Electromagnetic flowmeter automatic verification device

Abstract

The utility model relates to electromagnetic flowmeter detection technical field discloses a kind of electromagnetic flowmeter automatic verification device, device includes clamping unit, pneumatic synchronous clamping mechanism, fluid control module, mass flowmeter standard table, environmental parameter sensor group and automatic verification platform.One-time clamping at least 2 inspected flowmeters is supported by clamping unit, and multiple tables are synchronously clamped by linkage control through pneumatic synchronous clamping mechanism;Fluid control module uses pneumatic ball valve to control water inlet break, and electric ball valve realizes flow PID closed-loop regulation;Mass flowmeter is installed in the downstream of the table to be inspected as standard table series connection, and environmental parameter sensor group real-time monitoring fluid pressure and temperature.Automatic verification platform integrates computer and verification procedure, based on preset flow point control electric ball valve opening, standard table and the data of table to be inspected are synchronously collected, combine environmental parameter dynamic compensation fluid density variation, calculate measurement error and generate verification report, realize the synchronous verification of multiple electromagnetic flowmeters.

Description

Technical Field

[0001] This utility model relates to the field of electromagnetic flowmeter testing technology, specifically to an automatic calibration device for electromagnetic flowmeters. Background Technology

[0002] In the fields of industrial production and fluid metering, electromagnetic flowmeters are widely used in flow monitoring scenarios in industries such as chemical engineering, water conservancy, and energy due to their advantages such as wide measurement range, high accuracy, and susceptibility to the physical properties of fluids. With the continuous growth of market demand for electromagnetic flowmeters, the calibration process after mass production has become a crucial step in ensuring product quality and measurement accuracy.

[0003] Traditional electromagnetic flowmeter calibration methods often employ a single-unit, one-by-one calibration approach. Only one flowmeter can be clamped, tested, and its data recorded at a time. This process is not only cumbersome and time-consuming, but also requires frequent manual intervention to adjust equipment parameters, read data, and compile reports, resulting in low overall calibration efficiency and failing to meet the timeliness requirements of large-scale production. Furthermore, human error (such as reading deviations or parameter setting errors) during manual operation can easily affect the accuracy of calibration results, further increasing metrological risks.

[0004] In addition, traditional calibration devices have significant shortcomings in terms of fluid control and environmental adaptability.

[0005] On the one hand, its flow regulation mostly relies on manual valves, making it difficult to achieve precise and stable flow control, resulting in large flow fluctuations during the verification process and affecting the reliability of the verification data.

[0006] On the other hand, existing devices lack real-time monitoring and dynamic compensation mechanisms for environmental parameters such as fluid temperature and pressure. When the temperature and pressure in the calibration environment change, it will directly affect key parameters such as fluid density, which will lead to deviations in flow measurement results and make it impossible to guarantee calibration accuracy.

[0007] In terms of equipment and labor costs, the traditional verification model requires multiple independent verification devices to improve processing capacity, and also requires professional operators to be on duty continuously, which not only increases the cost of equipment purchase and maintenance, but also drives up the investment in labor costs.

[0008] In summary, existing electromagnetic flowmeter calibration technologies have significant shortcomings in terms of efficiency, accuracy, and cost control. There is an urgent need for a calibration solution that can achieve simultaneous calibration of multiple units, automated operation, environmental parameter compensation, and low cost to solve the calibration challenges in mass production scenarios. Utility Model Content

[0009] One objective of this invention is to address the need for efficient and low-cost calibration of electromagnetic flowmeters by providing an automatic calibration device for electromagnetic flowmeters that enables simultaneous calibration of multiple devices, significantly improving calibration efficiency and reducing costs, thus meeting the calibration requirements in mass production.

[0010] To achieve the above objectives, this utility model provides the following technical solution:

[0011] This utility model discloses an automatic calibration device for an electromagnetic flowmeter, comprising: a clamping unit, a pneumatic synchronous clamping mechanism, a fluid control module, a mass flowmeter, an environmental parameter sensor group, and an automatic calibration platform.

