Weighing sensor with moisture-proof strain gauge and weighing system

Abstract

The utility model provides a kind of weighing sensor and weighing system with moisture-proof strain gauge, and weighing sensor includes elastomer, at least one step type strain gauge, water vapor barrier film, at least one strain area is provided on the elastomer, ladder type accommodating cavity is provided on the strain area, the step type strain gauge is fixed in the ladder type accommodating cavity, the water vapor barrier film is fixed above the accommodating cavity, completely covers the accommodating cavity. The utility model designs ladder type groove or support structure at the strain gauge sticking place of resistance strain type load sensor elastomer, as the accommodation space of strain gauge or strain gauge and water vapor barrier film, reduce or avoid the stress of strain gauge edge when water vapor barrier film is installed. Strain gauge is designed as the step type of covering layer length and width less than base length and width, reduce the stress of strain gauge edge when water vapor barrier film is installed, prevent the cracking of water vapor barrier film, avoid affecting water vapor barrier effect.

Description

Technical Field

[0001] This utility model relates to the field of weighing and measurement, and in particular to a weighing sensor and weighing system with a moisture-proof strain gauge. Background Technology

[0002] In load cells, strain gauges are typically made of a substrate of polymer or polymer composite material, a high-sensitivity wire grid, and adhesive, and a cover layer is added on top of the wire grid to protect the core component.

[0003] However, the polymers and adhesives used in the substrate and capping layer are rich in polar groups and lack the dense structure of metals or ceramics, making them highly hygroscopic. This leads to volume expansion, decreased adhesion, and changes in the elastic modulus, thus affecting the measurement accuracy of the strain gauge. For example, in high humidity environments, key indicators such as no-load output (zero point), full-scale output, and creep of non-welded, sealed resistance strain gauge load sensors will drift, significantly reducing reliability.

[0004] To suppress water vapor penetration, a water vapor barrier film can be applied to the surface of the strain gauge fixed to the strain region of the metallic elastomer. The barrier layer can be deposited directly on the strain gauge surface using methods such as physical deposition (PVD), chemical vapor deposition (CVD), or atomic layer deposition (ALD), depositing metal, inorganic ceramic, or inorganic-organic composite nanolayers / nanolayers. Alternatively, the barrier layer can be deposited on a plastic film first, and then the film can be adhered to the strain gauge surface.

[0005] However, when a plastic film with a pre-deposited water vapor barrier is directly pasted or pressed onto the surface of a strain gauge, the pressure and temperature during the bonding process often cause stress concentration at the edges of the strain gauge, leading to film cracking. Simultaneously, thermal expansion mismatch between different materials can easily induce nanoscale microcracks within the water vapor barrier film, causing its barrier performance to rapidly degrade. Even worse, uneven damage to the water vapor barrier films of multiple strain gauges on the same metallic elastomer can cause bridge circuit imbalance, turning the film, originally intended for protection, into a new cause of performance drift in the load sensor.

[0006] Therefore, the inventors of this application have designed a weighing sensor and weighing system with a moisture-proof strain gauge in order to overcome the above-mentioned technical problems. Utility Model Content

[0007] The technical problem to be solved by this utility model is to overcome the defect that the water vapor barrier film in the prior art is prone to cracking at the edge of the strain gauge, which reduces the moisture resistance of the strain gauge, and to provide a weighing sensor and weighing system with a moisture-proof strain gauge.

[0008] The present invention solves the above-mentioned technical problems through the following technical solution:

[0009] A load cell with a moisture-proof strain gauge is characterized in that the load cell includes an elastic body, at least one stepped strain gauge, and a water vapor barrier film. The elastic body has at least one strain zone, and the strain zone has a stepped receiving cavity. The stepped strain gauge is fixed inside the stepped receiving cavity, and the water vapor barrier film is fixed above the receiving cavity, completely covering the receiving cavity.

[0010] According to one embodiment of the present invention, the stepped receiving cavity is a groove formed on the strain zone, and the groove has a stepped structure of at least two levels.

[0011] According to one embodiment of the present invention, a support structure is provided on the strain zone, and the stepped receiving cavity is formed between the support structure and the strain zone, wherein the support structure is a stepped structure with at least two levels.

