallic tank is a hazardous liquid.

[0008] Optionally, the controller is used to determine whether the liquid filled in the non-metallic tank is a hazardous liquid based on the ratio of the relative value of the near-end capacitance to the relative value of the far-end capacitance.

[0009] Optionally, the controller is configured to determine that the liquid filled in the non-metallic container is a non-hazardous liquid if the ratio does not reach the danger threshold; or, if the ratio reaches the danger threshold, determine that the liquid filled in the non-metallic container is a hazardous liquid.

[0010] Optionally, the controller is further configured to acquire the capacitance value of the near-end capacitor as the near-end parasitic capacitance value when there is no test object, and to acquire the capacitance value of the far-end capacitor as the far-end parasitic capacitance value.

[0011] Optionally, the processing circuit further includes a conversion circuit, which includes a first conversion circuit and a second conversion circuit. The first conversion circuit is electrically connected to the proximal capacitor and the controller, and the second conversion circuit is electrically connected to the distal capacitor and the controller. The first conversion circuit is used to acquire the proximal vibration frequency of the proximal capacitor when the non-metallic container is filled with liquid, and the controller is used to determine the proximal capacitor detection value based on the proximal vibration frequency. The second conversion circuit is used to acquire the distal vibration frequency of the distal capacitor when the non-metallic container is filled with liquid, and the controller is used to determine the distal capacitor detection value based on the distal vibration frequency.

[0012] Optionally, the conversion circuit includes a NOT gate element and an oscillation circuit. The input terminal of the NOT gate element is electrically connected to the near-end capacitor or the far-end capacitor. The input terminal of the oscillation circuit is electrically connected to the output terminal of the NOT gate element. The controller is electrically connected to the output terminal of the oscillation circuit.

[0013] Optionally, the proximal electrode, the distal electrode, and the ground electrode each include finger-shaped capacitor plates, wherein the finger-shaped capacitor plate includes a main body and a plurality of spaced fingers connected to the main body.

[0014] Optionally, the proximal electrode includes a proximal electrode body, a plurality of first proximal fingers disposed on one side of the proximal electrode body, and a plurality of second proximal fingers disposed on the other side of the proximal electrode body. The first proximal fingers extend from the proximal electrode body toward the ground electrode, and the second proximal fingers extend from the proximal electrode body toward the distal electrode.

[0015] The grounding electrode plate includes a grounding electrode plate body and a plurality of first grounding fingers disposed on one side of the grounding electrode plate body. The first grounding fingers extend from the grounding electrode plate body toward the first proximal fingers and are arranged to intersect with the first proximal fingers.

[0016] The distal electrode plate includes a distal electrode plate body and a plurality of first distal fingers disposed on one side of the distal electrode plate body. The first distal fingers extend from the distal electrode plate body toward the side of the second proximal fingers and are arranged to intersect with the second proximal fingers.

[0017] Optionally, the grounding electrode plate further includes a plurality of second grounding fingers disposed on the other side of the grounding electrode plate body, the second grounding fingers extending from the grounding electrode plate body toward the side opposite to the first proximal finger.

[0018] Optionally, the distal electrode plate further includes a plurality of second distal fingers disposed on the other side of the distal electrode plate body, the second distal fingers extending from the distal electrode plate body toward the side opposite to the second proximal fingers.

[0019] Optionally, the proximal electrode plate has a rectangular structure or a spiral structure.

[0020] Optionally, the grounding plate may be a rectangular or spiral structure.

[0021] Optionally, the distal electrode plate has a rectangular structure or a spiral structure.

[0022] Optionally, the liquid detection device is a handheld liquid detection device.

[0023] This application also provides a liquid detection method applied to a liquid detection device, the liquid detection device including a capacitor plate, the capacitor plate including a proximal electrode plate, a distal electrode plate, and a ground electrode plate located in the same plane and spaced apart from each other, the proximal electrode plate being positioned closer to the ground electrode plate than the distal electrode plate; the proximal electrode plate and the ground electrode plate forming a proximal capacitor, and the distal electrode plate and the ground electrode plate forming a distal capacitor; the liquid detection method includes:

[0024] Obtain the near-end capacitance detection value of the near-end capacitor and the far-end capacitance detection value of the far-end capacitor; and

[0025] Based on the near-end capacitance detection value and the far-end capacitance detection value, it is determined whether the liquid filled in the non-metallic tank is a hazardous liquid.

[0026] Optionally, determining whether the liquid filled in the non-metallic container is a hazardous liquid based on the near-end capacitance detection value and the far-end capacitance detection value includes:

[0027] The difference between the near-end capacitance detection value and the near-end parasitic capacitance value of the near-end capacitor is determined to obtain the near-end capacitance relative value of the near-end capacitor.

[0028] The difference between the detected value of the far-end capacitance of the far-end capacitor and the value of the far-end parasitic capacitance of the far-end capacitor is determined to obtain the relative value of the far-end capacitance of the far-end capacitor.

[0029] Based on the relative values ​​of the near-end capacitance and the far-end capacitance, it is determined whether the liquid filled in the non-metallic container is a hazardous liquid.

[0030] Optionally, determining whether the liquid filled in the non-metallic container is a hazardous liquid based on the relative values ​​of the near-end capacitance and the far-end capacitance includes:

[0031] The ratio of the relative value of the near-end capacitance to the relative value of the far-end capacitance is used to determine whether the liquid filled in the non-metallic container is a hazardous liquid.

[0032] Optionally, determining whether the liquid filled in the non-metallic container is a hazardous liquid based on the ratio of the relative value of the near-end capacitance to the relative value of the far-end capacitance includes:

[0033] If the ratio does not reach the danger threshold, the liquid filled in the non-metallic container is determined to be a non-hazardous liquid; or

[0034] If the ratio reaches the danger threshold, the liquid filled in the non-metallic container is determined to be a dangerous liquid.

[0035] Optionally, the method provided in this application embodiment further includes:

[0036] When there is no test object, the capacitance value of the near-end capacitance is obtained and used as the near-end parasitic capacitance value.

[0037] When there is no object to be tested, the capacitance value of the far end capacitor is obtained and used as the far end parasitic capacitance value.

[0038] The step of obtaining the near-end capacitance detection value of the near-end capacitor and the far-end capacitance detection value of the far-end capacitor includes:

[0039] Obtain the proximal oscillation frequency of the proximal capacitor when the non-metallic container is filled with liquid;

[0040] The proximal capacitance detection value is determined based on the proximal vibration frequency;

[0041] Obtain the distal vibration frequency of the distal capacitor when the non-metallic container is filled with liquid;

[0042] The distal capacitance detection value is determined based on the distal vibration frequency.

[0043] The liquid detection device provided in this application includes a capacitor plate and a processing circuit. The near-end plate and the ground plate of the capacitor plate form a near-end capacitor, and the far-end plate and the ground plate form a far-end capacitor. The processing circuit is used to acquire the near-end capacitance detection value of the near-end capacitor and the far-end capacitance detection value of the far-end capacitor, and to determine whether the liquid filled in the non-metallic container is a hazardous liquid based on the near-end capacitance detection value and the far-end capacitance detection value. With this configuration, the liquid detection device uses the near-end capacitance detection value and the far-end capacitance detection value to determine the hazard of the liquid filled in the non-metallic container. The far-end plate and the near-end plate correspond to different positions on the non-metallic container, that is, different capacitance detection points are set at different positions. Detecting different positions on the non-metallic container separately can reduce or avoid the influence of factors such as the degree of dents and thickness of the container, making the detection results more accurate and improving the performance of the product.

[0044] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0045] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0046] Figure 1 The diagram shown is a schematic representation of one embodiment of the liquid detection device of this application.

[0047] Figure 2 As shown Figure 1 The circuit diagram of the liquid detection device shown is shown.

