Buoy liquid level transmitter calibration device and method

Abstract

The invention relates to the technical field of industrial instrument calibration, and provides a buoy liquid level transmitter calibration device and method.The buoy liquid level transmitter calibration device comprises a manual operator and further comprises a lifting table, a force measuring piece arranged on the lifting table and a dowel bar arranged on the force measuring piece, and the dowel bar is used for making contact with the lower end of a floater in a buoy liquid level transmitter; calculating a buoyancy value borne by the floater according to a buoyancy formula F = rho liquid gV, and enabling the dowel bar to upwards abut against the floater at different buoyancy values under the action of the lifting platform so as to simulate different buoyancy effects borne by the floater; the buoyancy value of the floater is accurately calculated, force is directly applied, a traditional water calibration or weight hanging mode is replaced, errors caused by environmental factors in the water calibration or weight hanging method are avoided, the method can be stably carried out in various complex industrial environments, the calibration reliability and accuracy of the float liquid level transmitter are improved, and the calibration device is easy to operate and low in cost. The device is convenient to use, calibration operation can be carried out by one person without complex cooperation, and calibration efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of industrial instrument calibration technology, specifically a calibration device and method for a float level transmitter. Background Technology

[0002] Float level transmitters are core level measurement instruments in chemical process control. They achieve high-precision continuous monitoring of liquid level by detecting changes in buoyancy on the float. In harsh chemical working conditions such as flammable and explosive, highly corrosive, high temperature and high pressure, the measurement accuracy of the instrument directly affects production safety and process stability. Therefore, calibration after installation of float level transmitters is a key step to ensure their metering performance.

[0003] Currently, industrial calibration mainly relies on the water calibration method and the weight method, but both have significant technical limitations. Specifically, for the water calibration method, this method uses water as a medium to simulate buoyancy changes, and its calibration accuracy is heavily dependent on the density stability of water. Because the density of water fluctuates significantly with temperature, changes in ambient temperature at chemical sites (such as diurnal temperature variations and seasonal changes) directly introduce systematic errors. Simultaneously, water purity (dissolved impurities, air bubble adhesion) alters the surface tension and buoyancy characteristics of the float, further interfering with calibration results. Furthermore, the operation requires repeated water filling, drainage, and level adjustments, necessitating multiple operators and is time-consuming and labor-intensive. Regarding the weight-suspension method: while this method avoids media dependence by suspending standard weights to simulate buoyancy, it requires extremely high weight precision. In actual operation, the weight suspension system is susceptible to environmental vibrations (such as pump and valve start-up and shutdown, pipeline resonance) and airflow disturbances (ventilation systems, outdoor installations), causing the weights to swing or deflect, disrupting the force balance and leading to inaccurate calibration results. Moreover, the assembly of weights and the disassembly and assembly of the float are cumbersome, resulting in low calibration efficiency.

[0004] Therefore, the present invention proposes a calibration device and method for a float level transmitter to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a calibration device and method for a float level transmitter to solve the above-mentioned problems.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A calibration device for a float level transmitter includes a handheld device for reading configuration parameters and writing data to the float level transmitter, a lifting platform, a force measuring element mounted on the lifting platform, and a force transmission rod mounted on the force measuring element. The force transmission rod is used to contact the lower end of the float in the float level transmitter, according to the buoyancy formula F=ρ 液gV calculates the buoyancy value of the float. The lifting platform causes the force transmission rod to push against the float with different buoyancy values, thus simulating the different buoyancy effects on the float. The range of the float level transmitter is calibrated under different buoyancy effects.

[0007] In one alternative: the range calibration includes zero-point calibration of the float level transmitter when the force transmission rod is in contact with the lower end of the float in the float level transmitter at zero buoyancy value, and full-scale calibration of the float level transmitter when the force transmission rod is in contact with the lower end of the float in the float level transmitter at full float buoyancy value.

[0008] In one alternative: the upper end face of the force transmission rod is a horizontal plane, and the upper end of the force transmission rod is provided with a first inner groove, in which a distance measuring probe is provided.

[0009] In one alternative: the upper end of the force transmission rod is further provided with a second inner groove, in which a camera for acquiring an image of the inside of the outer measuring cylinder in the float level transmitter and LED beads for supplementary lighting are provided.

[0010] In one alternative embodiment, the calibration device further includes an operation display panel, on which the force measurement value of the force measuring component, the distance measurement value of the distance measuring probe, and the image acquired by the camera are displayed.