[0012] According to one embodiment of the present invention, the stepped strain gauge includes a substrate, electrode pads, resistance strips, and a cover layer stacked from bottom to top. The electrode pads are connected to the resistance strips, and the width of the cover layer is smaller than the width of the substrate.

[0013] According to one embodiment of the present invention, the substrate of the base, the covering layer or the water vapor barrier film is a film made of polymer or polymer composite material.

[0014] According to one embodiment of the present invention, a water vapor barrier layer is formed on the substrate, the cover layer, or the upper, lower, or all outer surfaces of the water vapor barrier film.

[0015] According to one embodiment of the present invention, the water vapor barrier layer is applied to the substrate, the capping layer, or the water vapor barrier film using physical deposition, chemical vapor deposition, or atomic deposition methods.

[0016] According to one embodiment of the present invention, the water vapor barrier layer is a nano monolayer or a nano stack.

[0017] According to one embodiment of the present invention, the resistor strip is a metal wire grid resistor strip with a tortuous structure.

[0018] This utility model also provides a weighing system, characterized in that the weighing system includes a weighing sensor with a moisture-proof strain gauge as described above.

[0019] The positive and progressive effects of this utility model are as follows:

[0020] This utility model relates to a weighing sensor and weighing system with moisture-proof strain gauges. The strain gauge is designed with multi-level grooves at the bonding point of the strain gauge on the elastic body of the resistance strain gauge load sensor. This grooves serve as a space for the strain gauge or the strain gauge and the water vapor barrier film, reducing or avoiding stress on the edge of the strain gauge during the installation of the water vapor barrier film.

[0021] In addition, the strain gauge is designed as a stepped shape with the length and width of the cover layer being smaller than the length and width of the substrate. This reduces the stress on the edge of the strain gauge during the installation of the water vapor barrier film, prevents the water vapor barrier film from cracking, and avoids affecting the water vapor barrier effect. Attached Figure Description

[0022] The above and other features, properties and advantages of this utility model will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, in which the same reference numerals always denote the same features, wherein:

[0023] Figure 1 This is a schematic diagram of the structure of a weighing sensor with a moisture-proof strain gauge according to Embodiment 1 of the present invention.

[0024] Figure 2 This is a perspective view of a first embodiment of the weighing sensor with a moisture-proof strain gauge according to the present invention.

[0025] Figure 3 This is a schematic diagram of the structure of a second embodiment of the weighing sensor with a moisture-proof strain gauge according to this utility model.

[0026] Figure 4 This is a perspective view of a second embodiment of the weighing sensor with a moisture-proof strain gauge according to the present invention.

[0027] Figure 5 This is a top view of the stepped strain gauge in the weighing sensor with a moisture-proof strain gauge of this utility model.

[0028] Figure 6 for Figure 5 A sectional view taken along line BB.

[0029] Figure 7 This is a schematic diagram of the structure of the weighing sensor with moisture-proof strain gauges of this invention, in which a water vapor barrier layer is formed on the upper surface of the thin film.

[0030] Figure 8 This is a schematic diagram of the structure of the weighing sensor with moisture-proof strain gauges of this invention, in which water vapor barrier layers are formed on the upper and lower surfaces of the thin film.

[0031] Figure 9 This is a schematic diagram of the structure of the weighing sensor with moisture-proof strain gauges of this invention, in which a water vapor barrier layer is formed on all the outer surfaces of the thin film.

[0032] Figure 10This is a schematic diagram of scanning electron microscope images at different magnifications of the water vapor barrier layer on the surface of the strain gauge after the installation of the moisture-proof strain gauge weighing sensor of this utility model.

[0033] Figure 11 To avoid using the installation method shown in this utility model, the water vapor barrier layer is directly installed on the surface of the strain gauge on the weighing sensor. Schematic diagram of scanning electron microscope images of the edge area of ​​the strain gauge at different magnifications.

