Linear impedance adjustable planar liquid leakage amount detection sensor
By setting up a staggered T-sheet structure with low resistance electrodes and high resistance conductive coatings on the sensor, the problems of low detection accuracy and easy corrosion in traditional sensors are solved, and accurate identification of liquid leakage is achieved and low cost and long-term use is achieved.
Patent Information
- Application Number
- CN202510895359.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-30
- Publication Date
- 2025-08-01
AI Technical Summary
The traditional planar liquid leakage detection sensor has low detection accuracy and cannot achieve linear relationship judgment of liquid leakage. The exposed electrode is prone to corrosion and failure, has a short service life and high cost, and needs to be replaced frequently, which is troublesome to operate.
A pair of low-resistance electrodes and gold-plated protective layers are used, combined with high-resistance conductive coating. The high-resistance conductive coating material is carbon oil or high-resistance silicone. It is applied to the substrate to cover the low-resistance electrode and gold-plated protective layer to form a staggered T-shaped thin sheet structure to achieve linear changes in the leakage area and equivalent resistance.
It realizes accurate identification of liquid leakage, reduces operation and maintenance costs, extends the use cycle, reduces product corrosion risks, simplifies operating procedures, and reduces usage costs.
Smart Images
Figure CN120403992A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of detection sensors, and particularly relates to a planar liquid leakage detection sensor with adjustable linear impedance. Background Art
[0002] Sensors are widely used in industry, especially in some high-precision equipment, computer rooms, etc. Among them, liquid leakage detection is a very important one. At present, many use planar liquid leakage detection sensors. The traditional planar liquid leakage detection sensor processes two low-resistance bare electrodes in the target detection area, such as printing two low-resistance conductive electrodes on FFC / or processing two bare immersion-gold electrodes on FPC. Finally, the electrodes are connected to the detection circuit board through wires. This traditional sensor structure can meet certain usage requirements, but there are also large defects. When the electrodes on the detection plane are contacted by liquid, an equivalent resistor will be generated. The characteristic of this resistor is non-linear. That is to say, as long as there is liquid on the plane, this resistor will immediately change from infinity to an equivalent resistance of about 200 - 500K. It is impossible to form a linear relationship between the leakage area and the resistance change, and it is impossible to accurately judge the liquid leakage amount. The detection accuracy is low. Moreover, the processing cost of the bare low-resistance layer on the sensor is high, and the materials are gold plating, immersion gold or silver plating, which are easy to corrode. When liquid leakage occurs for a long time, it will accelerate the electrolytic corrosion of the product, and ultimately accelerate the failure of the product. The service life is short, the usage cost is high, it needs to be frequently replaced, the operation is troublesome, and it cannot effectively meet the normal usage requirements.
[0003] The technical problem to be solved by the present invention is to provide a planar liquid leakage detection sensor with adjustable linear impedance, which has linear resistance change, can accurately judge the liquid leakage amount, has high detection accuracy, is not easy to corrode and fail, has a long service life, low usage cost, does not need to be frequently replaced, has simple operation, and can effectively meet the usage requirements. Summary of the Invention
[0004] To solve the problems that the prior art cannot form a linear relationship between the leakage area and the resistance change, cannot accurately judge the liquid leakage amount, has low detection accuracy, has high processing cost for the bare low-resistance layer on the sensor, the material is easy to corrode, the product is easy to fail, has a short service life, high usage cost, needs to be frequently replaced, the operation is troublesome, and cannot effectively meet the normal usage requirements, etc., the present invention adopts the following technical solutions: The present invention provides a planar liquid leakage detection sensor with adjustable linear impedance, including a substrate, a pair of low-resistance electrodes, a gold-plated protective layer, and a high-resistance conductive coating. The pair of low-resistance electrodes are respectively arranged at both ends of the substrate. The gold-plated protective layer is a pair of staggered T-shaped thin sheets. The high-impedance conductive coating is evenly applied on the substrate and completely covers the low-resistance electrodes and the gold-plated protective layer.
[0005] Preferably, the material of the high-resistance conductive coating is carbon oil or high-resistance silica gel.
[0006] The beneficial effects of the present invention are: by adding a high-resistance conductive coating, the leakage area and the equivalent resistance form a wide-range linear curve, which easily realizes the accurate identification of the leakage amount, and performs safety management according to the risk level, greatly reducing the operation and maintenance costs. The equipment operates reliably, and leakage of the high-resistance coating will not affect the product. It is not easy to corrode and fail, has a long service life, low cost, does not require frequent replacement, is simple to operate, and effectively meets the use requirements. BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Figure 1 This is a structural diagram of an embodiment of the present invention.