[0011] In one alternative embodiment: the calibration device further includes a frame and a mounting base on the frame, the lifting platform is mounted on the mounting base, and the calibration device further includes an adjustment component for adjusting the position of the force transmission rod in a two-dimensional plane.

[0012] In one alternative embodiment: the calibration device further includes a bearing assembly for making the force transmission rod perpendicular to the horizontal plane, the bearing assembly including a first frame and a second frame rotatably mounted on the first frame, the mounting base rotatably mounted on the second frame, and the rotation plane of the mounting base being perpendicular to the rotation plane of the second frame, the mounting base also being provided with a counterweight.

[0013] In one alternative: the first frame is provided with a first positioning component for positioning the second frame, and the second frame is provided with a second positioning component for positioning the mounting base.

[0014] A method for calibrating a float level transmitter, using any one of the float level transmitter calibration devices described in the above technical solutions, includes the following steps: S1: Move the calibration device below the outer measuring cylinder and read the configuration parameters of the float level transmitter, including the medium density ρ, using the handheld device. 液 The volume V of the float and the weight m of the float; S2: Zero point calibration: The lifting platform extends and moves the force transmission rod upward until its upper end is in no force contact with the lower end of the float. In this state, the liquid level is calibrated to zero point. S3: Full-scale calibration: Based on the buoyancy formula F=ρ 液 gV calculates the full-scale buoyancy value, and by controlling the lifting platform, it pushes the force transmission rod and float to reach that buoyancy value, which is calibrated as 100% liquid level; S4: Write the calibration data into the float level transmitter using a handheld device to complete the upper and lower limit calibration of the float level transmitter.

[0015] Compared with the prior art, the beneficial effects of the embodiments of the present invention are as follows: By accurately calculating the buoyancy value of the float and directly applying force, this method replaces the traditional water calibration or weight-bearing method, avoiding errors caused by environmental factors (temperature, water quality, vibration, etc.) in the water calibration or weight-bearing method. It can be performed stably in various complex industrial environments, thereby improving the reliability and accuracy of the float level transmitter calibration. In addition, the calibration device is simple to operate and easy to use. A single person can perform the calibration operation without complicated coordination, which greatly reduces the calibration time and improves the calibration efficiency.

[0016] 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

[0017] 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. Furthermore, these drawings and textual descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concepts of this application to those skilled in the art through reference to specific embodiments.

[0018] Figure 1 This is a schematic diagram illustrating the use of an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the structure of an embodiment of the present invention.

[0020] Figure 3 This is a schematic diagram of the force transmission rod in an embodiment of the present invention.

[0021] Figure 4 This is a top view of the end of the force transmission rod in an embodiment of the present invention.

[0022] Figure 5 This is a schematic diagram illustrating the structure between the mounting base and the support assembly in the implementation of the present invention.

[0023] Figure 6 This is a top view of the mounting base and the support assembly in an embodiment of the present invention.

[0024] Figure reference numerals: 1-Float level transmitter body, 2-Handheld device, 3-Frame, 4-Mounting base, 5-Lifting platform, 6-Force measuring component, 7-Force transmission rod, 701-First rod segment, 702-Second rod segment, 703-Plug-in post, 704-Slot, 705-Elastic component, 8-Bearing assembly, 801-First frame, 802-Second frame, 803-Counterweight, 804-First positioning component, 805-Second positioning component, 9-Adjustment assembly, 10-Roller, 11-First inner groove, 12-Distance measuring probe, 13-Second inner groove, 14-LED bead, 15-Camera, 16-Operation display panel. Detailed Implementation

[0025] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0026] Please see Figures 1-3 A calibration device for a float level transmitter includes a handheld device 2 (preferably a 475 handheld device) for reading configuration parameters and writing data of the float level transmitter, a lifting platform 5 (the lifting platform 5 is prior art and can be electrically lifted by a device such as an electric telescopic rod, or manually lifted by a structure such as a lead screw, which is not limited here), a force measuring element 6 on the lifting platform 5, and a force transmission rod 7 on the force measuring element 6 (the force measuring element 6 is an electronic balance, electronic force gauge, etc. in the prior art). The force transmission rod 7 is used to contact the lower end of the float in the float level transmitter. The buoyancy value of the float is calculated according to the buoyancy formula F=ρliquidgV. The lifting platform 5 causes the force transmission rod 7 to push against the float upward with different buoyancy values, thereby simulating different buoyancy effects on the float, and calibrating the range of the float level transmitter under different buoyancy effects. The range calibration includes zero-point calibration of the float level transmitter when the force transmission rod 7 is in contact with the lower end of the float in the float level transmitter at zero buoyancy value, and full-scale calibration of the float level transmitter when the force transmission rod 7 is in contact with the lower end of the float in the float level transmitter at the full float buoyancy value (i.e. the float is completely immersed in the liquid).