[0034] Figure 12 This is an experimental diagram illustrating the moisture barrier properties of the weighing sensor with a moisture-proof strain gauge according to this invention. Detailed Implementation

[0035] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0036] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Preferred embodiments of the present invention will now be described in detail, examples of which are shown in the drawings. Wherever possible, the same reference numerals will be used in all the drawings to denote the same or similar parts.

[0037] Furthermore, although the terminology used in this invention is selected from commonly known and used terms, some terms mentioned in this specification may have been selected by the applicant in his or her judgment, and their detailed meanings are explained in the relevant sections of the description herein.

[0038] Furthermore, it is required that this utility model be understood not only through the actual terminology used, but also through the meaning implied by each term.

[0039] Example 1:

[0040] like Figure 1 and Figure 2 As shown, this utility model discloses a weighing sensor with a moisture-proof strain gauge. By setting a receiving cavity with a water vapor barrier function in the strain gauge pasting area on the surface of the load sensor, it is used to adapt the installation of the strain gauge and the water vapor barrier film, thereby improving the reduced water vapor barrier effect caused by the edge stress and thermal expansion difference of the strain gauge, as well as the drift of the metering performance of the non-welded sealed load sensor in a humid environment.

[0041] The load cell includes an elastic body 10, at least one stepped strain gauge 20, and a water vapor barrier film 30. At least one strain zone 11 is provided on the elastic body 10, and a stepped receiving cavity A is provided on the strain zone 11. The stepped strain gauge 20 is fixed inside the stepped receiving cavity A. The number of stepped receiving cavities A is determined according to the number of strain gauges 20 used in the load cell.

[0042] For example, in this embodiment, the stepped receiving cavity A is configured as a groove formed in the strain zone 11, the groove having a stepped structure of at least two levels. Figure 1 As shown, the groove is configured with two levels as an example, but it can also have a structure with more than two levels. The strain gauge 20 is preferably bonded using adhesive 40.

[0043] A moisture barrier film 30 is fixed above the receiving cavity A. For example, the moisture barrier film 30 is fixed to the upper groove (i.e., the upper opening of the receiving cavity A) using adhesive and completely covers the bottom groove (i.e., the receiving cavity A).

[0044] Here, the adhesive 40 used to adhere the moisture barrier film 30 must completely cover the adhesive surface of the moisture barrier film 30.

[0045] In this design, the strain gauge and the thin film are surrounded by metal, which further enhances the moisture-proof effect. The use of stepped strain gauges can further reduce edge stress.

[0046] like Figure 5 and Figure 6 As shown, in this embodiment, the stepped strain gauge 20 preferably includes a substrate 21, electrode pads 22, resistance strips 23, and a cover layer 24 stacked from bottom to top. The electrode pads 22 are connected to the resistance strips 23, and the resistance strips 23 are preferably metal wire grid resistance strips with a tortuous structure.

[0047] To reduce the stress at the edge of the strain gauge 20 when covered by the water vapor barrier film 30, the width of the covering layer 24 is smaller than the width of the substrate 21. After being stacked and molded, this structure forms a stepped structure that is narrower at the top and wider at the bottom.

[0048] like Figure 7 As shown, the substrate of the substrate 21, the capping layer 24, or the water vapor barrier film 30 is preferably a thin film C made of polymer or polymer composite material. A water vapor barrier layer 50 is formed on the upper surface of the substrate 21, the capping layer 24, or the water vapor barrier film 30. Here, the water vapor barrier layer 50 is preferably coated on the upper surface of the substrate 21, the capping layer 24, or the water vapor barrier film 30 by physical deposition, chemical vapor deposition, or atomic deposition methods, referred to in this application as the coated substrate 21, the coated capping layer 24, or the coated water vapor barrier film 30.

[0049] like Figure 8 As shown, in another embodiment, the water vapor barrier layer 50 is preferably coated on the upper and lower surfaces of the substrate 21, the capping layer 24, or the water vapor barrier film 30 using physical deposition, chemical vapor deposition, or atomic deposition methods, referred to in this application as the coated substrate 21, the coated capping layer 24, or the coated water vapor barrier film 30.