[0008] Figure 2 This is a diagram of the liquid resistance test model.
[0009] Figure 3 This is a diagram showing resistance of traditional products.
[0010] Figure 4 This is a diagram showing the resistance of the present invention.
[0011] Figure 5 It is a curve diagram of the change of leakage amount and resistance in the present invention. DETAILED DESCRIPTION
[0012] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
[0013] See also Figure 1 A planar liquid leakage detection sensor with adjustable linear impedance includes a substrate 1, a pair of low-resistance electrodes 2, a gold-plated protective layer 3 and a high-resistance conductive coating 4, wherein the pair of low-resistance electrodes 2 are respectively arranged at both ends of the substrate 1, and the gold-plated protective layer 3 is a pair of staggered T-shaped thin sheets. The high-resistance conductive coating 4 is evenly applied on the substrate 1 and completely covers the low-resistance electrode 2 and the gold-plated protective layer 3. A controllable high-resistance conductive layer is covered on the surface of the low-resistance electrode. In this way, liquid leakage at any point on the substrate plane will indirectly be connected in series with two high-impedance resistors, effectively limiting the impedance mutation phenomenon after the electrode contacts the liquid. In this way, the resistance of the entire detection plane will form a linear change characteristic of resistance / leakage amount in a large area with the amount of leakage, and this linear parameter can be customized by adjusting the square resistance of the high-resistance layer and the line spacing. The customized linear parameters can meet the specific usage requirements in different scenarios, and the scope of use is not limited.
[0014] Here, it is necessary to first introduce the liquid resistance test model, such as Figure 2As shown in the figure, it involves several parameters: \(R = ho*L / S\), where \(R\) is the equivalent resistance per unit area, \(ho\) is the resistivity of the liquid, \(L\) is the electrode spacing, and \(S\) is the electrode area. From the above calculation formula, it can be seen that the product structure \(L / S\) can change the resistance value. However, in the actual product design, due to the planar structure of the product, the electrodes can only be on one plane; \(L\) and \(S\) are restricted by physical conditions and cannot be adjusted to the ideal size according to the design goal. For example, if the spacing is too large, small liquid droplets cannot contact both electrodes simultaneously. \(ho\) is the resistivity of the coolant, and for different manufacturers' confidentiality levels, the resistivity cannot be adjusted either.
[0015] Traditional products, such as Figure 3 As shown in the figure, when there is liquid on the surface of the two bare electrodes above, an equivalent resistance will be generated. The two electrodes above are at both ends of these resistances. When there is no liquid, the resistance between the two electrodes is a high resistance, that is, infinity. Once there is liquid contacting both electrodes simultaneously, the resistance will quickly drop to the 100K level. When the area of the liquid contacting the two electrodes increases, the unit equivalent resistance is \(R_x = R_{Ln}\). For the product of this patent, the wire is made thinner, and then a high-resistance conductive layer is printed, sprayed, pasted, etc. on the wire. The high-resistance conductive layer is centered on the wire and has an area greater than \(N\) times that of the wire, which is equivalent to connecting the liquid resistances in series, thereby achieving the expansion of the linear region of the product and increasing the measurement range. Such as Figure 4 As shown in the figure, the electrical structure surface of the product of this patent can be equivalent to three resistances. The resistance directly above the wire is \(R_{mn}\), and the resistances on both sides of the wire are \(R_{an}=R_{bn}\). Therefore, when a small liquid droplet touches the edges of the two electrodes, the unit equivalent resistance \(R_x\) takes the maximum value, \(R_{x\_max}=(R_{mn}+R_{an}+R_{Ln}+R_{mn}+R_{bn})\). By adjusting the line width of the surface high layer, it can be achieved that \(R_{an}=R_{bn}\) is much larger than \(R_{mn}\). When a large amount of liquid leakage occurs, the loop resistance above the central electrode is the smallest, and the equivalent resistance is: \(R_{xmin}=(R_{mn}+R_{L}+R_{mn})\). The loop resistance at the electrode edge is the largest, and the equivalent resistance is: \(R_{x\_max}=(R_{mn}+R_{an}+R_{Ln}+R_{mn}+R_{bn})\). The actual equivalent resistance is between \(R_{xmin}\) and \(R_{xmax}\), and the equivalent resistance is: \(R_x=(R_{xmin}+R_{xmax}) / 2\). The total equivalent resistance is: \(1 / [1 / R_{X1}+1 / R_{X2}+…+1 / R_{Xn}]\).