[0027] It should be noted that this application applies to float level transmitters with a detachable drain valve (located at the lower end of the outer measuring cylinder). By removing the drain valve, the force transmission rod 7 can enter from the lower end of the outer measuring cylinder and contact and abut against the lower end of the float.

[0028] After the float level transmitter is installed, its drain valve is removed, and the calibration device is moved to the bottom of the outer measuring cylinder. The float level transmitter configuration parameters, including the medium density ρ, are read through the handheld device 2. 液 The volume V and weight m of the float are measured and compared with the design data, with corrections made as necessary (accurate acquisition of these parameters is fundamental to ensuring accurate calibration results). Zero-point calibration is then performed: the lifting platform 5 is raised, causing the force transmission rod 7 to move upwards until its upper end just contacts the lower end of the float (the force transmission rod 7 and the float only make contact, without generating interaction force; the pressure value measured by the force measuring element 6 does not change, theoretically only the weight of the force transmission rod 7 itself. This step ensures the accuracy of the float level transmitter in its initial state). In this state, the calibration is set to zero level. Next, full-scale calibration is performed: according to the buoyancy formula F=ρ... 液 The gV calculates the full-scale buoyancy value. By manipulating the lifting platform 5 to slightly raise it, the force transmission rod 7 and the float are pushed to reach the buoyancy value (i.e., the pressure value measured by the force measuring element 6 is the weight of the force transmission rod 7 itself + the buoyancy value). The calibration is set to 100% liquid level. The calibration data is written into the float level transmitter through the handheld device 2, thus completing the upper and lower limit calibration of the float level transmitter. By accurately calculating the buoyancy value of the float and directly applying force, it replaces the traditional water calibration or weight-bearing method, avoiding the errors caused by environmental factors (temperature, water quality, vibration, etc.) in the water calibration or weight-bearing method. It can be performed stably in various complex industrial environments, thereby improving the reliability and accuracy of the float level transmitter calibration. Moreover, this calibration device is simple to operate and easy to use. A single person can perform the calibration operation without complicated coordination, thus greatly reducing the calibration time and improving the calibration efficiency.

[0029] Furthermore, the force transmission rod 7 includes a first rod segment 701 and a second rod segment 702. The lower end of the second rod segment 702 is provided with a plug-in post 703, and the upper end of the first rod segment 701 is provided with a slot 704 adapted to the plug-in post 703. The plug-in post 703 is inserted into the slot 704, and an elastic element 705 (such as a spring or rubber column in the prior art) is provided between the bottom of the slot 704 and the plug-in post 703. By setting the elastic element 705, the force transmission rod 7 and the float are in non-rigid contact, thereby enabling more precise control of the contact force between the force transmission rod 7 and the float.

[0030] Please see Figure 1 , Figure 2 and Figure 4 In one embodiment of the present invention, the calibration device further includes a frame 3 and a mounting base 4 disposed on the frame 3, and the lifting platform 5 is disposed on the mounting base 4; The upper surface of the force transmission rod 7 is a horizontal plane, and the upper end of the force transmission rod 7 is provided with a first inner groove 11. The first inner groove 11 is provided with a ranging probe 12. Preferably, the ranging probe 12 is an infrared ranging probe. The upper end of the force transmission rod 7 is also provided with a second inner groove 13, and the second inner groove 13 is provided with a camera 15 for acquiring the image inside the outer measuring cylinder in the float level transmitter and a lamp bead 14 for supplementary lighting. The calibration device also includes an operation display panel 16, on which the force measurement value of the force measuring element 6, the distance measurement value of the distance measuring probe 12, and the image acquired by the camera 15 are displayed.