[0012] The clamping unit is configured to clamp at least two electromagnetic flowmeters under test at a time. A pneumatic synchronous clamping mechanism is connected to the clamping unit and controls the synchronous clamping of multiple electromagnetic flowmeters under test through a pneumatic switch. The fluid control module includes a pneumatic ball valve and an electric ball valve. The pneumatic ball valve is located at the inlet end of the fluid pipeline to control the flow of water, and the electric ball valve is used to adjust the calibration flow rate. A mass flowmeter is installed in series as a standard meter in the downstream pipeline of the electromagnetic flowmeter under test. The environmental parameter sensor group includes pressure and temperature sensors installed on the fluid pipeline for real-time monitoring of the fluid state. The automatic calibration platform includes a computer and calibration program, and is communicatively connected to the environmental parameter sensor group, the electric ball valve, the mass flowmeter standard meter, and the electromagnetic flowmeters under test.

[0013] In addition to the above-mentioned technical features, this utility model has also made optimizations and improvements in the following aspects:

[0014] As a preferred technical solution of this utility model, the clamping unit includes at least two clamping positions for positioning the electromagnetic flowmeter under test, and the structure of each clamping position is adapted to accommodate electromagnetic flowmeters of different specifications.

[0015] As a preferred technical solution of this utility model, the pneumatic synchronous clamping mechanism includes an air source, a pneumatic pressure regulating valve, a pneumatic pressure switch, and multiple clamping actuators; the air source is connected to multiple clamping actuators through pipelines, the pneumatic pressure switch is set on the pipeline to drive the clamping actuators to move synchronously through the same control signal, and the pneumatic pressure regulating valve is used to set the clamping force.

[0016] In a preferred embodiment of this utility model, in the fluid control module, the pneumatic ball valve is connected to an air source and opened and closed by air pressure; the electric ball valve is electrically connected to the automatic calibration platform and receives pulse signals or analog signals output by the automatic calibration platform to adjust the opening degree.

[0017] As a preferred technical solution of this utility model, the electric ball valve is a proportional regulating valve, and its opening degree is controlled by the automatic calibration platform according to the preset flow point through PID closed-loop control.

[0018] As a preferred embodiment of this utility model, the installation distance between the mass flow meter standard and the electromagnetic flow meter under test is less than 5 times the pipe diameter.

[0019] As a preferred embodiment of this utility model, the environmental parameter sensor group includes at least one set of pressure sensors and temperature sensors, which are installed in the pipeline between the downstream of the standard meter and the upstream of the electromagnetic flowmeter under test; the measurement data of the pressure sensors and temperature sensors are transmitted to the automatic calibration platform in real time via wired communication.

[0020] Based on the above description of the technical content, this application, through the synergistic effect of its various components, achieves a multi-dimensional technical breakthrough in addressing the shortcomings of existing technologies. The specific technical effects are reflected in the following aspects:

[0021] 1. Significantly improves testing efficiency

[0022] It supports simultaneous verification of multiple units and achieves one-time rapid clamping through a pneumatic linkage clamping mechanism, which greatly reduces clamping time.

[0023] Full-process automation: The verification program uniformly controls fluid flow, flow regulation, data acquisition and report generation, replacing manual operation, eliminating human error, significantly increasing the number of verifications per unit time, and meeting the needs of mass production.

[0024] 2. Ensure comprehensive accuracy and data reliability in verification.

[0025] High-precision benchmark: A high-precision mass flow meter is used as the standard meter, and the installation spacing is strictly controlled (less than 5 times the pipe diameter) to reduce flow interference and ensure the accuracy of standard data.

[0026] Dynamic environmental compensation: Real-time monitoring of pressure and temperature, and dynamic compensation and correction (such as mass flow rate) to eliminate the influence of fluid state changes and ensure accuracy under different operating conditions.

[0027] Steady-state data acquisition: Simultaneously acquire signals from the standard meter and the meter under test for a relatively long time (≥30 seconds) under steady-state flow conditions to avoid instantaneous fluctuations, ensure data stability and representativeness, and improve the reliability of error calculation.

[0028] 4. Effectively reduces operational complexity and overall cost.

[0029] High versatility: The clamping unit is compatible with flow meters of different specifications, eliminating the need for frequent clamp replacements, thus reducing equipment costs and operational complexity.

[0030] Automation reduces costs: Full-process automation significantly reduces the need for manual intervention, directly lowering labor costs.

[0031] Batch effect: The multi-unit synchronous verification mode effectively reduces the average energy consumption and consumable consumption of each unit of the instrument being tested, thereby achieving overall cost optimization.

[0032] 5. Enhance the controllability and standardization of the verification process.

[0033] Precise flow control: The electric proportional control valve with PID closed-loop control is used to precisely switch between different calibration flow points, ensuring that the calibration process is stable and controllable throughout the entire range and avoiding the instability of manual adjustment.