[0048] Figure 3 As shown Figure 1 The circuit diagram of the processing circuit of the liquid detection device shown is shown.

[0049] Figure 4 As shown Figure 1 A schematic diagram of one embodiment of the capacitor plate of the liquid detection device shown.

[0050] Figure 5 As shown Figure 1 A schematic diagram of another embodiment of the capacitor plate of the liquid detection device shown.

[0051] Figure 6 As shown Figure 1 A schematic diagram of yet another embodiment of the capacitor plate of the liquid detection device shown.

[0052] Figure 7 As shown Figure 1 A schematic diagram of another embodiment of the capacitor plate of the liquid detection device shown.

[0053] Figure 8 The diagram shown is a flowchart of one embodiment of the liquid detection method of this application.

[0054] Figure 9 The diagram shown is a flowchart of another embodiment of the liquid detection method of this application.

[0055] Figure 10 The diagram shown is a flowchart of another embodiment of the liquid detection method of this application.

[0056] Figure 11 The diagram shown is a flowchart of another embodiment of the liquid detection method of this application.

[0057] Figure 12 The diagram shown is a flowchart of another embodiment of the liquid detection method of this application. Detailed Implementation

[0058] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0059] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit the application. Unless otherwise defined, the technical or scientific terms used in this application should be understood in their ordinary sense by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms "a" or "one," etc., do not indicate a quantity limitation, but rather indicate the presence of at least one. "A plurality" or "several" indicates two or more. Unless otherwise indicated, the terms "front," "rear," "lower," and / or "upper," etc., are for ease of description only and are not limited to a location or spatial orientation. The terms "comprising" or "including," etc., mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. The terms "connected," "linked," etc., are not limited to physical or mechanical connections and can include electrical connections, whether direct or indirect.

[0060] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0061] This application provides a liquid detection device for detecting whether a liquid filled in a non-metallic container is a hazardous liquid. The liquid detection device includes a capacitor plate and a processing circuit. The capacitor plate includes a near-end plate, a far-end plate, and a ground plate located in the same plane and spaced apart from each other. The near-end plate is positioned closer to the ground plate than the far-end plate. The near-end plate and the ground plate form a near-end capacitor, and the far-end plate and the ground plate form a far-end capacitor. The processing circuit is electrically connected to the near-end capacitor and the far-end capacitor. The processing circuit includes a controller for acquiring the near-end capacitor detection value and the far-end capacitor detection value, and determining whether the liquid filled in the non-metallic container is a hazardous liquid based on the near-end capacitor detection value and the far-end capacitor detection value.

[0062] This liquid detection equipment uses near-end capacitance detection values ​​and far-end capacitance detection values ​​to determine the hazard of liquids filled in non-metallic containers. The far-end plate and the near-end plate correspond to different positions on the non-metallic container, that is, setting capacitance detection points at different positions and detecting different positions on the non-metallic container separately can reduce or avoid the influence of factors such as the degree of dents and thickness of the container, making the detection results more accurate and improving the performance of the product.

[0063] This application provides a liquid detection device and a liquid detection method. The liquid detection device and method of this application will be described in detail below with reference to the accompanying drawings. Unless otherwise specified, the features in the following embodiments and implementations can be combined with each other.

[0064] Figure 1 The diagram shown is a schematic diagram of one embodiment of the liquid detection device 20 of this application. Figure 2 As shown Figure 1 The circuit diagram of the liquid detection device 20 shown is shown. Figure 3 As shown Figure 1 The circuit diagram of the processing circuit 202 of the liquid detection device 20 shown. Figure 4 As shown Figure 1 A schematic diagram of one embodiment of the capacitor plate 201 of the liquid detection device 20 shown. (In conjunction with...) Figures 1 to 4As shown, the liquid detection device 20 is a hazardous liquid detection device used to detect whether the liquid filled in the non-metallic container 10 is a hazardous liquid. The hazardous liquid can be flammable, explosive, strong acid, strong alkali, or other similar liquids. In some embodiments, the liquid detection device 20 is a handheld liquid detection device that can be used for security inspections.

[0065] exist Figure 1 In the illustrated embodiment, the liquid detection device 20 is placed close to the non-metallic container 10 to detect the liquid filled inside the non-metallic container 10. The height of the non-metallic container 10 is equal to or greater than the maximum dimension of the liquid detection device 20. To ensure the accuracy of the detection results, the liquid filled inside the non-metallic container 10 needs to completely cover the detection surface of the liquid detection device 20. The non-metallic container 10 can be placed vertically (e.g., ...). Figure 1 The non-metallic container 10 can be placed vertically for testing, or it can be placed horizontally. Specifically, when the height of the liquid filling the non-metallic container 10 is equal to or greater than the maximum size of the liquid testing device 20, the non-metallic container 10 can be placed vertically for testing. When the height of the liquid filling the non-metallic container 10 is less than the maximum size of the liquid testing device 20, the non-metallic container 10 can be placed horizontally for testing. This ensures that the liquid filling the non-metallic container 10 completely covers the liquid testing device 20, resulting in more accurate test results.

[0066] The volume and shape of the non-metallic container 10 are not limited. For example, it can be a cylindrical structure or a cubic structure, and is not limited in this application. In this embodiment, for example, the size range of the liquid detection device 20 is 15mm*55mm to 20mm*60mm. The detection surface size of the liquid detection device 20 is also within the range of 15mm*55mm to 20mm*60mm. In some embodiments, the non-metallic container 10 can be a cylindrical structure with a diameter of at least 30mm, which can fully cover the detection surface of the liquid detection device 20. In other embodiments, the non-metallic container 10 can be a cubic structure, where the surface area of ​​one side of the cubic structure is at least larger than the detection surface mentioned above, so as to fully cover the detection surface of the liquid detection device 20. In other embodiments, the non-metallic container 10 can also be other irregular container structures. It has a wide range of applications.

[0067] exist Figures 2 to 4In the illustrated embodiment, the liquid detection device 20 includes a capacitor plate 201 and a processing circuit 202. The capacitor plate 201 includes a proximal electrode 203, a distal electrode 204, and a ground electrode 205, all located in the same plane and spaced apart from each other. The proximal electrode 203 is positioned closer to the ground electrode 205 than the distal electrode 204. The proximal electrode 203 and the ground electrode 205 form a proximal capacitor 207. The distal electrode 204 and the ground electrode 205 form a distal capacitor 208. The processing circuit 202 is electrically connected to the proximal capacitor 207 and the distal capacitor 208. The processing circuit 202 includes a controller 209, which acquires the proximal capacitance detection value of the proximal capacitor 207 and the distal capacitance detection value of the distal capacitor 208, and determines whether the liquid filled in the non-metallic container 10 is a hazardous liquid based on the proximal capacitance detection values ​​and the distal capacitance detection values. The near-end capacitance and far-end capacitance values ​​refer to the current measured values ​​of the near-end capacitance and far-end capacitance when the non-metallic container contains liquid, respectively.

[0068] In this embodiment, the capacitor plate 201 includes a flat substrate layer 206. A proximal electrode 203, a distal electrode 204, and a ground electrode 205 are disposed within the substrate layer 206 and are separately arranged. The extending directions of the proximal electrode 203, the distal electrode 204, and the ground electrode 205 are consistent with the extending plane of the substrate layer 206. The proximal electrode 203 and the distal electrode 204 are defined relative to the ground electrode 205, wherein the proximal electrode 203 is positioned closer to the ground electrode 205 than the distal electrode 204. The distance between the ground electrode 205 and the proximal electrode 203 and the distal electrode 204 is different, resulting in a different proximal capacitor 207 formed by the proximal electrode 203 and the ground electrode 205 compared to the distal capacitor 208 formed by the distal electrode 204 and the ground electrode 205.