[0050] like Figure 9 As shown, in another embodiment, the water vapor barrier layer 50 is preferably applied to all outer surfaces of the substrate 21, the capping layer 24, or the water vapor barrier film 30 using physical deposition, chemical vapor deposition, or atomic deposition methods, referred to herein as the coated substrate 21, the coated capping layer 24, or the coated water vapor barrier film 30.

[0051] Here, the polymer used as the substrate for making the base layer 21, the capping layer 24, or the moisture barrier film 30 may preferably include, but is not limited to, polyimide, polyetheretherketone, polyethylene terephthalate, phenolic resin, epoxy resin, and derivatives of the above polymers. The polymer composite material may preferably include, but is not limited to, the above polymers and their derivatives modified with polymer fibers such as carbon nanotubes, carbon fibers, graphene, carbon dots, and carbon black; ceramic materials such as alumina, zirconium oxide, titanium oxide, silicon oxide, silicon nitride, aluminum nitride, and boron nitride; minerals such as talc, montmorillonite, kaolin, diatomaceous earth, and mica; and glass fiber.

[0052] The moisture barrier layer 50 is preferably a nano-monolayer or a nano-stack. The chemical composition of the nano-monolayer or stack includes, but is not limited to, moisture-proof components such as metals, inorganic ceramics, and inorganic-organic composites. Specifically, the nano-monolayer or nano-stack refers to a nano-monolayer or nano-stack deposited using methods such as physical deposition, chemical vapor deposition, or atomic deposition, containing one or more of the following ceramic materials: alumina, zirconium oxide, titanium oxide, silicon oxide, silicon nitride, silicon carbide, and boron nitride. The ceramic-organic nanolayer refers to a ceramic-organic nanolayer doped with organic components. The metal coating refers to a metal coating such as aluminum or aluminum alloy. The deposition temperature is generally higher than the glass transition temperature of the polymer film to reduce thermal expansion stress between the moisture barrier layer and the polymer film.

[0053] Furthermore, the moisture barrier layer 50 is deposited directly on the outer surface of the strain gauge 20 using physical deposition, chemical vapor deposition, or atomic deposition methods, while creating uncoated openings 25 to ensure the solderability of the electrode pads 22, thus obtaining a moisture-proof strain gauge.

[0054] Typically, the substrate 21 and the capping layer 24 of the strain gauge 20 are made of the same polymer substrate. The strain gauge 20 and the moisture barrier layer 30 can be made of the same or different polymer substrates. It should be noted that when the strain gauge 20 and the moisture barrier layer 30 are made of the same polymer substrate, a better improvement effect can be obtained because their thermal expansion is similar.

[0055] In addition, the adhesives 40 applicable in this embodiment include, but are not limited to, hot melt adhesives, thermosetting, room temperature curing or light curing epoxy resins, phenolic resins, acrylates, polyurethanes, silicones, and adhesives based on the above polymer matrix modified with hygroscopic fillers such as metal oxides, minerals or fibers.

[0056] Except for the strain gauge and the water vapor barrier film 30 made of opaque polymer or polymer composite substrate, which cannot be fixed with light-curing adhesives, the strain gauge 20 and the coated water vapor barrier film 30 can be installed using the same or different adhesives, and can be cured simultaneously or sequentially depending on the curing conditions of the adhesives. Appropriate pressure must be applied during the curing process to eliminate air bubbles in the adhesive layer and ensure uniform bonding.

[0057] The adhesive can be applied separately, or it can be applied to the strain gauge and the coated water vapor barrier film 30 by spraying, spin coating, scraping, or rolling to create an adhesive-backed strain gauge and a coated film. The adhesive used to bond the coated water vapor barrier film 30 must completely cover the film bonding surface.

[0058] Example 2:

[0059] like Figure 3 and Figure 4 As shown, this utility model discloses a weighing sensor with a moisture-proof strain gauge. By setting a receiving cavity with a water vapor barrier function in the strain gauge pasting area on the surface of the load sensor, it is used to adapt the installation of the strain gauge and the water vapor barrier film, thereby improving the reduced water vapor barrier effect caused by the edge stress and thermal expansion difference of the strain gauge, as well as the drift of the metering performance of the non-welded sealed load sensor in a humid environment.