[0034] Standardized Reporting and Traceability: The system automatically generates verification reports, with data directly sourced from system data collection and calculation. This reduces errors from manual recording and provides clear data traceability, thereby improving the standardization of the verification process.

[0035] In summary, this application employs multiple synchronous clamping mechanisms, a high-precision reference and compensation mechanism, universal fixtures, closed-loop flow control, and a fully automated integrated design, which improves the efficiency of batch verification, ensures the accuracy and reliability of verification data under different working conditions, effectively reduces operational complexity, labor costs, and energy consumption per unit, and solves many problems existing in the prior art in terms of efficiency, accuracy, cost, and standardization, achieving high efficiency, high accuracy, low cost, and standardization in the batch automated verification of electromagnetic flowmeters. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the overall structure of the automatic calibration device for electromagnetic flowmeters of this utility model.

[0037] In the diagram: 1. Clamping unit; 2. Pneumatic synchronous clamping mechanism; 3. Fluid control module; 4. Mass flow meter standard table; 5. Environmental parameter sensor group; 6. Automatic calibration platform. Detailed Implementation

[0038] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0039] I. Explanation of descriptive terms used in this utility model

[0040] The embodiments provided in conjunction with the technical solutions of this utility model are intended to make the present utility model more thorough and complete, and to fully express the scope of the present utility model to those skilled in the art. It should be noted that unless otherwise specifically stated by the present utility model, the relative arrangement of components described in these embodiments should be interpreted as merely exemplary, and not as a limitation on the technical solutions of the present utility model.

[0041] In this utility model, the use of directional terms such as "upper," "lower," "left," "right," "bottom," and "top" is defined relative to the directions shown in the accompanying drawings and is used only to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly. These or other directional terms should not be construed as restrictive terms.

[0042] In this utility model, the terms "a," "an," "a kind," "the," and similar words used do not indicate quantity limitation and can represent singular or plural. The terms "comprising," "including," "having," and any variations thereof used in this utility model are intended to cover non-exclusive inclusion; the terms "first," "second," "third," etc., used in this utility model are merely to distinguish similar objects and do not represent a specific ordering of objects.

[0043] In this invention, when a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other devices without an intermediary device, or it may not be directly connected to the other devices but may have an intermediary device.

[0044] Furthermore, this utility model does not discuss in detail the technologies and equipment known to those skilled in the art, but where appropriate, such technologies and equipment should be considered part of the specification.

[0045] II. The core technical problem to be solved by the technical solution of this application

[0046] Existing electromagnetic flowmeter calibration technologies are ill-suited to the needs of mass production, with the core issues being efficiency, accuracy, and cost.

[0047] In terms of efficiency: The single-unit calibration mode can only process one test table at a time. The clamping, testing and data recording process is cumbersome and time-consuming. In addition, it requires frequent manual adjustment of parameters, reading of data and compilation of reports, resulting in low calibration efficiency and failing to meet the timeliness requirements of large-scale production.

[0048] In terms of accuracy: manual operation is prone to human error such as reading deviation and parameter setting errors, which affects the accuracy of the results; the flow regulation of the device relies on manual valves, which makes it difficult to achieve precise and stable control, resulting in large flow fluctuations during the verification. At the same time, there is a lack of real-time monitoring and dynamic compensation for environmental parameters such as fluid temperature and pressure. Environmental changes will change the fluid density, which will lead to flow measurement deviations and make it impossible to guarantee the accuracy of the verification.

[0049] In terms of cost: the traditional model requires multiple independent calibration devices to improve processing capacity, and also requires professional personnel to be on duty continuously, which increases the cost of equipment purchase and maintenance, as well as the investment in labor costs.

[0050] III. Based on the above problems, this utility model specifically provides a technical solution to solve these problems. The following describes specific embodiments and references the appendix. Figure 1 As shown, the technical solution, working principle and technical effects of this utility model are described in detail.

[0051] Example 1

[0052] In this embodiment, the automatic calibration device for electromagnetic flowmeters includes a clamping unit 1, a pneumatic synchronous clamping mechanism 2, a fluid control module 3, a mass flowmeter standard table 4, an environmental parameter sensor group 5, and an automatic calibration platform 6.