[0069] Considering the different degrees of indentation in the non-metallic can 10, the different thicknesses of the cans, and the effects of different liquids on the dielectric constant, the dielectric constant of the liquid to be measured can be determined using a composite dielectric constant D. k If this is expressed, then the composite dielectric constant can be expressed as the dielectric constant of the tank (ε). bottle ), air (ε) air ), liquid (ε) liquid ), sheet material (ε) FR4 The capacitance of the plate-shaped capacitor 201 is C = εA / 4πkd. Where ε is the dielectric constant of the medium between the two plates, A is the area of ​​the plates, d is the distance between the two plates, and π and k are both constants. In this embodiment, the near-end plate 203 and the ground plate 205 form a near-end capacitor 207, and the capacitance detection value of the near-end capacitor 207 is expressed by formula (1). The far-end plate 204 and the ground plate 205 form a far-end capacitor 208, and the capacitance detection value of the far-end capacitor 208 is expressed by formula (2). Where Cap NearCap is used to represent the near-end capacitance detection value of near-end capacitor 207. Far The far-end capacitance detection value used to represent the far-end capacitance 208, Dk Near Dk represents the composite dielectric constant of the liquid under test corresponding to the near-end capacitance 207. Far This represents the composite dielectric constant of the liquid under test corresponding to the far-end capacitor 208. Formulas (1) and (2) are derived from the capacitance formula of the plate-shaped capacitor plate 201. Specifically:

[0070]

[0071]

[0072] Composite dielectric constant D k (i.e., Dk) Near or Dk Far ) and tank (ε bottle ), air (ε) air ), liquid (ε) liquid ), sheet material (ε) FR4 There is a relationship. The plate material is the same as that of capacitor plate 201, for example, FR-4. For the near-end capacitor 207, A represents the area of ​​the plates when the near-end plate and the ground plate form a capacitor, and d represents the distance between the plates when the near-end plate and the ground plate form a capacitor. For the far-end capacitor 208, A represents the area of ​​the plates when the far-end plate and the ground plate form a capacitor, and 2d represents the distance between the plates when the far-end plate and the ground plate form a capacitor. C0 is a constant in the capacitance calculation formula, C0 = 1 / 4πk.

[0073] For the same non-metallic container 10, its air (ε) air ), tank (ε) bottle ), and boards (ε FR4 The composite dielectric constant D is constant. k Mainly with liquids (ε) liquid Therefore, the dielectric constant of a liquid can be evaluated using capacitance detection values, and further, the hazard level of the liquid can be determined using the dielectric constant of the liquid. The processing circuit 202 acquires different near-end and far-end capacitance detection values. Using these values, the dielectric constant of the liquid filled in the non-metallic container 10 is determined. Based on the dielectric constant, the hazard level of the liquid is determined. The far-end plate 204 and the near-end plate 203 correspond to different positions on the non-metallic container 10, i.e., different capacitance detection points are set at different positions. Detection at different positions on the non-metallic container 10 reduces or avoids the influence of factors such as the degree of dent or thickness of the container, making the detection results more accurate and improving product performance.

[0074] In some embodiments, the controller 209 is used to determine the difference between the near-end capacitance detection value and the near-end parasitic capacitance value of the near-end capacitor 207, thereby obtaining the near-end capacitance relative value of the near-end capacitor 207. The near-end parasitic capacitance value is the inherent capacitance value between the near-end plate 203 and the ground plate 205 of the near-end capacitor 207 when there is no test object (e.g., no non-metallic can 10). This near-end parasitic capacitance value represents the capacitance value of the near-end capacitor 207 itself, unaffected by other dielectric constants, and is related to the dimensions between the near-end plate 203 and the ground plate 205 of the near-end capacitor 207. The near-end capacitance detection value is the capacitance value of the near-end capacitor 207 when the non-metallic can 10 is filled with liquid. The near-end capacitance detection value represents the sum of the inherent capacitance value of the near-end capacitor 207 and the liquid capacitance value, affected by the dielectric constant of the liquid, when the non-metallic can 10 is filled with liquid. The liquid capacitance value of the near-end capacitor 207 represents the change in capacitance value of the near-end capacitor 207 when the liquid to be tested is present.

[0075] In some embodiments, the controller 209 is used to determine the difference between the remote capacitance detection value and the remote parasitic capacitance value of the remote capacitor 208 to obtain the relative value of the remote capacitance of the remote capacitor 208. The remote parasitic capacitance value is the inherent capacitance value between the remote plate 204 and the ground plate 205 of the remote capacitor 208 when there is no test object (e.g., no non-metallic can 10). This remote parasitic capacitance value represents the capacitance value originating from the remote capacitor 208 itself, unaffected by other dielectric constants, and is related to the dimensions between the remote plate 204 and the ground plate 205 of the remote capacitor 208. The remote capacitance detection value is the capacitance value of the remote capacitor 208 when the non-metallic can 10 is filled with liquid. This remote capacitance detection value represents the sum of the inherent capacitance value of the remote capacitor 208 and the liquid capacitance value, affected by the dielectric constant of the liquid, when the non-metallic can 10 is filled with liquid. The liquid capacitance value of the remote capacitor 208 represents the change in capacitance value of the remote capacitor 208 when the liquid to be tested is present.

[0076] Furthermore, the controller 209 is used to determine whether the liquid filled in the non-metallic tank 10 is a hazardous liquid based on the relative values ​​of the near-end capacitance and the far-end capacitance. This configuration obtains the relative value of the near-end capacitance by the difference between the detected near-end capacitance value and the near-end parasitic capacitance value, and obtains the relative value of the far-end capacitance by the difference between the detected far-end capacitance value and the far-end parasitic capacitance value. This reduces the influence of the capacitance values ​​of the near-end and far-end capacitors themselves on the hazardous liquid determination, making the detection results more accurate.

[0077] For example, based on the above analysis, in the embodiments of this application, the dielectric constant of the liquid to be tested is related to the relative values ​​of the near-end capacitance and the far-end capacitance. For example, the dielectric constant of the liquid to be tested can be expressed as a function of the relative values ​​of the near-end capacitance and the far-end capacitance. The dielectric constant of the liquid to be tested is used to determine whether the liquid to be tested is a dangerous liquid, that is, the relative values ​​of the near-end capacitance and the far-end capacitance can be used to determine whether the liquid to be tested is a dangerous liquid.

[0078] In some embodiments, the controller 209 is used to determine whether the liquid filled in the non-metallic container 10 is a hazardous liquid based on the ratio of the relative value of the near-end capacitance to the relative value of the far-end capacitance. It should be understood that the ratio is a functional representation of the relative values ​​of the near-end and far-end capacitances in terms of the dielectric constant of the liquid being tested, and should not be construed as a specific limitation on the embodiments of this application. For example, other nonlinear or linear functional representations based on the relative values ​​of the near-end and far-end capacitances can be determined according to actual calculation needs, provided they can represent the dielectric constant of the liquid being tested.

[0079] In this embodiment, Cap Near Subtract Cap Near寄生 ΔCap is obtained Near ;Cap Far Subtract Cap Far寄生 ΔCap is obtained Far Among them, Cap Near寄生 The near-end parasitic capacitance value, ΔCap, is used to represent the near-end capacitance 207. Near Used to represent the relative value of the near-end capacitance 207. Far寄生 ΔCap is used to represent the far-end parasitic capacitance value of far-end capacitor 208. Far Used to represent the relative value of the far-end capacitance of the far-end capacitor 208.

