Automatic calibration system of electromagnetic flowmeter

Abstract

The utility model discloses an automatic calibration system for an electromagnetic flowmeter, which comprises an upper water tank, a lower water tank, an upper computer, an electromagnetic flowmeter, a beaker, an electronic scale, an emptying pump, a circulating pump and a valve, the valve and the electromagnetic flowmeter are arranged on a pipeline connected between the upper water tank and the beaker, the beaker is placed on the electronic scale, the beaker is further connected with the lower water tank through a pipeline, the lower water tank is located at the lowest position of the system, and the electromagnetic flowmeter is arranged on the pipeline. A fluid controller is arranged on a pipeline connected between the beaker and the lower water tank, and the electromagnetic flowmeter, the electronic scale, the fluid controller, the circulating pump and the valve are all connected with the upper computer. Manual calibration is replaced, and the product precision and the production efficiency are improved.

Description

Technical Field

[0001] The utility model relates to an electromagnetic flowmeter, in particular to an automatic calibration system for an electromagnetic flowmeter. Background Art

[0002] Electromagnetic flowmeter is a liquid flow measurement device based on electromagnetic induction phenomenon. Compared with flowmeters based on other principles such as differential pressure flowmeter, it has the advantages of high precision, high reliability, and little influence by the physical properties of the liquid to be measured.

[0003] According to Faraday's law of electromagnetic induction, E = nΔΦ / Δt (n is the number of turns in the coil), the magnitude of the induced electromotive force in a circuit is proportional to the rate of change of the magnetic flux passing through it. Specifically, when a conductor cuts through magnetic lines of flux, E = BLv, and the magnitude of the induced electromotive force is solely related to the magnetic field strength B, the effective length L of the conductor, and the velocity v of the conductor cutting through the magnetic field. The magnetic field strength B and the effective length L of the conductor can be controlled through circuits and structures, and by measuring the induced electromotive force, the flow rate of the liquid can be measured.

[0004] In actual production, it is difficult to ensure the exact consistency of coil turns and electrode quality. To improve the accuracy of flow meters, each flow meter must be calibrated. Currently, calibration is generally done manually, which is prone to errors and time-consuming. Utility Model Content

[0005] In view of the defects of the existing technology, the present invention provides an automatic calibration system for an electromagnetic flowmeter.

[0006] An electromagnetic flowmeter automatic calibration system includes an upper water tank, a lower water tank, a host computer, an electromagnetic flowmeter, a beaker, an electronic scale, an emptying pump, a circulation pump, and a valve, wherein the upper water tank is located at the highest point of the system, the upper water tank is connected to the beaker via a pipeline, the valve and the electromagnetic flowmeter are provided on the pipeline connecting the upper water tank and the beaker, the beaker is placed on the electronic scale, the beaker is also connected to the lower water tank via a pipeline, the lower water tank is located at the lowest point of the system, a fluid controller is provided on the pipeline connecting the beaker and the lower water tank, and the electromagnetic flowmeter, electronic scale, fluid controller, circulation pump, and valve are all connected to the host computer.

[0007] Optionally, the fluid controller can control whether the liquid in the beaker can enter the lower water tank; the fluid controller is a solenoid valve or an emptying pump; the liquid in the upper water tank can flow into the beaker through the valve and the electromagnetic flowmeter under the action of gravity; the liquid in the lower water tank will be drawn into the upper water tank through the circulation pump; the electromagnetic flowmeter sends the measured flow value to the host computer; the electronic scale sends the measured liquid weight to the host computer; the host computer adjusts the calibration parameters of the electromagnetic flowmeter according to the deviation between the flow value and the liquid weight; the operation of the valve, fluid controller and circulation pump is controlled by the host computer; the electromagnetic flowmeter includes a magnetic circuit system, a conduit and a signal processor, the magnetic circuit system includes two oppositely arranged N and S magnetic poles, the conduit passes through the middle of the N and S magnetic poles, and electrodes are installed on the wall of the conduit, and the electrodes are connected to the signal processor.

[0008] The beneficial effect of the present invention is that it provides an automatic calibration system for an electromagnetic flowmeter, which is used to automatically complete the precision calibration of the electromagnetic flowmeter, replacing manual calibration, thereby improving product precision and production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 Schematic diagram of the structure of the electromagnetic flowmeter;

[0010] Figure 2 It is a structural diagram of the automatic calibration system;

[0011] Figure 3 is a flow chart of the calibration process. DETAILED DESCRIPTION

[0012] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, the following detailed description of specific embodiments of the present invention is provided in conjunction with the accompanying drawings, so that the above-mentioned and other objects, features, and advantages of the present invention will become more apparent. Like reference numerals denote like parts throughout the drawings. The drawings are not drawn to scale; emphasis is placed on illustrating the subject matter of the present invention.