[0053] The clamping unit 1 is connected to the outlet end of the fluid control module 3 through a pipeline interface. The clamping actuators of the pneumatic synchronous clamping mechanism 2 are installed on the sides of each clamping position of the clamping unit 1. The mass flow meter standard meter 4 is connected in series in the downstream pipeline of the clamping unit 1. The environmental parameter sensor group 5 is installed on the pipeline between the downstream of the mass flow meter standard meter 4 and the upstream of the clamping unit 1. The automatic calibration platform 6 is connected to the fluid control module 3, the mass flow meter standard meter 4, the environmental parameter sensor group 5 and the electromagnetic flow meter under test through data cables.

[0054] The clamping unit 1 of the automatic calibration device for electromagnetic flowmeters is compatible with electromagnetic flowmeters of DN300-DN500 specifications, and the inner diameter of the pipe is consistent with the inner diameter of the interface of the corresponding specification of the flowmeter being tested.

[0055] The clamping unit includes six clamping positions for positioning the electromagnetic flowmeter under test. Each clamping position employs an adjustable arc-shaped chuck structure, with the chuck inner diameter adjustable from 300mm to 500mm via a manual knob to accommodate large-diameter electromagnetic flowmeters of DN300, DN400, and DN500. The clamping positions are connected by flanges, and the flange sealing surfaces use high-pressure resistant rubber gaskets to ensure zero fluid leakage.

[0056] The pneumatic synchronous clamping mechanism consists of a 0.8MPa air compressor (air source), a QTY-15 type air pressure regulating valve, a two-position five-way electromagnetic air pressure switch, and six SC63×50 cylinders (clamping actuators). The air source is connected to the six cylinders via Φ10mm PU tubing. The air pressure switch is connected in series on the main pipeline. An arc-shaped clamping block is connected to the end of the piston rod of each cylinder. The inside of the clamping block is covered with an anti-slip rubber pad. The air pressure regulating valve is set to a clamping force of 0.4MPa to avoid damaging the housing of the instrument being tested.

[0057] The fluid control module includes one DN100 pneumatic ball valve and one DN80 electric ball valve. The pneumatic ball valve is connected to an air source and achieves rapid opening and closing via air pressure, with a response time ≤0.5s. The electric ball valve is a proportional regulating valve (model: VAF51.2), electrically connected to the automatic calibration platform, and receives 4-20mA analog signals to adjust the opening degree, with an opening degree adjustment accuracy of 0.1%.

[0058] The standard mass flow meter uses a Coriolis mass flow meter with an accuracy class of 0.1 and a measuring range of 10–100 m. 3 The installation spacing between the electromagnetic flowmeter being tested and the pipe diameter is 3 times the pipe diameter (the pipe diameter is calculated based on DN500, and the spacing is 1.5m). It is fixed to the upstream and downstream pipelines through flanges.

[0059] The environmental parameter sensor group includes one MPX5100 pressure sensor (measuring range 0-10 bar, accuracy ±0.2%FS) and one PT100 temperature sensor (measuring range -20℃-100℃, accuracy ±0.1℃). The two are integrated into the same sensor module and installed at the tee interface between the downstream of the mass flow meter standard and the upstream of the electromagnetic flow meter under test. The measurement data is transmitted to the automatic calibration platform in real time via RS485 bus.

[0060] The automatic calibration platform consists of an industrial computer (configured with an Intel Core i5 processor, 8GB of memory, and a 1TB hard drive) and a customized calibration program. The computer is equipped with an RS485 communication card and an analog output card, and can simultaneously establish communication with 6 electromagnetic flow meters, mass flow meters, standard meters, electric ball valves, and environmental parameter sensor groups under test. The calibration program supports functions such as flow point setting, data acquisition, error calculation, and report generation.

[0061] The automatic calibration method for electromagnetic flowmeters in this embodiment includes the following steps:

[0062] Step 1: Connect the six electromagnetic flowmeters under test (two each of DN300, DN400, and DN500) in series and clamp them in the six clamping positions of the clamping unit. Ensure that the flange of the flowmeter under test is aligned with the flange of the pipe in the clamping unit. Activate the pneumatic pressure switch of the pneumatic synchronous clamping mechanism. The cylinder piston rod pushes the arc-shaped clamping block to move synchronously, locking the six flowmeters under test.

[0063] Step 2: Set the calibration flow point (10m) in the calibration program of the automatic calibration platform. 3 / h, 20m 3 / h, 40m 3 / h、60m 3 / h、80m 3 / h, 100m 3 / h), click the "Start Verification" button, the program outputs a control signal to the pneumatic ball valve, the pneumatic ball valve opens, and fluid enters the pipeline; at the same time, it outputs a 4-20mA analog signal to the electric ball valve, controlling the opening degree of the electric ball valve to the corresponding target flow rate (e.g., 10m). 3 / h corresponds to a 4mA signal, with an opening of 10%.