[0080] Combining formulas (1) and (2) above, ΔCap Near ΔCap Far Dividing them yields formula (3);

[0081]

[0082] During the testing process, for the same non-metallic container 10, its air (ε) air ), tank (ε) bottle ), and boards (ε FR4 Given a given condition, the composite dielectric constant of the liquid being tested is primarily related to the liquid's dielectric constant (ε). liquid Related to ΔCap. Near ΔCap FarThe value obtained by division is positively correlated with the ratio between the near-end capacitance detection value of near-end capacitor 207 and the near-end capacitance detection value of far-end capacitor 208, that is, it obtains the value related to the liquid dielectric constant (ε). liquid The relevant functions serve as the basis for determining whether the liquid being tested is hazardous or non-hazardous. This setup simplifies the detection method and increases accuracy, reducing or eliminating the influence of factors such as the degree of dents or thickness of the tank, thus preventing false alarms and missed detections and improving product performance.

[0083] In some embodiments, the controller 209 determines the ratio of the relative value of the near-end capacitance to the relative value of the far-end capacitance. If the ratio does not reach a danger threshold, the liquid filled in the non-metallic container 10 is determined to be a non-hazardous liquid. If the ratio reaches a danger threshold, the liquid filled in the non-metallic container 10 is determined to be a hazardous liquid. For example, a danger threshold of 1.6 is set. When a ratio greater than 1.6 is detected, the liquid filled in the non-metallic container 10 is determined to be a hazardous liquid. When a ratio less than 1.6 is detected, the liquid filled in the non-metallic container 10 is determined to be a non-hazardous liquid. Different liquids have different danger thresholds. This danger threshold can be obtained through extensive data measurement and stored in the controller 209. It can be retrieved at any time when the controller 209 needs to make a judgment or determination. This not only limits the detection of a single liquid but also allows for the detection of the hazard of different liquids, broadening its application range and increasing its scalability.

[0084] exist Figure 2 In the illustrated embodiment, the processing circuit 202 further includes a conversion circuit, comprising a first conversion circuit 210 and a second conversion circuit 211. The first conversion circuit 210 is electrically connected to the near-end capacitor 207 and the controller 209. The second conversion circuit 211 is electrically connected to the far-end capacitor 208 and the controller 209. Figure 2 and Figure 3 In the illustrated embodiment, the first conversion circuit 210 is used to acquire the proximal vibration frequency of the proximal capacitor 207 when the non-metallic container 10 is filled with liquid. The controller 209 is used to determine the proximal capacitance detection value of the proximal capacitor 207 based on the proximal vibration frequency. Figure 3 In the illustrated embodiment, the processing circuit 202 further includes an electrical connector 212 for electrically connecting the capacitor plate 201, specifically to the near-end capacitor 207 and the far-end capacitor 208. The controller 209 is electrically connected to the output of the first conversion circuit 210. The first conversion circuit 210 is a NOT gate oscillation circuit, which may be a capacitor-to-frequency conversion circuit.

[0085] In some embodiments, the conversion circuit includes a NOT gate and an oscillating circuit. The input terminal of the NOT gate is electrically connected to the near-end capacitor 207 or the far-end capacitor 208, the input terminal of the oscillating circuit is electrically connected to the output terminal of the NOT gate, and the controller 209 is electrically connected to the output terminal of the oscillating circuit. The oscillating circuit may be an LC oscillating circuit.

[0086] exist Figure 3 In the illustrated embodiment, the first conversion circuit 210 includes a first NOT gate element 213 and a first oscillation circuit 214. The input terminal of the first NOT gate element 213 is electrically connected to the near-end capacitor 207, and the input terminal of the first oscillation circuit 214 is electrically connected to the output terminal of the first NOT gate element 213. The controller 209 is electrically connected to the output terminal of the first oscillation circuit 214. The first oscillation circuit 214 can be an LC oscillation circuit. The first oscillation circuit 214 includes a capacitor C1 and an inductor L1. The capacitor C1 is electrically connected between the output terminal of the first NOT gate element 213 and the ground terminal, and the inductor L1 is electrically connected between the output terminal and the input terminal of the first NOT gate element 213. The LC oscillation circuit, used in conjunction with the first NOT gate element 213, allows the input of the first conversion circuit 210 to oscillate back and forth between the "0" and "1" states, and its output terminal forms a rectangular wave with an oscillation frequency. The LC oscillation circuit is used to obtain the near-end vibration frequency of the near-end capacitor 207 when the non-metallic container 10 is filled with liquid. The controller 209 processes the near-end vibration frequency and derives the near-end capacitance detection value of the near-end capacitor 207 when the non-metallic tank 10 is filled with liquid. For example, the controller 209 can derive the near-end capacitance detection value C according to the formula f = 1 / [2π√(LC)], where the frequency is f, the capacitance is C, and the inductance is L. This configuration results in a simple, stable, and reliable circuit structure.

[0087] exist Figure 2 and Figure 3 In the illustrated embodiment, the second conversion circuit 211 is used to acquire the distal vibration frequency of the distal capacitor 208 when the non-metallic container 10 is filled with liquid, and the controller 209 is used to determine the distal capacitance detection value of the distal capacitor 208 based on the distal vibration frequency. Figure 4In the illustrated embodiment, the second conversion circuit 211 is a NOT gate oscillator circuit. The NOT gate oscillator circuit can be a capacitor-to-frequency conversion circuit. In this embodiment, the second conversion circuit 211 includes a second NOT gate element 223 and a second oscillator circuit 224. The input terminal of the second NOT gate element 223 is electrically connected to the remote capacitor 208, and the input terminal of the second oscillator circuit 224 is electrically connected to the output terminal of the second NOT gate element 223. The controller 209 is electrically connected to the output terminal of the second oscillator circuit 224. The second oscillator circuit 224 can be an LC oscillator circuit. The second oscillator circuit 224 includes a capacitor C2 and an inductor L2. The capacitor C2 is electrically connected between the output terminal of the second NOT gate element 223 and the ground terminal, and the inductor L2 is electrically connected between the output terminal and the input terminal of the second NOT gate element 223. The second conversion circuit 211 is similar to the first conversion circuit 210, and its specific implementation process and principle are similar, so they will not be described again here.

[0088] In some embodiments, the controller 209 is further configured to acquire the capacitance value of the near-end capacitor 207 as a near-end parasitic capacitance value when no test object is present. The detection method for this near-end parasitic capacitance value is the same as the method for detecting near-end capacitance values. The main difference is that the near-end parasitic capacitance value is the inherent capacitance value of the near-end capacitor 207 detected when no test object is present (e.g., no non-metallic can 10). In some embodiments, the controller 209 is further configured to acquire the capacitance value of the far-end capacitor 208 as a far-end parasitic capacitance value when no test object is present. The detection method for this far-end parasitic capacitance value is the same as the method for detecting far-end capacitance values. The main difference is that the far-end parasitic capacitance value is the inherent capacitance value of the far-end capacitor 208 detected when no test object is present (e.g., no non-metallic can 10).

[0089] After the test procedure begins, the near-end capacitor 207 and the far-end capacitor 208 are calibrated first to obtain the near-end parasitic capacitance value of the near-end capacitor 207 and the far-end parasitic capacitance value of the far-end capacitor 208. This near-end parasitic capacitance value represents the capacitance value originating from the near-end capacitor 207 itself, unaffected by other dielectric constants. Similarly, the far-end parasitic capacitance value represents the capacitance value originating from the far-end capacitor 208 itself, unaffected by other dielectric constants. These near-end and far-end parasitic capacitance values ​​are obtained in advance without the test object and can be stored in the controller 209 for retrieval when calibration is required.