[0031] In this embodiment, since the float level transmitter is only calibrated by disassembling its drain valve, the outer measuring cylinder obstructs the float located inside, making it difficult for the force transmission rod 7 to quickly align with the float. Therefore, this embodiment sets up the above-mentioned structure to solve this problem. Specifically, the operator first moves the calibration device below the outer measuring cylinder so that the force transmission rod 7 can move upward and enter the outer measuring cylinder. Then, the lifting platform 5 raises the force transmission rod 7 to its upper end and enter the outer measuring cylinder. The camera 15 acquires an image of the inside of the outer measuring cylinder and displays it on the operation display panel 16. Based on the displayed image, the operator moves the calibration device to adjust the position of the force transmission rod 7 to align with the float. Then, the lifting platform 5 extends to drive the force transmission rod 7 upward. During this process, the distance between the upper end of the force transmission rod 7 and the lower end of the float is measured in real time by the ranging probe 12 and displayed on the control panel 16. The distance between the groove opening of the first inner groove 11 (i.e., the upper end face of the force transmission rod 7) and the zero point of the ranging probe 12 is constant (hereinafter referred to as the "contact distance"). When the ranging probe 12 measures that the distance between the upper end of the force transmission rod 7 and the lower end of the float reaches the contact distance, it means that the upper end of the force transmission rod 7 is in contact with the lower end of the float and no interaction force is generated. This is verified by whether the force measurement value of the force measuring component 6 changes (the force measurement value of the force measuring component 6 should not change).

[0032] Furthermore, in this embodiment, the bottom of the frame 3 is symmetrically provided with several sets of rollers 10 to facilitate the movement of the calibration device, and the rollers 10 are self-locking rollers.

[0033] Furthermore, in this embodiment, the calibration device further includes an adjustment component 9 for adjusting the position of the force transmission rod 7 in a two-dimensional plane (i.e., in the X and Y directions). The mounting base 4 is disposed on the adjustment component 9. The adjustment component 9 includes driving components (such as servo motors, stepper motors, linear motors, etc.), transmission and guiding components (such as ball screws and nut pairs, linear guides and sliders, synchronous belts and pulleys, etc.), structural support and connection components, auxiliary control and feedback components, etc. The connection and cooperation between the above components are existing technologies and will not be described in detail here. Combined with the external measurement obtained by the camera 15, The image inside the measuring cylinder is used to adjust the position of the force transmission rod 7 in a two-dimensional plane to align it with the float, without moving the calibration device, making the operation more convenient and faster. Alternatively, it can be based on image recognition technology combined with the adjustment component 9. The camera 15 acquires and analyzes the image inside the measuring cylinder, and then controls the adjustment component 9 to automatically perform the corresponding actions to adjust the position of the force transmission rod 7 to quickly align it with the float. The above-mentioned image recognition and automatic control technology is existing technology, and the software and hardware required to achieve the above technical effects, as well as the corresponding connections and logical relationships, will not be described in detail here.

[0034] Please see Figure 1 , Figure 5 and Figure 6 In one embodiment of the present invention, the calibration device further includes a bearing assembly 8 for making the force transmission rod 7 perpendicular to the horizontal plane. The bearing assembly 8 includes a first frame 801 and a second frame 802 rotatably disposed on the first frame 801. The mounting base 4 is rotatably disposed on the second frame 802, and the rotation plane of the mounting base 4 is perpendicular to the rotation plane of the second frame 802. The mounting base 4 is also provided with a counterweight 803. The first frame 801 is provided with a first positioning component 804 for positioning the second frame 802, and the second frame 802 is provided with a second positioning component 805 for positioning the mounting base 4. The first positioning component 804 and the second positioning component 805 can be telescopic devices such as electric telescopic rods or telescopic cylinders with abutment blocks at their movable ends. Positioning is achieved by the telescopic device extending and causing the abutment blocks to press against the second frame 802 / mounting base 4. Alternatively, it can be a locking structure (with claws), a brake locking structure, or other structures in the prior art. This embodiment does not limit the specific implementation.

[0035] In this embodiment, the calibration device requires ensuring the parallelism between the force transmission rod 7 and the float (i.e., the central axis of the force transmission rod 7 and the central axis of the float should be kept as parallel as possible) to achieve accurate calibration. The float level transmitter is installed vertically (i.e., the axis of the float is parallel to the direction of gravity). Therefore, in this embodiment, it is sufficient to ensure that the axis of the force transmission rod 7 is parallel to the direction of gravity. The calibration device is moved to the bottom of the outer measuring cylinder. Under the gravity of the counterweight 803, the second frame 802 and the mounting base 4 undergo adaptive deflection, thereby making the axis of the force transmission rod 7 parallel to the direction of gravity. Then, the first positioning component 804 and the second positioning component 805 respectively position the second frame 802 and the mounting base 4, so that the force transmission rod 7 remains in its current state. Then, the subsequent alignment, contact, and abutment between the force transmission rod 7 and the float are performed to simulate buoyancy.