[0064] Step 3: The environmental parameter sensor group collects the pressure and temperature data of the fluid in the pipeline in real time (sampling frequency 1Hz) and transmits it to the automatic calibration platform via RS485 bus. The calibration program calculates the real-time density of the fluid based on the real-time pressure and temperature data, and corrects the temperature and pressure of the mass flow meter standard table based on the density data to achieve dynamic compensation.

[0065] Step 4: Once the flow rate stabilizes (flow rate fluctuation ≤ 0.5%), the calibration program outputs a control signal to adjust the opening of the electric ball valve, sequentially switching to each set calibration flow point. After each flow point stabilizes, the pulse signal from the mass flow meter standard and the output signal (4-20mA or pulse signal) of the electromagnetic flow meter under test are simultaneously acquired. The acquisition time is 30s, and the acquisition frequency is 10Hz.

[0066] Step 5: The calibration procedure calculates the measurement error of each meter under test at each flow point based on the collected standard data and the data under test, using the formula "Measurement error = (Measurement value of meter under test - Measurement value of standard meter) / Measurement value of standard meter × 100%".

[0067] Repeat steps two through five above to complete the full measurement range (10–100 m). 3 After verification, the verification procedure automatically calculates parameters such as the maximum error and basic error of each tested instrument, and generates a verification report in the format of JJG1033-2007 "Verification Procedure for Electromagnetic Flowmeters". It supports direct printing or export of PDF files.

[0068] Based on the above structure and working principle, this embodiment can achieve simultaneous automatic calibration of six large-diameter electromagnetic flowmeters of different specifications. Compared with the traditional single-unit calibration method, the calibration efficiency is increased by 500%, and the calibration time for a single test is reduced from the traditional 6 hours to 1.2 hours. Simultaneously, through dynamic environmental parameter compensation and PID closed-loop control of the electric ball valve, the calibration accuracy is guaranteed, with the measurement error controlled within ±0.2%, meeting the calibration requirements of 0.5-class electromagnetic flowmeters.

[0069] In addition, the standardized clamping design of the pneumatic synchronous clamping mechanism reduces operational errors from manual clamping, lowers labor costs and intensity, and achieves high efficiency and low cost in the batch calibration of large-diameter electromagnetic flowmeters.

[0070] Example 2

[0071] The difference between this embodiment and Embodiment 1 lies in the specifications of the clamping unit, the parameters of the fluid control module, and the range of the mass flow meter standard. In this embodiment, the clamping unit is adapted to small-diameter (DN15-DN50) electromagnetic flow meters under test, the valves and pipes of the fluid control module are even smaller, and the mass flow meter standard is a small-range model. The clamping unit 1 of the small flow calibration device adopts a compact layout, with the clamping distance reduced to 0.3m.

[0072] The clamping unit contains 20 clamping positions, each compatible with six small-diameter specifications: DN15, DN20, DN25, DN32, DN40, and DN50. It uses spring-loaded locating pins to achieve rapid positioning of the gauge under test. The inner diameter of the pipe at each clamping position is between 15mm and 50mm. Adjacent clamping positions are connected by reducing couplings ranging from Φ10mm to Φ50mm to ensure smooth fluid flow.

[0073] Pneumatic synchronous clamping mechanism: The air source is still a 0.8MPa air compressor, the air pressure regulating valve model is changed to QTY-8, the air pressure switch is a two-position three-way type, the clamping actuator uses 20 small cylinders of model SC32×30, the cylinder piston rod stroke is 30mm, the clamping force is set to 0.2MPa to avoid damaging the thin-walled shell of the small-diameter instrument under test, and the clamping block is made of plastic to reduce hard contact with the instrument under test.

[0074] The fluid control module uses a pneumatic ball valve (DN25) and an electric ball valve (DN20) as proportional control valves. Both valves receive 0-10V analog signals to adjust their opening, with a range of 0.1–10m. 3 / h, with an opening adjustment accuracy of 0.05%, which can meet the fine adjustment needs of small flow rates.

[0075] The standard mass flow meter uses a small-range Coriolis mass flow meter with an accuracy class of 0.05 and a range of 0.1–10 m. 3 / h, the installation distance between the electromagnetic flowmeter under test and the test is twice the pipe diameter (calculated based on DN50, the distance is 0.1m), and it is fixed to the pipe by threaded connection, reducing the installation space occupied by small diameter pipes.