[0016] After the above analysis, more detailed values can be obtained. After adding the high-resistance coating, if there is no dripping, the resistance between the electrodes is infinitely large. When there is one drop of water, the resistance between the electrodes is 20 - 25 MΩ. When there are N drops of water, the resistance between the electrodes is 100 - 200 KΩ. The leakage volume and the resistance are linearly related. For traditional products, when there is no dripping, the resistance between the electrodes is infinitely large. When there is one drop of water, the resistance between the electrodes is 200 - 500 KΩ. When there are N drops of water, the resistance between the electrodes is 200 - 500 KΩ. There is no obvious linear relationship between the leakage volume and the resistance. One drop of water is the same as a large amount of water drops, and it is impossible to accurately judge the leakage volume. The changes in the leakage volume and the resistance are as Figure 5 shown Figure 5 which shows the change curves of two cases of traditional and new products of this patent.
[0017] We can conduct experiments on traditional and new products of this patent. Assume that the equivalent resistance of the liquid unit RL: 200K. Take 100 units to analyze the curves of the new invention product and the traditional product as follows. Rmn: 200K, Ran = Rbn = 1000K, the equivalent resistance of the new product, fMix(n) = 1 / [n * 1 / (((Rmn + Ran + RLn + Rmn + Rbn)+(Rmn + RLn + Rmn)) / 2)] The equivalent resistance of the traditional product: f(n) = 1 / (n * (1 / 200)) RL(KΩ): 110, Rmn(KΩ): 200, Ran(KΩ): 10000, Rbn(KΩ): 10000.
[0018] By adding this high-resistance conductive layer, a wide-range linear curve of the leakage area and the equivalent resistance can be achieved, thus easily realizing the accurate identification of the leakage area (leakage volume). The staff can conduct safety management according to the risk level, greatly reducing the operation and maintenance cost and ensuring the reliable operation of the equipment. At the same time, after using the high-resistance layer on the surface, even if long-term leakage occurs, it will not affect the product and cause corrosion and failure. Due to the high-resistance characteristics of the surface material, the electrolytic corrosion current is limited and the product is hardly affected.
[0019] Among them, the material of the high-resistance conductive coating 4 is carbon oil or high-resistance silica gel. This carbon oil ink has high physical / chemical stability and is hardly oxidized and electrolytically corroded, improving the requirements for the product use environment and greatly reducing the product processing and manufacturing cost. Its material is not limited to this, and other materials that can achieve adjustable high impedance are also within the protection scope of this patent, such as high-resistance silica gel, conductive paint or conductive glue, as long as this characteristic can be satisfied.
[0020] The beneficial effects of the present invention are: by adding a high-resistance conductive coating, the leakage area and the equivalent resistance form a wide-range linear curve, which easily realizes the accurate identification of the leakage amount, and performs safety management according to the risk level, greatly reducing the operation and maintenance costs. The equipment operates reliably, and leakage of the high-resistance coating will not affect the product. It is not easy to corrode and fail, has a long service life, low cost, does not require frequent replacement, is simple to operate, and effectively meets the use requirements.
[0021] The above embodiments and drawings do not limit the product form and style of the present invention. Any appropriate changes or modifications made by ordinary technicians in the relevant technical field should be deemed to be within the patent scope of the present invention.
Claims
1. A planar liquid leakage detection sensor with adjustable linear impedance, characterized in that: It includes a substrate (1), a pair of low-resistance electrodes (2), a gold-plated protective layer (3), and a high-resistance conductive coating (4). The pair of low-resistance electrodes (2) are respectively arranged at both ends of the substrate (1). The gold-plated protective layer (3) is a pair of staggered T-shaped thin sheets. The high-impedance conductive coating (4) is evenly applied on the substrate (1) and completely covers the low-resistance electrodes (2) and the gold-plated protective layer (3).
2. The planar liquid leakage detection sensor with adjustable linear impedance according to claim 1, wherein: The material of the high-resistance conductive coating (4) is carbon oil or high-resistance silica gel.