[0090] The near-end and far-end vibration frequencies are then detected separately when the non-metallic can 10 is filled with liquid. The first conversion circuit 210 and the second conversion circuit 211 are used for reverse derivation to obtain the near-end and far-end capacitance detection values ​​when the non-metallic can 10 is filled with liquid. Then, the difference between the near-end parasitic capacitance value and the near-end capacitance detection value is used to obtain the near-end relative capacitance value. Similarly, the difference between the far-end parasitic capacitance value and the far-end capacitance detection value is used to obtain the far-end relative capacitance value. The near-end relative capacitance value is divided by the far-end relative capacitance value, and compared with a danger threshold. The safety of the liquid is determined based on the comparison result. The far-end plate 204 and the near-end plate 203 correspond to different positions on the non-metallic can 10, i.e., different capacitance detection points are set at different positions. Detecting different positions on the non-metallic can reduces or avoids the influence of factors such as the degree of dent or thickness of the can, making the detection results more accurate and improving product performance.

[0091] In some embodiments, the proximal electrode 203, the distal electrode 204, and the ground electrode 205 may have the same or different structures. In some embodiments, the proximal electrode 203, the distal electrode 204, and the ground electrode 205 may have regular or irregular shapes. This is not limited in this application. In some embodiments, the proximal electrode 203, the distal electrode 204, and the ground electrode 205 each include finger-shaped capacitor plates, each finger-shaped capacitor plate including a main body and a plurality of spaced-apart fingers connected to the main body. The fingers of the proximal electrode 203 and the ground electrode 205 are interleaved. The fingers of the proximal electrode 203 and the distal electrode 204 are interleaved.

[0092] exist Figure 4 In the illustrated embodiment, the proximal electrode 203, distal electrode 204, and ground electrode 205 have the same structure. The proximal electrode 203 includes a proximal electrode body 215, a plurality of first proximal fingers 216 disposed on one side of the proximal electrode body 215, and a plurality of second proximal fingers 217 disposed on the other side of the proximal electrode body 215. The first proximal fingers 216 extend from the proximal electrode body 215 toward the ground electrode 205, and the second proximal fingers 217 extend from the proximal electrode body 215 toward the distal electrode 204. The extending directions of the first proximal fingers 216 and the second proximal fingers 217 are the same (e.g., ...). Figure 4 (In the horizontal direction). The extension direction of the proximal electrode body 215 is perpendicular to the extension directions of the first proximal finger 216 and the second proximal finger 217 (e.g., in the horizontal direction). Figure 4(Vertical direction). The first proximal finger 216 and the second proximal finger 217 are distributed on both sides of the proximal electrode body 215 and are staggered in the extending direction of the proximal electrode body 215. In this embodiment, the first proximal finger 216 and the second proximal finger 217 are perpendicular to the extending direction of the proximal electrode body 215. The proximal electrode body 215 has a strip-shaped structure, and the first proximal finger 216 and the second proximal finger 217 are distributed in a finger-like shape on both sides of the proximal electrode body 215.

[0093] The grounding electrode 205 includes a grounding electrode body 218 and a plurality of first grounding fingers 219 disposed on one side of the grounding electrode body 218. The first grounding fingers 219 extend from the grounding electrode body 218 toward a first proximal finger 216 and are intersected by the first proximal finger 216. The extending direction of the first grounding fingers 219 is consistent with the extending direction of the first proximal finger 216 (e.g., ...). Figure 4 (Horizontal direction). In this embodiment, the first grounding finger 219 is perpendicular to the extending direction of the grounding electrode body 218. The grounding electrode body 218 has a strip-shaped structure, and the first grounding finger 219 is distributed in a finger-like shape on one side of the grounding electrode body 218. The extending direction of the grounding electrode body 218 is consistent with the extending direction of the proximal electrode body 215, and perpendicular to the extending direction of the first grounding finger 219 (e.g., horizontal direction). Figure 4 (Vertical direction). This configuration, compared to related technologies, increases the contact area between the near-end plate 203 and the ground plate 205, resulting in a larger capacitance value detected by the near-end capacitor and more accurate detection. Specifically, a larger capacitance detection value more accurately characterizes the dielectric constant of the liquid being tested, meaning more sensitive detection of the liquid. Simultaneously, a larger capacitance detection value reduces the impact of parasitic capacitance on the liquid detection results, and minimizes the influence of other capacitance errors caused by the capacitor structure on the liquid detection results, thus leading to more accurate liquid detection results.

[0094] The distal electrode 204 includes a distal electrode body 221 and a plurality of first distal fingers 222 disposed on one side of the distal electrode body 221. The first distal fingers 222 extend from the distal electrode body 221 toward the second proximal fingers 217 and are intersected with the second proximal fingers 217. The extending direction of the first distal fingers 222 is consistent with the extending direction of the second proximal fingers 217 (e.g., ...). Figure 4 (Horizontal direction). In this embodiment, the first distal finger 222 is perpendicular to the extension direction of the distal electrode body 221. The distal electrode body 221 has a strip-shaped structure, and the first distal finger 222 is distributed in a finger-like shape on one side of the distal electrode body 221. The extension direction of the distal electrode body 221 is consistent with the extension direction of the proximal electrode body 215, and perpendicular to the extension direction of the second proximal finger 217 (e.g., horizontal direction). Figure 4(Vertical direction). This configuration, compared to related technologies, increases the contact area between the near-end plate 203 and the far-end plate 204, which is equivalent to increasing the contact area between the far-end plate 204 and the ground plate 205. This results in a larger capacitance value detected by the far-end capacitor, leading to more accurate detection. Specifically, a larger capacitance value more accurately characterizes the dielectric constant of the liquid being tested, meaning more sensitive detection. Simultaneously, a larger capacitance value reduces the impact of parasitic capacitance on the liquid detection results, and minimizes the influence of other capacitance errors caused by the capacitor structure on the liquid detection results, thus resulting in more accurate liquid detection.

[0095] This configuration, with the first proximal finger 216 and the first ground finger 219 arranged in an alternating manner, and the second proximal finger 217 and the first distal finger 222 arranged in an alternating manner, increases the contact area between the proximal electrode 203 and the ground electrode 205, as well as between the proximal electrode 203 and the distal electrode 204, resulting in a larger capacitance value that is beneficial for detection and makes the detection results more accurate.

[0096] Figure 5 As shown Figure 1 A schematic diagram of another embodiment of the capacitor plate 301 of the liquid detection device shown. (See diagram below.) Figure 5 As shown, with Figure 4 Compared to the illustrated embodiment, the grounding electrode 205 further includes a plurality of second grounding fingers 320 disposed on the other side of the grounding electrode body 218. The second grounding fingers 320 extend from the proximal electrode body 315 toward the side opposite to the first proximal finger 316. The second grounding fingers 320 and the first grounding fingers 319 are distributed on both sides of the grounding electrode body 318 and are staggered in the extending direction of the grounding electrode body 318. The distal electrode 304 further includes a plurality of second distal fingers 323 disposed on the other side of the distal electrode body 321. The second distal fingers 323 extend from the distal electrode body 321 toward the side opposite to the second proximal finger 317. The second distal fingers 323 and the first distal fingers 322 are distributed on both sides of the distal electrode body 321 and are staggered in the extending direction of the distal electrode body 321.

[0097] This configuration increases the detection surface area of ​​the grounding plate 305 and the far-end plate 304, which can improve the sensitivity to liquids in non-metallic containers, enhance anti-interference capabilities, and make the detection results more accurate. Figure 4 and Figure 5 In comparison, by reducing the number of the second grounding finger 320 and the second far-end finger 323, the overall size of the capacitor board 301 is reduced, making the liquid detection device smaller and more portable.

[0098] In some embodiments, the proximal electrode is a rectangular or helical structure. In some embodiments, the distal electrode is a rectangular or helical structure. In some embodiments, the grounding electrode is a rectangular or helical structure.

