A high-precision weighing evaporation instrument based on lever balance embedded installation

Abstract

The utility model discloses a kind of high-precision weighing evapotranspiration instruments of embedded installation based on lever balance, belong to evapotranspiration instrument technical field. Including fixed support, tray assembly is movably connected on fixed support, and evapotranspiration instrument experimental soil box is set on tray assembly, and weighing assembly is set below tray assembly;Force transmission pull rod is arranged between tray assembly and weighing assembly;Weighing assembly includes force measuring device, and force measuring device side rotatably connects with lever two, and lever two middle part is rotatably installed at the bottom of fixed support by support;Force transmission pull rod upper end is respectively connected with two lever one hinged connection, and force transmission pull rod lower end is movably connected with lever two. The utility model is through the cooperation of lever two and counterweight, substantially offset the initial weight of evapotranspiration instrument experimental soil box, so that force measuring device only needs to monitor the tiny weight change caused by soil evaporation, crop transpiration and rainfall / irrigation, avoid large load to influence sensor sensitivity, realize high-precision data acquisition.

Description

Technical Field

[0001] This utility model relates to the field of quasi-percolation instrument technology, and more specifically, to an embedded high-precision weighing quasi-percolation instrument based on lever balance. Background Technology

[0002] Lyopermeability is an important instrument for studying water exchange processes in the soil-plant-atmosphere continuum, and it is widely used in agricultural irrigation management, eco-hydrological research, and climate change impact assessment. Its core function is to quantify water transformation processes such as soil evaporation, plant transpiration, precipitation infiltration, and deep seepage by accurately measuring the weight changes of specific soil units, providing key data support for understanding the water cycle and formulating water-saving strategies.

[0003] Traditional lysimeters are mainly divided into two categories: weighing and non-weighing. Non-weighing lysimeters calculate water balance by measuring changes in soil moisture content or seepage, but their accuracy is low and they are difficult to capture short-term water dynamics. Weighing lysimeters, on the other hand, directly measure changes in soil weight, can reflect the water migration process in real time, and have a measurement accuracy down to the gram level, making them the preferred equipment for high-precision water research.

[0004] Currently, most mainstream gravimetric lysimeters employ direct weighing or single-lever amplification structures. Direct weighing lysimeters typically place the test chamber directly on the weighing sensor. While simple in structure, this results in a large sensor load, placing extremely high demands on sensor range and stability, and making it difficult to achieve high-precision measurements in large test chambers. Single-lever lysimeters amplify weight changes through the lever principle, reducing the sensor load; however, obtaining sufficient amplification often requires a long lever arm, leading to a large overall device size and high installation space requirements, especially in field test stations or greenhouse environments where space constraints are significant.

[0005] Meanwhile, existing lysimeters mostly use externally mounted test chambers, distributed vertically with the weighing structure, further increasing the equipment height. This not only poses a risk of instability but also makes them susceptible to external interference such as wind, affecting measurement accuracy. Furthermore, traditional equipment offers limited solutions to the contradiction between balancing the weight of the soil itself and monitoring moisture changes—if the focus is on balancing solid weight, the sensitivity is insufficient; if the focus is on increasing sensitivity, it struggles to adapt to the weight differences in soil textures, limiting its application under diverse testing conditions.

[0006] Therefore, developing a compact, easy-to-install lysimeter that combines high load capacity and high measurement accuracy has become a key technological requirement for resolving the current contradiction between equipment size and accuracy and expanding its application scenarios. In view of this, we propose an embedded, high-precision weighing lysimeter based on lever balance. Utility Model Content

[0007] The purpose of this invention is to provide an embedded high-precision weighing evaporator based on lever balance to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, this utility model provides the following technical solution: An embedded high-precision weighing lysimeter based on lever balance includes a fixed bracket, a tray assembly movably connected to the fixed bracket, a lysimeter test soil box mounted on the tray assembly, and a weighing component mounted below the tray assembly. The pallet assembly includes a suspended pallet, with force transmission plates at each of the four corners of the suspended pallet. Lever 1 is provided on the inner side of the upper part of the two opposing force transmission plates, and force transmission rod is provided on the inner end of the two levers 1 near the bottom. The weighing assembly includes a force measuring device, a lever two is rotatably connected to one side of the force measuring device, the middle part of the lever two is rotatably mounted on the bottom of the fixed bracket via a bracket, and a counterweight is provided at the other end of the lever two; The upper end of the force transmission rod is hinged to two levers, and the lower end of the force transmission rod is hinged to lever.