[0013] First, a brief introduction to the electromagnetic flowmeter involved in this invention is provided. The electromagnetic flowmeter consists of a magnetic circuit system, a conduit, and a signal processor. The magnetic circuit system includes two opposing magnetic poles, N and S, with a conduit passing between them. Electrodes are mounted on the conduit wall and connected to the signal processor. The signal processor measures the output voltage of the electrodes, thereby measuring the flow rate of the fluid in the conduit.

[0014] Specifically, the N and S magnetic poles exert a constant magnetic field on both sides of the guide tube. The water flowing through the guide tube can be regarded as the movement of a conductor cutting the magnetic flux lines, and we have:

[0015] Ei=BLvi.....Formula 1

[0016] The flow rate within a sampling period is:

[0017] Vi=πr 2 tvi.....Formula 2

[0018] The total flow is:

[0019]

[0020] Where:

[0021] Ei——Induced electromotive force at both ends of the electrode

[0022] B——Magnetic field strength

[0023] L——Liquid equivalent conductor length

[0024] vi——flow rate

[0025] Vi——Flow rate within a single sampling period

[0026] V——Total flow

[0027] r——radius of the cross section of the flow guide tube

[0028] t——sampling period

[0029] n——total number of cycles

[0030] The voltage signal collected during one sampling period is used as Ei to calculate the flow rate within one sampling period. The accumulated value is continuously accumulated until the set flow rate is reached, and a pulse signal is output to the receiving device. Since the miscounting caused by using a single pulse as the metering signal has a significant impact and is inconvenient for flow rate modification during on-site use, the total number of pulses m is increased, the total flow rate is divided into m parts, and the calibration coefficient k is added to calibrate the single pulse. The flow rate corresponding to one pulse is:

[0031] Vnn=kV / m

[0032] The flow meter can be calibrated quickly by using the automatic calibration system to quickly circulate water, collect data, and calculate the k value in real time.

[0033] To automate calibration, the following automated calibration system was designed. It includes an upper water tank, lower water tank, host computer, electromagnetic flowmeter, beaker, electronic scale, drain pump, circulation pump, and valve. The upper water tank is located at the highest point of the system and is connected to the beaker via a pipeline. A valve and electromagnetic flowmeter are installed on the pipeline connecting the upper water tank and the beaker. Because the upper water tank is higher than the valve, electromagnetic flowmeter, and beaker, the liquid in the upper water tank flows into the beaker through the valve and electromagnetic flowmeter under the action of gravity.

[0034] The beaker is placed on an electronic scale, which can be used to measure the weight of the liquid in the beaker. The beaker is also connected to a lower water tank via a pipeline. The lower water tank is located at the lowest point of the system. The beaker and the lower water tank are connected by a pipeline. A fluid controller is provided on the pipeline connecting the beaker and the lower water tank. The fluid controller can control whether the liquid in the beaker can enter the lower water tank. For example, the fluid controller can be a solenoid valve. When the solenoid valve is open, the liquid in the beaker will flow into the lower water tank under the action of gravity. Conversely, when the solenoid valve is closed, the liquid in the beaker will not enter the lower water tank. The fluid controller can also be an emptying pump. When the emptying pump is turned on, the emptying pump will pump the liquid in the beaker into the lower water tank through the pipeline.

[0035] The upper water tank and the lower water tank are connected by a pipeline. A circulation pump is provided on the pipeline connecting the upper water tank and the lower water tank. When the circulation pump is turned on, the circulation pump will pump the liquid in the lower water tank into the upper water tank, thereby ensuring that the liquid in the upper water tank is not lower than the set liquid level, ensuring the calibration cycle.

[0036] The electromagnetic flowmeter, electronic scale, fluid controller, circulation pump, and valves are all connected to the host computer. The electromagnetic flowmeter transmits the measured flow rate to the host computer, while the electronic scale transmits the measured liquid weight to the host computer. The host computer then determines whether to adjust the calibration parameter K based on the deviation between the flow rate and the liquid weight. Through multiple calibrations, the flow rate measured by the flowmeter is equal to the actual flow rate measured in the beaker, thus completing the calibration of the electromagnetic flowmeter. The host computer also controls the operation of the valves, fluid controller, and circulation pump during the calibration process.