[0099] Figure 6 As shown Figure 1 A schematic diagram of yet another embodiment of the capacitor plate 401 of the liquid detection device shown. Figure 6 In the illustrated embodiment, the near-end electrode 403, the far-end electrode 404, and the ground electrode 405 have the same structure, which is a rectangular structure. (Similar to...) Figure 5 Compared to the embodiments shown, its structure is a regular structure, the manufacturing process is simple, and the cost is low. Figure 7 As shown Figure 1 A schematic diagram of another embodiment of the capacitor plate 501 of the liquid detection device shown. Figure 7 In the embodiment shown, the near-end electrode 503, the far-end electrode 504, and the ground electrode 505 have the same structure, which is a spiral structure. The near-end electrode 503, the far-end electrode 504, and the ground electrode 505 are set separately for easy assembly.

[0100] Figure 8 The diagram shown is a flowchart of one embodiment of the liquid detection method of this application. Figure 8 As shown, the liquid detection method is applied to the liquid detection device 20. The liquid detection device 20 can be as described above. Figures 1 to 7 The liquid detection device 20 shown in the embodiment. For example... Figure 8 As shown, the liquid detection method includes steps S1-S2. Among them,

[0101] Step S1: Obtain the near-end capacitance detection value of the near-end capacitor 207 and the far-end capacitance detection value of the far-end capacitor 208. Combined with... Figure 8 and Figure 2 As shown, in this step, the controller 209 of the processing circuit 202 can be used to obtain the near-end capacitance detection value of the near-end capacitor 207 and the far-end capacitance detection value of the far-end capacitor 208. The near-end capacitor 207 and the far-end capacitor 208 can be obtained using... Figures 4 to 7 The near-end capacitor 207 and the far-end capacitor 208 are shown.

[0102] Step S2: Based on the near-end capacitance detection value and the far-end capacitance detection value, determine whether the liquid filled in the non-metallic container is a hazardous liquid. Combined with... Figure 8 and Figure 2 As shown, in this step, the controller 209 of the processing circuit 202 can determine whether the liquid filled in the non-metallic container is a dangerous liquid based on the near-end capacitance detection value and the far-end capacitance detection value.

[0103] Considering the different degrees of indentation in the non-metallic can 10, the different thicknesses of the cans, and the effects of different liquids on the dielectric constant, the dielectric constant of the liquid to be measured can be determined using a composite dielectric constant D. k If this is expressed, then the composite dielectric constant can be expressed as the dielectric constant of the tank (ε). bottle ), air (ε) air ), liquid (ε) liquid ), sheet material (ε) FR4 The capacitance of the plate-shaped capacitor 201 is C = εA / 4πkd. Where ε is the dielectric constant of the medium between the two plates, A is the area of ​​the plates, d is the distance between the two plates, and π and k are both constants. In this embodiment, the near-end plate 203 and the ground plate 205 form a near-end capacitor 207, and the capacitance detection value of the near-end capacitor 207 is expressed by formula (1). The far-end plate 204 and the ground plate 205 form a far-end capacitor 208, and the capacitance detection value of the far-end capacitor 208 is expressed by formula (2). Where Cap Near Cap is used to represent the near-end capacitance detection value of near-end capacitor 207. Far The far-end capacitance detection value used to represent the far-end capacitance 208, Dk Near Dk represents the composite dielectric constant of the liquid under test corresponding to the near-end capacitance 207. Far This represents the composite dielectric constant of the liquid under test corresponding to the far-end capacitor 208. Formulas (1) and (2) are derived from the capacitance formula of the plate-shaped capacitor plate 201. Specifically:

[0104]

[0105]

[0106] Composite dielectric constant D k (i.e., Dk) Near or Dk Far ) and tank (ε bottle ), air (ε) air ), liquid (ε) liquid ), sheet material (ε) FR4 There is a relationship. The plate material is the same as that of capacitor plate 201, for example, FR-4. For the near-end capacitor 207, A represents the area of ​​the plates when the near-end plate and the ground plate form a capacitor, and d represents the distance between the plates when the near-end plate and the ground plate form a capacitor. For the far-end capacitor 208, A represents the area of ​​the plates when the far-end plate and the ground plate form a capacitor, and 2d represents the distance between the plates when the far-end plate and the ground plate form a capacitor. C0 is a constant in the capacitance calculation formula, C0 = 1 / 4πk.

[0107] For the same non-metallic container 10, its air (ε) air), tank (ε) bottle ), and boards (ε FR4 The composite dielectric constant D is constant. k Mainly with liquids (ε) liquid Therefore, the dielectric constant of a liquid can be evaluated using capacitance detection values, and further, the hazard level of the liquid can be determined using the dielectric constant of the liquid. The processing circuit 202 acquires different near-end and far-end capacitance detection values. Using these values, the dielectric constant of the liquid filled in the non-metallic container 10 is determined. Based on the dielectric constant, the hazard level of the liquid is determined. The far-end plate 204 and the near-end plate 203 correspond to different positions on the non-metallic container 10, i.e., different capacitance detection points are set at different positions. Detection at different positions on the non-metallic container 10 reduces or avoids the influence of factors such as the degree of dent or thickness of the container, making the detection results more accurate and improving product performance.

[0108] Figure 9 The diagram shown is a flowchart of another embodiment of the liquid detection method of this application. Figure 9 As shown, step S2 includes steps S11-S12 and step S21. Step S21 is executed after step S12.

[0109] Step S11: Determine the difference between the near-end capacitance detection value and the near-end parasitic capacitance value of the near-end capacitor 207 to obtain the relative value of the near-end capacitance of the near-end capacitor 207. In this step, the near-end parasitic capacitance value is the inherent capacitance value between the near-end plate 203 and the ground plate 205 of the near-end capacitor 207 when there is no test object (e.g., no non-metallic can 10). This near-end parasitic capacitance value is used to represent the capacitance value from the near-end capacitor 207 itself without the influence of other dielectric constants, and is related to the dimensions between the near-end plate 203 and the ground plate 205 of the near-end capacitor 207. The near-end capacitance detection value is the capacitance value of the near-end capacitor 207 when liquid is filled in the non-metallic can 10. The near-end capacitance detection value is used to represent the sum of the inherent capacitance value of the near-end capacitor 207 and the liquid capacitance value when liquid is filled in the non-metallic can 10, affected by the dielectric constant of the liquid.

[0110] Step S12: Determine the difference between the far-end capacitance detection value and the far-end parasitic capacitance value of the far-end capacitor 208 to obtain the relative value of the far-end capacitance of the far-end capacitor 208. In this step, the far-end parasitic capacitance value is the capacitance value of the far-end capacitor 208 itself when there is no test object (e.g., no non-metallic can 10). This far-end parasitic capacitance value represents the inherent capacitance value between the far-end plate 204 and the ground plate 205 of the far-end capacitor 208, unaffected by other dielectric constants, and is related to the dimensions between the far-end plate 204 and the ground plate 205 of the far-end capacitor 208. The far-end capacitance detection value is the capacitance value of the far-end capacitor 208 when liquid is filled in the non-metallic can 10. This far-end capacitance detection value represents the sum of the inherent capacitance value of the far-end capacitor 208 and the liquid capacitance value when liquid is filled in the non-metallic can 10, affected by the dielectric constant of the liquid.

[0111] Step S21: Determine whether the liquid filled in the non-metallic container is a hazardous liquid based on the relative values ​​of the near-end capacitance and the far-end capacitance. In this step, the relative value of the near-end capacitance is obtained by the difference between the detected near-end capacitance value and the near-end parasitic capacitance value, and the relative value of the far-end capacitance is obtained by the difference between the detected far-end capacitance value and the far-end parasitic capacitance value. This reduces the influence of the capacitance values ​​of the near-end and far-end capacitors themselves on the determination of hazardous liquids, making the detection results more accurate.

[0112] Figure 10 The diagram shown is a flowchart of another embodiment of the liquid detection method of this application. Figure 10 As shown, step S21 includes step S211. Step S211 includes steps S212-S213. Steps S212 and S213 are executed after step S211. Wherein,

[0113] Step S211: Determine whether the liquid filled in the non-metallic container is a hazardous liquid based on the ratio of the relative value of the near-end capacitance to the relative value of the far-end capacitance.