[0009] Preferably, a fixed suspension is provided on the lever, the lower end of the fixed suspension is rotatably connected to the outer end of the lever, and the upper end of the fixed suspension is mounted on a fixed bracket.

[0010] Preferably, the counterweight is fixed to lever two by bolts or a snap-fit ​​structure.

[0011] Preferably, the force measuring device is a tension sensor or a pressure sensor, one end of which is connected to the free end of lever two, and the other end is fixed to the bottom surface of the fixed bracket.

[0012] Preferably, the lyostat test soil box and lever one, lever two, and fixed suspension have an overlapping area in the height direction to reduce the overall height of the lyostat system.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows: (1) This utility model, through the synergy of lever two and the counterweight, significantly offsets the initial weight of the soil box in the lysimeter experiment, so that the force measuring device only needs to monitor the small weight changes caused by soil evaporation, crop transpiration and rainfall / irrigation, avoiding the impact of large loads on sensor sensitivity, realizing high-precision data acquisition, and adapting to the needs of monitoring trace moisture changes. The fixed suspension and fixed support ensure that the fulcrum and lever arm of lever one and lever two are constant, and the force transmission connecting plate and force transmission rod construct a symmetrical and lossless force transmission path, avoiding measurement errors caused by structural offset or force transmission deviation, and ensuring the long-term reliability of experimental data.

[0014] (2) The experimental soil box of the lysimeter of this utility model is embedded in the suspended tray and overlaps with lever one, lever two and fixed suspension in the height direction, which greatly reduces the overall height of the system, reduces the space occupied for installation, avoids the risk of high-altitude operation, and improves the convenience of equipment deployment and maintenance. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0016] The following are the labels in the diagram: 1. Soil box for lysimeter test; 2. Suspended tray; 3. Force transmission plate; 4. Lever 1; 5. Fixed suspension; 6. Fixed bracket; 7. Force transmission rod; 8. Lever 2; 9. Force measuring device; 10. Counterweight. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0018] Example: Please see Figure 1 An embedded high-precision weighing lysimeter based on lever balance includes a fixed bracket 6, a tray assembly movably connected to the fixed bracket 6, an lysimeter test soil box 1 set on the tray assembly, the lysimeter test soil box 1 being used to load test soil and crops, and a weighing component set below the tray assembly for detecting the weight of the lysimeter test soil box 1 loaded with test soil and crops. The pallet assembly includes a suspended pallet 2. Each of the four corners of the suspended pallet 2 is equipped with a force-transmitting connecting plate 3. Lever 4 is installed on the inner side of the upper end of each of the two opposing force-transmitting connecting plates 3. A force-transmitting tie rod 7 is installed near the lower inner end of each of the two levers 4. The upper end of the tie rod 7 is hinged to each of the two levers 4, and the lower end of the tie rod 7 is hinged to a second lever 8. The force is transmitted from lever 4 to lever 8 through the tie rod 7. The tie rod 7 acts as a force transmission bridge between lever 4 and lever 8, vertically transmitting the force from lever 4 to lever 8. The hinged connection accommodates angular changes during the rotation of the two levers, ensuring no additional resistance during force transmission and guaranteeing the accuracy of force value transmission.

[0019] The weighing assembly includes a force measuring device 9. A lever 8 is rotatably connected to one side of the force measuring device 9. The middle of the lever 8 is rotatably mounted on the bottom of a fixed support 6 via a bracket. A counterweight 10 is mounted on the other end of the lever 8, and the counterweight 10 is fixed to the lever 8 by bolts or a snap-fit ​​structure. The force measuring device 9 is a tension sensor or a pressure sensor, with one end connected to the free end of the lever 8 and the other end fixed to the bottom surface of the fixed support 6. Under the premise that the weight of the soil box 1 and the counterweight 10 in the lysimeter experiment remain constant, when soil evaporation, crop transpiration, or rainfall / irrigation cause minute changes in weight, the force on the force measuring device 9 will change synchronously. By converting the force signal into an electrical signal, accurate measurement and data output of minute weight changes are achieved.

[0020] Specifically, the suspended tray 2 carries the soil box 1 for the lysimeter test and evenly distributes the weight of the soil box to the force transmission plates 3 at the four corners, avoiding uneven local stress that could affect weighing accuracy. The suspension structure, in conjunction with subsequent lever components, provides a stable installation posture for the soil box. The two ends of the force transmission plates 3 are movably connected to the ends of lever 4 and the side walls of the suspended tray 2, respectively.