[0060] The load cell includes an elastic body 10, at least one stepped strain gauge 20, and a water vapor barrier film 30. At least one strain zone 11 is provided on the elastic body 10, and a stepped receiving cavity A is provided on the strain zone 11. The stepped strain gauge 20 is fixed inside the stepped receiving cavity A. The number of stepped receiving cavities A is determined according to the number of strain gauges 20 used in the load cell.

[0061] For example, in this embodiment, a support structure 60 is provided on the strain zone 11, and the stepped receiving cavity A is formed between the stepped support structure 60 and the strain zone 11. The support structure has at least two levels of stepped structure. In this solution, the strain gauge and the water vapor barrier film are surrounded by support materials with water vapor barrier function, which can further enhance the moisture-proof effect. Figure 3 As shown, the support structure is configured with two levels, but it can also be configured with more than two levels. The strain gauges 20 are preferably bonded using adhesive 40.

[0062] Specifically, in this embodiment, the support structure 60 is preferably a stepped structure with moisture-proof function. This moisture-proof support structure is based on one or more of a thermosetting, room-temperature curing, or light-curing adhesive modified with hygroscopic fillers such as metal oxides, minerals, or fibers, and is printed around the bonding area of ​​the strain gauge 20 by means of screen printing or inkjet printing. After the primary moisture-proof support structure is formed, the strain gauge 20 is installed using adhesive 40. After the secondary support structure is formed, the moisture barrier film 30 is installed.

[0063] A moisture barrier film 30 is fixed above the receiving cavity A. For example, the moisture barrier film 30 is fixed to the upper groove (i.e., the upper opening of the receiving cavity A) using adhesive and completely covers the bottom groove (i.e., the receiving cavity A).

[0064] Here, the adhesive 40 used to adhere the moisture barrier film 30 must completely cover the adhesive surface of the moisture barrier film 30.

[0065] In this design, the strain gauge is surrounded by moisture-proof components, which further enhances the moisture-proof effect. The use of stepped strain gauges can further reduce edge stress.

[0066] like Figure 5 and Figure 6 As shown, in this embodiment, the stepped strain gauge 20 preferably includes a substrate 21, electrode pads 22, resistance strips 23, and a cover layer 24 stacked from bottom to top. The electrode pads 22 are connected to the resistance strips 23, and the resistance strips 23 are preferably metal wire grid resistance strips with a tortuous structure.

[0067] To reduce the stress at the edge of the strain gauge 20 when covered by the water vapor barrier film 30, the width of the covering layer 24 is smaller than the width of the substrate 21. After being stacked and molded, this structure forms a stepped structure that is narrower at the top and wider at the bottom.

[0068] like Figure 7 As shown, the substrate of the substrate 21, the capping layer 24, or the water vapor barrier film 30 is preferably a film made of polymer or polymer composite material. A water vapor barrier layer 50 is formed on the upper surface of the substrate 21, the capping layer 24, or the water vapor barrier film 30. Here, the water vapor barrier layer 50 is preferably coated on the upper surface of the substrate 21, the capping layer 24, or the water vapor barrier film 30 by methods such as physical deposition, chemical vapor deposition, or atomic deposition, and is referred to in this application as the coated substrate 21, the coated capping layer 24, or the coated water vapor barrier film 30.

[0069] like Figure 8As shown, in another embodiment, the water vapor barrier layer 50 is preferably coated on the upper and lower surfaces of the substrate 21, the capping layer 24, or the water vapor barrier film 30 using physical deposition, chemical vapor deposition, or atomic deposition methods, referred to in this application as the coated substrate 21, the coated capping layer 24, or the coated water vapor barrier film 30.

[0070] like Figure 9 As shown, in another embodiment, the water vapor barrier layer 50 is preferably applied to all outer surfaces of the substrate 21, the capping layer 24, or the water vapor barrier film 30 using physical deposition, chemical vapor deposition, or atomic deposition methods, referred to herein as the coated substrate 21, the coated capping layer 24, or the coated water vapor barrier film 30.