[0114] In this embodiment, Cap Near Subtract Cap Near寄生 ΔCap is obtained Near ;Cap Far Subtract Cap Far寄生 ΔCap is obtained Far Among them, Cap Near寄生 The near-end parasitic capacitance value, ΔCap, is used to represent the near-end capacitance 207. Near Used to represent the relative value of the near-end capacitance 207. Far寄生 ΔCap is used to represent the far-end parasitic capacitance value of far-end capacitor 208. Far Used to represent the relative value of the far-end capacitance of the far-end capacitor 208.

[0115] Combining formulas (1) and (2) above, ΔCap Near ΔCap Far Dividing them yields formula (3);

[0116]

[0117] During the testing process, for the same non-metallic container 10, its air (ε) air ), tank (ε) bottle ), and boards (ε FR4 Given a given condition, the composite dielectric constant of the liquid being tested is primarily related to the liquid's dielectric constant (ε). liquid Related to ΔCap. Near ΔCap Far The value obtained by division is positively correlated with the ratio between the near-end capacitance detection value of near-end capacitor 207 and the near-end capacitance detection value of far-end capacitor 208, that is, it obtains the value related to the liquid dielectric constant (ε). liquid The relevant functions serve as the basis for determining whether the liquid being tested is hazardous or non-hazardous. This setup simplifies the detection method and increases accuracy, reducing or eliminating the influence of factors such as the degree of dents or thickness of the tank, thus preventing false alarms and missed detections and improving product performance.

[0118] Further, after step S211, the controller 209 determines the ratio of the relative value of the near-end capacitor to the relative value of the far-end capacitor, and executes steps S212 and S213. Wherein,

[0119] Step S212: If the ratio does not reach the danger threshold, the liquid filled in the non-metallic container is determined to be a non-hazardous liquid.

[0120] Step S213: If the ratio reaches the danger threshold, the liquid filled in the non-metallic container is determined to be a dangerous liquid.

[0121] In this embodiment, for example, the hazard threshold is 1.6. When the detected ratio is greater than 1.6, the liquid filled in the non-metallic container 10 is determined to be a hazardous liquid. When the detected ratio is less than 1.6, the liquid filled in the non-metallic container 10 is determined to be a non-hazardous liquid. Different liquids have different hazard thresholds. This hazard threshold can be obtained through extensive data measurement and stored in the controller 209. It can be retrieved at any time when needed by the controller 209. Thus, it is not limited to detecting only one type of liquid, but can also detect the hazard of different liquids, with a wider range of applications and greater scalability.

[0122] Figure 11 This is a flowchart illustrating the steps of another embodiment of the liquid detection method of this application. Figure 11As shown, the liquid detection method provided in this application embodiment further includes:

[0123] Step S111: When there is no test object, obtain the capacitance value of the near-end capacitor 207 as the near-end parasitic capacitance value. This step needs to be performed when there is no test object, such as when there is no non-metallic can 10.

[0124] Step S112: Obtain the near-end oscillation frequency of the near-end capacitor 207 when the non-metallic container 10 is filled with liquid. This step needs to be performed when the non-metallic container 10 is filled with liquid. (Combined with...) Figures 2-4 and Figure 11 As shown, the first conversion circuit 210 is used to obtain the near-end vibration frequency of the near-end capacitor 207 when the non-metallic container 10 is filled with liquid. The specific circuit structure can be found in the description above and will not be repeated here.

[0125] Step S113: Determine the proximal capacitance detection value based on the proximal vibration frequency. Combined with... Figures 2-4 and Figure 11 As shown, the controller 209 determines the near-end capacitance detection value of the near-end capacitor 207 based on the near-end vibration frequency. In the above embodiment, the detection method for this near-end parasitic capacitance value is the same as the method for detecting the near-end capacitance value. The main difference is that the near-end parasitic capacitance value needs to be detected when the non-metallic tank 10 is empty, while the near-end capacitance detection value needs to be detected when the non-metallic tank 10 contains a certain volume of liquid.

[0126] Figure 12 This is a flowchart illustrating the steps of another embodiment of the liquid detection method of this application. Figure 12 As shown, the liquid detection method provided in this application embodiment further includes:

[0127] Step S121: When there is no test object, obtain the capacitance value of the remote capacitor as the remote parasitic capacitance value. This step needs to be performed when there is no test object, for example, when there is no non-metallic can 10.

[0128] Step S122: Obtain the distal oscillation frequency of the distal capacitor 208 when the non-metallic container is filled with liquid. This step needs to be performed when the non-metallic container 10 is filled with liquid. (Combined with...) Figures 2-4 and Figure 12 As shown, the second conversion circuit 211 is used to obtain the distal vibration frequency of the distal capacitor 208 when the non-metallic container 10 is filled with liquid. The specific circuit structure can be found in the description above and will not be repeated here.

[0129] Step S123: Determine the remote capacitance detection value based on the remote vibration frequency. Combined with... Figures 2-4 and Figure 12As shown, the controller 209 determines the near-end capacitance detection value of the far-end capacitor 208 based on the far-end vibration frequency. In the above embodiment, the detection method for the far-end parasitic capacitance value is the same as the method for detecting the far-end capacitance value. The main difference is that the far-end parasitic capacitance value needs to be detected when the non-metallic tank 10 is empty, while the far-end capacitance detection value needs to be detected when the non-metallic tank 10 contains a certain volume of liquid.

[0130] Combination Figures 8 to 12 As shown, after the test procedure begins, the near-end capacitor 207 and the far-end capacitor 208 are first calibrated to obtain the near-end parasitic capacitance value of the near-end capacitor 207 and the far-end parasitic capacitance value of the far-end capacitor 208. This near-end parasitic capacitance value represents the capacitance value originating from the near-end capacitor 207 itself, unaffected by other dielectric constants. Similarly, the far-end parasitic capacitance value represents the capacitance value originating from the far-end capacitor 208 itself, unaffected by other dielectric constants. These near-end and far-end parasitic capacitance values ​​are obtained in advance without the test object and can be stored in the controller 209 for retrieval when calibration is required.

[0131] The near-end and far-end vibration frequencies are then detected separately when the non-metallic can 10 is filled with liquid. The first conversion circuit 210 and the second conversion circuit 211 are used for reverse derivation to obtain the near-end and far-end capacitance detection values ​​when the non-metallic can 10 is filled with liquid. Then, the difference between the near-end parasitic capacitance value and the near-end capacitance detection value is used to obtain the near-end relative capacitance value. Similarly, the difference between the far-end parasitic capacitance value and the far-end capacitance detection value is used to obtain the far-end relative capacitance value. The near-end relative capacitance value is divided by the far-end relative capacitance value, and compared with a danger threshold. The safety of the liquid is determined based on the comparison result. The far-end plate 204 and the near-end plate 203 correspond to different positions on the non-metallic can 10, i.e., different capacitance detection points are set at different positions. Detecting different positions on the non-metallic can reduces or avoids the influence of factors such as the degree of dent or thickness of the can, making the detection results more accurate and improving product performance.

[0132] The execution operations shown in the above figures are used to explain the liquid detection method provided in the embodiments of this application, but should not be construed as a specific limitation on the embodiments of this application. Liquids can be detected through a reasonable combination of various implementation methods.

[0133] In some embodiments, the controller may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor, or the controller may be any conventional processor. Further details will not be elaborated here.