[0021] In this application, a fixed suspension 5 is provided on lever 4. The lower end of the fixed suspension 5 is rotatably connected to the outer end of lever 4, and the upper end of the fixed suspension 5 is mounted on a fixed bracket 6. The upper end of the fixed suspension 5 is fixed to the fixed bracket 6 by four sets of high-strength bolts (M12 specification). Lever 4 uses the fixed suspension 5 as a fulcrum to distribute and transmit the weight transmitted from the force transmission plate 3. Through the fixed ratio of the lever arms at both ends, the weight is converted into a stable force, which is transmitted to the force transmission rod 7 through the middle connecting seat, providing a uniform input force for the subsequent lever 8.

[0022] In this application, the lyometer test soil box 1 overlaps with lever 1 4, lever 2 8, and fixed suspension 5 in the height direction to reduce the overall height of the lyometer system.

[0023] Force transmission plate 3: The force transmission component connecting the suspended pallet 2 and lever 4, vertically transmits the weight of the soil box from the pallet to lever 4, and is symmetrically set at the four corners to ensure that the weight is evenly distributed to the two levers 4, reducing force transmission deviation.

[0024] Lever 28: The second-level core balance lever, with the central support as the fulcrum (fixed to the bottom of the fixed support 6), integrates three forces (the input force of the force transmission rod 7, the balancing force of the counterweight 10, and the monitoring force of the force measuring device 9); through a fixed lever arm ratio, the three forces satisfy the lever balance mathematical relationship.

[0025] Counterweight 10: A lever balance adjustment component, fixed to the end of lever 2 8 by bolts / clips, its weight and lever arm are constant; its function is to balance most of the initial weight of the lysimeter test soil box 1, so that the force measuring device 9 does not need to bear the weight of the entire box, but only needs to monitor the small weight fluctuations caused by changes in moisture, which greatly improves the measurement accuracy and sensitivity of the force measuring device.

[0026] In this application, the lysimeter test chamber 1 is embedded in the middle of the lever-type weighing assembly. The lysimeter test soil chamber 1 and the lever-type weighing assembly overlap in the height direction, effectively reducing the overall height of the lysimeter system. The lever-type weighing assembly uses a large counterweight 10 installed at a fixed position in the lever system to basically balance the weight of the solids in the test chamber. Then, a force measuring device 9 monitors the minute changes in the weight of water in the test soil, thereby measuring the amount of water infiltrated by crop transpiration, soil evaporation, and rainfall, irrigation, etc. in the test chamber.

[0027] Working principle: The lyostat test soil box 1 is embedded in the suspended tray 2, and the entire weight of the soil box is stably supported by the suspended tray 2, ensuring that the weight is evenly transferred to the subsequent weighing components. Lever 1 4 is connected to the fixed support 6 through the fixed suspension 5 (the lower end of the fixed suspension 5 is rotatably connected to the outer end of lever 1 4, and the upper end is fixed to the fixed support 6 with high-strength bolts), forming the stable fulcrum of lever 1; lever 2 8 uses the middle support as the fulcrum (the support is fixed to the bottom of the fixed support 6), constructing a two-stage lever balance system. The specific force transmission and balance process is as follows: Weight transfer path: The weight (denoted as G) of the soil box 1 in the lyostat test is transferred to the force transmission plates 3 at the four corners through the suspended tray 2. The force transmission plates 3 evenly distribute the vertically downward force to the two opposing levers 4. Under this downward force, lever 4 rotates slightly around its connection point with the fixed suspension 5 (i.e., the fulcrum of lever 1), causing an upward force to be generated at one end of lever 4. This force (denoted as F1, i.e., the mutual force generated between lever 1 and lever 2 through the force transmission rod 7) is vertically transferred to lever 8 through the hinged force transmission rod 7. The hinged structure of the force transmission rod 7 can adapt to the angle changes during the rotation of the two levers, avoiding additional resistance during force transmission and ensuring the accuracy of force value transmission.

[0028] Mathematical principle of lever balance: Level 1 lever balance: According to the lever balance condition "effort × effort arm = resistance × resistance arm", the balance relationship of level 1 lever is satisfied as follows: G×L1 = F1×L2 Where L1 is the vertical distance from the weight G of the box to the fulcrum of the lever (i.e., the lever arm of G), and L2 is the vertical distance from the force F1 of the force transmission rod to the fulcrum of the lever (i.e., the lever arm of F1). By designing a fixed ratio of L1 to L2 (e.g., L1:L2=1:5), the initial weight G of the large soil box can be converted into a smaller force F1, thus initially reducing the load pressure of the secondary lever.