[0037] The following combination Figure 3 The specific calibration process is described. During calibration, the host computer controls the valve of the upper water tank to open, allowing water in the upper water tank to flow through the flowmeter into a beaker. The flowmeter measures the flow. When the set flow rate is reached, it sends a command to the host computer to close the valve. After the water in the beaker stabilizes, the electronic scale transmits the liquid weight data to the host computer. The host computer compares the actual weight with the flow meter's measured flow rate in real time to determine whether calibration is required. If calibration is required, it calculates the calibration parameter K and sends it back to the flowmeter. After completion, the water in the beaker is pumped into the lower water tank by the drain pump for storage. The water in the lower water tank is continuously pumped into the upper water tank by the circulation pump, completing one cycle. The host computer then determines whether another cycle is required. Generally, if the actual flow rate and the flow meter's measured flow rate are equal after five cycles, the accuracy is considered acceptable. Because the flow rate of a single pulse is significantly affected by the water flow rate, the water flow rate should be kept as stable as possible in actual use. The upper water tank of the calibration system is designed with an adjustable height inlet pipe. By adjusting the height of the pipe, the flow rate can be adjusted or fixed.

[0038] The above system realizes the automatic calibration of the electromagnetic flowmeter, improves production efficiency and reduces errors in manual operation.

[0039] In the above description, many specific details are set forth in order to fully understand the present invention. However, the above description is only a preferred embodiment of the present invention. The present invention can be implemented in many other ways different from those described herein, so the present invention is not limited by the specific implementation disclosed above. At the same time, any person skilled in the art can use the above-disclosed methods and technical contents to make many possible changes and modifications to the present invention without departing from the scope of the present invention, or modify it into an equivalent embodiment of equivalent changes. Any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the present invention is still within the scope of protection of the present invention.

Claims

1. An automatic calibration system for an electromagnetic flowmeter, characterized in that: It includes an upper water tank, a lower water tank, a host computer, an electromagnetic flowmeter, a beaker, an electronic scale, an emptying pump, a circulation pump and a valve, wherein the upper water tank is located at the highest point of the system, the upper water tank is connected to the beaker through a pipeline, the valve and the electromagnetic flowmeter are arranged on the pipeline connecting the upper water tank and the beaker, the beaker is placed on the electronic scale, the beaker is also connected to the lower water tank through a pipeline, the lower water tank is located at the lowest point of the system, a fluid controller is arranged on the pipeline connecting the beaker and the lower water tank, the electromagnetic flowmeter, electronic scale, fluid controller, circulation pump and valve are all connected to the host computer.

2. The electromagnetic flowmeter automatic calibration system according to claim 1, characterized in that: The fluid controller can control whether the liquid in the beaker can enter the lower water tank.

3. The electromagnetic flowmeter automatic calibration system according to claim 2, characterized in that: The fluid controller is a solenoid valve or an exhaust pump.

4. The electromagnetic flowmeter automatic calibration system according to claim 1, characterized in that: The liquid in the upper water tank can flow into the beaker through the valve and the electromagnetic flowmeter under the action of gravity.

5. The electromagnetic flowmeter automatic calibration system according to claim 1, characterized in that: The liquid in the lower water tank is pumped into the upper water tank by the circulation pump.

6. The electromagnetic flowmeter automatic calibration system according to claim 1, characterized in that: The electromagnetic flowmeter sends the measured flow value to the host computer.

7. The electromagnetic flowmeter automatic calibration system according to claim 6, characterized in that: The electronic scale sends the measured liquid weight to the host computer.

8. The electromagnetic flowmeter automatic calibration system according to claim 7, characterized in that: The host computer adjusts the calibration parameters of the electromagnetic flowmeter according to the deviation between the flow value and the liquid weight.

9. The electromagnetic flowmeter automatic calibration system according to claim 1, characterized in that: The operation of the valve, fluid controller and circulation pump is controlled by the host computer.

10. The electromagnetic flowmeter automatic calibration system according to claim 1, characterized in that: The electromagnetic flowmeter includes a magnetic circuit system, a conduit and a signal processor. The magnetic circuit system includes two oppositely arranged N and S magnetic poles. The conduit passes through the middle of the N and S magnetic poles. Electrodes are installed on the wall of the conduit, and the electrodes are connected to the signal processor.

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