[0071] Here, the polymer used as the substrate for making the base layer 21, the capping layer 24, or the moisture barrier film 30 may preferably include, but is not limited to, polyimide, polyetheretherketone, polyethylene terephthalate, phenolic resin, epoxy resin, and derivatives of the above polymers. The polymer composite material may preferably include, but is not limited to, the above polymers and their derivatives modified with polymer fibers such as carbon nanotubes, carbon fibers, graphene, carbon dots, and carbon black; ceramic materials such as alumina, zirconium oxide, titanium oxide, silicon oxide, silicon nitride, aluminum nitride, and boron nitride; minerals such as talc, montmorillonite, kaolin, diatomaceous earth, and mica; and glass fiber.

[0072] The water vapor barrier layer 50 is preferably a nano-monolayer, a nano-layer stack, a ceramic-organic nanolayer, or a metal coating. The nano-monolayer or nano-layer stack refers to a nano-monolayer or nano-layer deposited with one or more ceramic materials such as alumina, zirconium oxide, titanium oxide, silicon oxide, silicon nitride, silicon carbide, and boron nitride through physical deposition, chemical vapor deposition, or atomic deposition. The ceramic-organic nanolayer refers to a ceramic-organic nanolayer doped with organic components. The metal coating refers to a metal coating such as aluminum or aluminum alloy. The deposition temperature is generally higher than the glass transition temperature of the polymer film to reduce the thermal expansion stress between the water vapor barrier layer and the polymer film.

[0073] Furthermore, the moisture barrier layer 50 is deposited directly on the outer surface of the strain gauge 20 using physical deposition, chemical vapor deposition, or atomic deposition methods, while creating uncoated openings 25 to ensure the solderability of the electrode pads 22, thus obtaining a moisture-proof strain gauge.

[0074] Typically, the substrate 21 and the capping layer 24 of the strain gauge 20 are made of the same polymer substrate. The strain gauge 20 and the moisture barrier layer 30 can be made of the same or different polymer substrates. It should be noted that when the strain gauge 20 and the moisture barrier layer 30 are made of the same polymer substrate, a better improvement effect can be obtained because their thermal expansion is similar.

[0075] In addition, the adhesives 40 applicable in this embodiment include, but are not limited to, hot melt adhesives, thermosetting, room temperature curing or light curing epoxy resins, phenolic resins, acrylates, polyurethanes, silicones, and adhesives based on the above polymer matrix modified with hygroscopic fillers such as metal oxides, minerals or fibers.

[0076] Except for the strain gauge and the water vapor barrier film 30 made of opaque polymer or polymer composite substrate, which cannot be fixed with light-curing adhesives, the strain gauge 20 and the coated water vapor barrier film 30 can be installed using the same or different adhesives, and can be cured simultaneously or sequentially depending on the curing conditions of the adhesives. Appropriate pressure must be applied during the curing process to eliminate air bubbles in the adhesive layer and ensure uniform bonding.

[0077] The adhesive can be applied separately, or it can be applied to the strain gauge and the coated water vapor barrier film 30 by spraying, spin coating, scraping, or rolling to create an adhesive-backed strain gauge and a coated film. The adhesive used to bond the coated water vapor barrier film 30 must completely cover the film bonding surface.

[0078] Based on the descriptions of Embodiments 1 and 2 above, the effects of the weighing sensor with moisture-proof strain gauges of this invention are as follows:

[0079] For example, consider a dual-hole parallel beam adhesive-sealed sensor with a capacity of 30kg and using 2024-T4 aluminum alloy elastomer. It has four strain gauge patch areas, each with two levels of grooves for mechanical protection: the total depth of the grooves is 50μm, and the length and width dimensions are slightly larger than the strain gauge body.

[0080] A thermosetting epoxy adhesive is used to simultaneously attach a nano-ceramic laminate film to the surface of the strain gauge, and then the entire assembly is cured. Preferably, the deposition temperature of the nano-ceramic laminate is higher than the thermosetting temperature of the epoxy adhesive.

[0081] like Figure 10 and Figure 11 As shown, no cracks were observed at the edge of the strain gauge in the scanning electron microscope image.