[0029] Second-level lever (lever two) balance: Lever two simultaneously bears the torque of three forces, namely F1 transmitted by the force transmission rod (with stress arm L3, i.e., the vertical distance from F1 to the fulcrum of lever two), the gravity of the counterweight 10 (denoted as T, with stress arm L5, i.e., the vertical distance from T to the fulcrum of lever two), and the supporting force of the force measuring device 9 (denoted as F2, with stress arm L4, i.e., the vertical distance from F2 to the fulcrum of lever two).

[0030] Based on the assumption that "torques on the same side have the same direction, and torques on opposite sides have opposite directions" (F1 and T are on the same side of the fulcrum of the lever, and their torque directions are both clockwise; F2 is on opposite sides of the fulcrum, and its torque direction is counterclockwise), the equilibrium relationship of the lever is satisfied as follows: F1×L3 = F2×L4 + T×L5 High-precision weighing implementation logic: In the above mathematical formula, L1, L2, L3, L4, and L5 are all fixed lever arm parameters after equipment assembly. The weight of the counterweight T can be pre-adjusted through bolts or clips. In practical applications, by matching a suitable counterweight T, the torque value of T×L5 is made close to the torque value of F1×L3 (i.e., the counterweight can offset most of the torque after the initial weight of the soil box is transmitted through the lever). At this time, the force measuring device 9 only needs to reflect the "difference between F1×L3 and T×L5"—this difference corresponds precisely to the weight reduction caused by soil evaporation and crop transpiration, or the weight increase caused by rainfall / irrigation (i.e., the small weight fluctuation caused by changes in moisture).

[0031] Since F2 only needs to monitor minute load changes, a small-range, high-precision tension or pressure sensor (e.g., range 50-200N, accuracy 0.1N) can be selected, avoiding the problem of "large loads affecting sensor sensitivity" in traditional direct weighing equipment. Simultaneously, the rigid constraints of the fixed bracket 6 and fixed suspension 5 ensure that the fulcrum and lever arm of the two-stage lever remain constant over a long period. Combined with the symmetrical force transmission design of the force transmission connecting plate 3 and force transmission rod 7, measurement errors caused by structural offset or force transmission deviation can be effectively avoided. Ultimately, high-precision monitoring of soil box weight changes (accuracy down to the gram level) is achieved, meeting the research needs of soil-plant-atmosphere continuum water exchange processes.

[0032] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A high-precision weighing lysimeter based on lever balance and embedded installation, characterized in that: Includes a fixed support (6), on which a tray assembly is movably connected, on which an osmotherm test soil box (1) is provided, and below the tray assembly is a weighing component; The pallet assembly includes a suspended pallet (2), and force transmission connecting plates (3) are provided at the four corners of the suspended pallet (2). Lever 1 (4) is provided on the inner side of the upper end of the two force transmission connecting plates (3) that are arranged opposite to each other. Force transmission pull rod (7) is provided near the bottom of the inner end of the two levers 1 (4). The weighing assembly includes a force measuring device (9), one side of which is rotatably connected to a lever (8), the middle part of which is rotatably mounted on the bottom of a fixed bracket (6) via a bracket, and the other end of which is provided with a counterweight (10). The upper end of the force transmission rod (7) is hinged to two levers (4) respectively, and the lower end of the force transmission rod (7) is hinged to lever (8).

2. The high-precision weighing lysimeter based on lever balance embedded installation according to claim 1, characterized in that: A fixed suspension (5) is provided on the lever (4). The lower end of the fixed suspension (5) is rotatably connected to the outer end of the lever (4). The upper end of the fixed suspension (5) is installed on the fixed bracket (6).

3. The high-precision weighing lysimeter based on lever balance embedded installation according to claim 1, characterized in that: The counterweight (10) is fixed to lever two (8) by bolts or snap-fit ​​structure.

4. The high-precision weighing lysimeter based on lever balance embedded installation according to claim 1, characterized in that: The force measuring device (9) is a tension sensor or a pressure sensor, one end of which is connected to the free end of lever two (8), and the other end is fixed to the bottom surface of the fixed bracket (6).

5. The high-precision weighing lysimeter based on lever balance embedded installation according to claim 1, characterized in that: The lyometer test soil box (1) overlaps with lever one (4), lever two (8), and fixed suspension (5) in the height direction to reduce the overall height of the lyometer system.

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