[0076] Differences in operating procedures: The calibration flow point is set to 0.1m. 3 / h, 0.5m 3 / h、1m 3 / h、3m 3 / h、5m 3 / h、8m 3 / h, 10m 3 / h, a total of 7 flow points; the electric ball valve control signal was changed to a 0-10V analog signal (e.g., 0.1m). 3 / h corresponds to a 0.1V signal (1% opening); the data acquisition time remains 30s, but the sampling frequency is increased to 20Hz to ensure the accuracy of low flow rate data acquisition; in dynamic compensation, the density correction formula is optimized for low flow rate fluid characteristics to improve compensation accuracy.

[0077] Thanks to the use of small-sized clamping units and fluid control components, this embodiment can simultaneously calibrate 20 small-diameter electromagnetic flowmeters at once. Compared to the 6-unit clamping capacity of Embodiment 1, this improves batch calibration capability, with a single calibration time of only 1.5 hours. In contrast, traditional calibration of a single small-diameter electromagnetic flowmeter requires 30 minutes per unit, and 10 hours for 20 units. This embodiment significantly improves efficiency. The combination of a small-range mass flowmeter and a high-precision electric ball valve enables the calibration of small flow rates (0.1 m³ / h). 3 The measurement error of the / h) verification is controlled within ±0.15%, meeting the verification requirements of the 0.2-class small-diameter electromagnetic flowmeter. At the same time, the compact clamping layout reduces the overall footprint of the device (only 1 / 3 of that in Example 1), lowering the equipment installation space cost and making it more suitable for batch verification scenarios in laboratories or small production workshops.

[0078] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

[0079] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

Claims

1. An automatic calibration device for an electromagnetic flowmeter, characterized in that, include: The clamping unit is configured to clamp at least two electromagnetic flowmeters under test at a time. A pneumatic synchronous clamping mechanism is connected to the clamping unit and controls the synchronous clamping of multiple tested electromagnetic flowmeters through a pneumatic switch. The fluid control module includes a pneumatic ball valve and an electric ball valve. The pneumatic ball valve is located at the inlet end of the fluid pipeline to control the flow of water, and the electric ball valve is used to adjust the calibration flow rate. The mass flow meter is installed in series as a standard meter in the downstream pipeline of the electromagnetic flow meter under test. An environmental parameter sensor group, including pressure and temperature sensors installed on the fluid pipeline, is used to monitor the fluid status in real time. The automatic calibration platform includes a computer and calibration program, and is communicatively connected to the environmental parameter sensor group, electric ball valve, mass flow meter standard meter and the electromagnetic flow meter under test.

2. The automatic calibration device for electromagnetic flowmeters according to claim 1, characterized in that, The clamping unit includes at least two clamping positions for positioning the electromagnetic flowmeter under test, and the structure of each clamping position is adapted to accommodate electromagnetic flowmeters of different specifications.

3. The automatic calibration device for electromagnetic flowmeters according to claim 1, characterized in that, The pneumatic synchronous clamping mechanism includes an air source, a pressure regulating valve, a pressure switch, and multiple clamping actuators. The air source is connected to the multiple clamping actuators through pipelines. The pressure switch is installed on the pipeline to drive the clamping actuators to move synchronously through the same control signal. The pressure regulating valve is used to set the clamping force.

4. The automatic calibration device for electromagnetic flowmeters according to claim 1, characterized in that, In the fluid control module, the pneumatic ball valve is connected to an air source and is opened and closed by air pressure; the electric ball valve is electrically connected to the automatic calibration platform and receives pulse signals or analog signals output by the automatic calibration platform to adjust the opening degree.

5. The automatic calibration device for electromagnetic flowmeters according to claim 4, characterized in that, The electric ball valve is a proportional regulating valve, and its opening degree is controlled by the automatic calibration platform using PID closed-loop control based on a preset flow point.

6. The automatic calibration device for electromagnetic flowmeters according to claim 1, characterized in that, The installation distance between the standard mass flow meter and the electromagnetic flow meter under test is less than 5 times the pipe diameter.

7. The automatic calibration device for electromagnetic flowmeters according to claim 1, characterized in that, The environmental parameter sensor group includes at least one set of pressure sensors and temperature sensors, which are installed in the pipeline between the downstream of the standard meter and the upstream of the electromagnetic flowmeter under test; the measurement data of the pressure sensors and temperature sensors are transmitted to the automatic calibration platform in real time via wired communication.

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