[0036] The present invention also provides a calibration method for a float level transmitter, which adopts the float level transmitter calibration device described in any of the above technical solutions, and includes the following steps: S1: Move the calibration device below the outer measuring cylinder and read the configuration parameters of the float level transmitter, including the medium density ρ, using the handheld device 2. 液 The volume V and weight m of the float are recorded and compared with the design data, and corrections are made as necessary. S2: Zero point calibration: The lifting platform 5 extends and drives the force transmission rod 7 to move upward until its upper end is in no force contact with the lower end of the float. In this state, the liquid level is calibrated to zero point. S3: Full-scale calibration: Based on the buoyancy formula F=ρ 液 gV calculates the full-scale buoyancy value, and by controlling the lifting platform 5, it pushes the force transmission rod 7 and the float to reach the buoyancy value, which is calibrated as 100% liquid level; S4: Write the calibration data into the float level transmitter using the handheld device 2 to complete the upper and lower limit calibration of the float level transmitter.

[0037] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A calibration device for a float level transmitter, comprising a handheld device (2) for reading configuration parameters of the float level transmitter and writing data, characterized in that, It also includes a lifting platform (5), a force measuring element (6) mounted on the lifting platform (5), and a force transmission rod (7) mounted on the force measuring element (6). The force transmission rod (7) is used to contact the lower end of the float in the float level transmitter. According to the buoyancy formula F=ρ 液 gV calculates the buoyancy value of the float, and through the action of the lifting platform (5), the force transmission rod (7) is made to push against the float with different buoyancy values ​​to simulate the different buoyancy effects on the float, and the range of the float level transmitter is calibrated under different buoyancy effects.

2. The calibrating device for a float level transmitter according to claim 1, characterized in that, The range calibration includes zero-point calibration of the float level transmitter when the force transmission rod (7) contacts the lower end of the float in the float level transmitter at zero buoyancy value, and full-range calibration of the float level transmitter when the force transmission rod (7) contacts the lower end of the float in the float level transmitter at full float buoyancy value.

3. The calibrating device for a float level transmitter according to claim 1, characterized in that, The upper surface of the force transmission rod (7) is horizontal, and the upper end of the force transmission rod (7) is provided with a first inner groove (11), and a distance measuring probe (12) is provided in the first inner groove (11).

4. The calibrating device for a float level transmitter according to claim 3, characterized in that, The upper end of the force transmission rod (7) is also provided with a second inner groove (13), and the second inner groove (13) is provided with a camera (15) for acquiring the image inside the outer measuring cylinder of the float level transmitter and a lamp bead (14) for supplementary lighting.

5. The calibrating device for a float level transmitter according to claim 4, characterized in that, The calibration device also includes an operation display panel (16), on which the force measurement value of the force measuring component (6), the distance measurement value of the distance measuring probe (12), and the image acquired by the camera (15) are displayed.

6. The calibrating device for a float level transmitter according to claim 4, characterized in that, The calibration device also includes a frame (3) and a mounting base (4) on the frame (3). The lifting platform (5) is located on the mounting base (4). The calibration device also includes an adjustment component (9) for adjusting the position of the force transmission rod (7) in a two-dimensional plane.

7. The calibrating device for a float level transmitter according to claim 6, characterized in that, The calibration device further includes a bearing assembly (8) for making the force transmission rod (7) perpendicular to the horizontal plane. The bearing assembly (8) includes a first frame (801) and a second frame (802) rotatably mounted on the first frame (801). The mounting base (4) is rotatably mounted on the second frame (802), and the rotation plane of the mounting base (4) is perpendicular to the rotation plane of the second frame (802). The mounting base (4) is also provided with a counterweight (803).

8. The calibrating device for a float level transmitter according to claim 7, characterized in that, The first frame (801) is provided with a first positioning component (804) for positioning the second frame (802), and the second frame (802) is provided with a second positioning component (805) for positioning the mounting base (4).

9. A method for calibrating a float level transmitter, using the float level transmitter calibration device according to any one of claims 1-8, characterized in that, Includes the following steps: S1: Move the calibration device to the bottom of the outer measuring cylinder and read the configuration parameters of the float level transmitter, including the medium density ρ, through the handheld device (2). 液 The volume V of the float and the weight m of the float; S2: Zero point calibration: The force transmission rod (7) is moved up by the extension of the lifting platform (5) until its upper end is in contact with the lower end of the float without any force. In this state, the zero point liquid level is calibrated. S3: Full-scale calibration: Based on the buoyancy formula F=ρ 液 gV calculates the full-scale buoyancy value, and by controlling the lifting platform (5) to push the force transmission rod (7) to reach the buoyancy value with the float, it is calibrated as 100% liquid level; S4: Write the calibration data into the float level transmitter using the handheld device (2) to complete the upper and lower limit calibration of the float level transmitter.

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