[0134] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0135] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A liquid detection device, characterized in that, The liquid detection equipment is used to detect whether the liquid filled in the non-metallic container is a hazardous liquid; The liquid detection device includes: A capacitor plate includes a near-end plate, a far-end plate, and a ground plate located in the same plane and spaced apart from each other, wherein the near-end plate is positioned closer to the ground plate than the far-end plate; the near-end plate and the ground plate form a near-end capacitor, and the far-end plate and the ground plate form a far-end capacitor; and The processing circuit is electrically connected to the near-end capacitor and the far-end capacitor. The processing circuit includes a controller, which is used to acquire the near-end capacitor detection value and the far-end capacitor detection value, and determine whether the liquid filled in the non-metallic tank is a hazardous liquid based on the near-end capacitor detection value and the far-end capacitor detection value.

2. The liquid detection device according to claim 1, characterized in that, The controller is used to determine the difference between the near-end capacitance detection value and the near-end parasitic capacitance value of the near-end capacitor to obtain the near-end capacitance relative value of the near-end capacitor, and to determine the difference between the far-end capacitance detection value and the far-end parasitic capacitance value of the far-end capacitor to obtain the far-end capacitance relative value of the far-end capacitor; based on the near-end capacitance relative value and the far-end capacitance relative value, it is determined whether the liquid filled in the non-metallic tank is a hazardous liquid.

3. The liquid detection device according to claim 2, characterized in that, The controller is used to determine whether the liquid filled in the non-metallic tank is a hazardous liquid based on the ratio of the relative value of the near-end capacitance to the relative value of the far-end capacitance.

4. The liquid detection device according to claim 3, characterized in that, The controller is used to determine that the liquid filled in the non-metallic container is a non-hazardous liquid if the ratio does not reach the danger threshold; or, if the ratio reaches the danger threshold, to determine that the liquid filled in the non-metallic container is a hazardous liquid.

5. The liquid detection device according to claim 2, characterized in that, The controller is also configured to acquire the capacitance value of the near-end capacitor as the near-end parasitic capacitance value when there is no test object, and to acquire the capacitance value of the far-end capacitor as the far-end parasitic capacitance value.

6. The liquid detection device according to claim 2, characterized in that, The processing circuit further includes a conversion circuit, which comprises a first conversion circuit and a second conversion circuit. The first conversion circuit is electrically connected to the proximal capacitor and the controller, and the second conversion circuit is electrically connected to the distal capacitor and the controller. The first conversion circuit is used to acquire the proximal vibration frequency of the proximal capacitor when the non-metallic container is filled with liquid, and the controller is used to determine the proximal capacitor detection value based on the proximal vibration frequency. The second conversion circuit is used to acquire the distal vibration frequency of the distal capacitor when the non-metallic container is filled with liquid, and the controller is used to determine the distal capacitor detection value based on the distal vibration frequency.

7. The liquid detection device according to claim 6, characterized in that, The conversion circuit includes a NOT gate element and an oscillation circuit. The input terminal of the NOT gate element is electrically connected to the near-end capacitor or the far-end capacitor. The input terminal of the oscillation circuit is electrically connected to the output terminal of the NOT gate element. The controller is electrically connected to the output terminal of the oscillation circuit.

8. The liquid detection device according to claim 1, characterized in that, The proximal electrode, the distal electrode, and the ground electrode each include finger-shaped capacitor plates, and each finger-shaped capacitor plate includes a main body and a plurality of spaced fingers connected to the main body.

9. The liquid detection device according to claim 8, characterized in that, The proximal electrode plate includes a proximal electrode plate body, a plurality of first proximal fingers disposed on one side of the proximal electrode plate body, and a plurality of second proximal fingers disposed on the other side of the proximal electrode plate body. The first proximal fingers extend from the proximal electrode plate body toward the ground electrode plate, and the second proximal fingers extend from the proximal electrode plate body toward the distal electrode plate. The grounding electrode plate includes a grounding electrode plate body and a plurality of first grounding fingers disposed on one side of the grounding electrode plate body. The first grounding fingers extend from the grounding electrode plate body toward the first proximal fingers and are arranged to intersect with the first proximal fingers. The distal electrode plate includes a distal electrode plate body and a plurality of first distal fingers disposed on one side of the distal electrode plate body. The first distal fingers extend from the distal electrode plate body toward the side of the second proximal fingers and are arranged to intersect with the second proximal fingers.

10. The liquid detection device according to claim 9, characterized in that, The grounding electrode plate also includes a plurality of second grounding fingers disposed on the other side of the grounding electrode plate body, the second grounding fingers extending from the grounding electrode plate body toward the side away from the first proximal finger; and / or The distal electrode plate also includes a plurality of second distal fingers disposed on the other side of the distal electrode plate body, the second distal fingers extending from the distal electrode plate body toward the side opposite to the second proximal fingers.

11. The liquid detection device according to claim 1, characterized in that, The proximal electrode plate has a rectangular or spiral structure; and / or The grounding electrode plate is a rectangular or spiral structure; and / or The distal electrode plate has a rectangular or spiral structure; and / or The liquid detection device is a handheld liquid detection device.

12. A liquid detection method, characterized in that, The liquid detection device includes a capacitor plate, which comprises a near-end plate, a far-end plate, and a ground plate located in the same plane and spaced apart from each other. The near-end plate is positioned closer to the ground plate than the far-end plate. The near-end plate and the ground plate form a near-end capacitor, and the far-end plate and the ground plate form a far-end capacitor; The liquid detection method includes: Obtain the near-end capacitance detection value of the near-end capacitor and the far-end capacitance detection value of the far-end capacitor. and Based on the near-end capacitance detection value and the far-end capacitance detection value, it is determined whether the liquid filled in the non-metallic tank is a hazardous liquid.

13. The liquid detection method according to claim 12, characterized in that, The step of determining whether the liquid filled in the non-metallic container is a hazardous liquid based on the near-end capacitance detection value and the far-end capacitance detection value includes: The difference between the near-end capacitance detection value and the near-end parasitic capacitance value of the near-end capacitor is determined to obtain the near-end capacitance relative value of the near-end capacitor. The difference between the detected value of the far-end capacitance of the far-end capacitor and the value of the far-end parasitic capacitance of the far-end capacitor is determined to obtain the relative value of the far-end capacitance of the far-end capacitor. Based on the relative values ​​of the near-end capacitance and the far-end capacitance, it is determined whether the liquid filled in the non-metallic container is a hazardous liquid.

14. The liquid detection method according to claim 13, characterized in that, The step of determining whether the liquid filled in the non-metallic container is a hazardous liquid based on the relative values ​​of the near-end capacitance and the far-end capacitance includes: The ratio of the relative value of the near-end capacitance to the relative value of the far-end capacitance is used to determine whether the liquid filled in the non-metallic container is a hazardous liquid.

15. The liquid detection method according to claim 14, characterized in that, The step of determining whether the liquid filled in the non-metallic container is a hazardous liquid based on the ratio of the relative value of the near-end capacitance to the relative value of the far-end capacitance includes: If the ratio does not reach the danger threshold, the liquid filled in the non-metallic container is determined to be a non-hazardous liquid; or If the ratio reaches the danger threshold, the liquid filled in the non-metallic container is determined to be a dangerous liquid.

16. The liquid detection method according to claim 13, characterized in that, The method further includes: When there is no test object, the capacitance value of the near-end capacitance is obtained and used as the near-end parasitic capacitance value. When there is no object to be tested, the capacitance value of the far end capacitor is obtained and used as the far end parasitic capacitance value. The step of obtaining the near-end capacitance detection value of the near-end capacitor and the far-end capacitance detection value of the far-end capacitor includes: Obtain the proximal oscillation frequency of the proximal capacitor when the non-metallic container is filled with liquid; The proximal capacitance detection value is determined based on the proximal vibration frequency; Obtain the distal vibration frequency of the distal capacitor when the non-metallic container is filled with liquid; The distal capacitance detection value is determined based on the distal vibration frequency.

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