[0082] like Figure 12As shown, under test conditions of 40℃ and 85%RH, the full-scale output value of the sensor described in this invention changes by only -40ppm compared to normal temperature and humidity conditions, while the full-scale output value of the normal sensor without this invention changes by -203ppm. This demonstrates that the sensor described has excellent moisture barrier properties.

[0083] In addition, this utility model also provides a weighing system, which includes a weighing sensor with a moisture-proof strain gauge as described above.

[0084] In summary, this utility model relates to a weighing sensor and weighing system with a moisture-proof strain gauge. Multi-level grooves are designed at the strain gauge attachment point of the elastic body of the resistance strain gauge load sensor to serve as a receiving space for the strain gauge or the strain gauge and the water vapor barrier film, reducing or avoiding stress on the strain gauge edges during water vapor barrier film installation. Furthermore, the strain gauge is designed as a stepped shape with the length and width of the covering layer smaller than the length and width of the base, further reducing stress on the strain gauge edges during water vapor barrier film installation, preventing cracking of the water vapor barrier film, and avoiding affecting the water vapor barrier effect.

[0085] For those skilled in the art, the above disclosure is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application and therefore remain within the spirit and scope of the exemplary embodiments of this application.

[0086] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0087] Similarly, it should be noted that, in order to simplify the description of the embodiments disclosed in this application and thus aid in the understanding of one or more embodiments of the invention, the foregoing description of the embodiments of this application sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this disclosure method does not imply that the subject matter of this application requires more features than those mentioned in the claims. In fact, the embodiments have fewer features than all the features of a single embodiment disclosed above. Some embodiments use numbers describing the number of components or attributes; it should be understood that such numbers used in the description of embodiments are modified in some examples by the terms "approximately," "about," or "generally."

[0088] While specific embodiments of this utility model have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model, but all such changes and modifications fall within the scope of protection of this utility model.

Claims

1. A weighing sensor with a moisture-proof strain gauge, characterized in that, The weighing sensor includes an elastomer, at least one stepped strain gauge, and a water vapor barrier film. The elastomer has at least one strain zone, and the strain zone has a stepped receiving cavity. The stepped strain gauge is fixed inside the stepped receiving cavity, and the water vapor barrier film is fixed above the receiving cavity, completely covering the receiving cavity.

2. The weighing sensor with a moisture-proof strain gauge as described in claim 1, characterized in that, The stepped receiving cavity is a groove opened on the strain zone, and the groove has a stepped structure of at least two levels.

3. The weighing sensor with a moisture-proof strain gauge as described in claim 1, characterized in that, A support structure is provided on the strain zone, and the stepped receiving cavity is formed between the support structure and the strain zone. The support structure has at least two stepped levels.

4. The weighing sensor with a moisture-proof strain gauge as described in claim 1, characterized in that, The stepped strain gauge includes a substrate, electrode pads, resistance strips, and a cover layer stacked from bottom to top. The electrode pads are connected to the resistance strips, and the width of the cover layer is smaller than the width of the substrate.

5. The weighing sensor with a moisture-proof strain gauge as described in claim 4, characterized in that, The substrate, the cover layer, or the water vapor barrier film is a film made of polymer or polymer composite material.

6. The weighing sensor with a moisture-proof strain gauge as described in claim 4, characterized in that, A water vapor barrier layer is formed on the substrate, the cover layer, or the upper, lower, or all outer surfaces of the water vapor barrier film.

7. The weighing sensor with a moisture-proof strain gauge as described in claim 6, characterized in that, The water vapor barrier layer is applied to the substrate, the capping layer, or the water vapor barrier film using physical deposition, chemical vapor deposition, or atomic deposition methods.

8. The weighing sensor with a moisture-proof strain gauge as described in claim 6, characterized in that, The water vapor barrier layer is a single nanolayer or a stack of nanolayers.

9. The weighing sensor with a moisture-proof strain gauge as described in claim 4, characterized in that, The resistor strip is a metal wire grid resistor strip with a tortuous structure.

10. A weighing system, characterized in that, The weighing system includes a weighing sensor with a moisture-proof strain gauge as described in any one of claims 1-9.

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