Electromagnetic flowmeter

Abstract

To enable diagnostic operations of an electromagnetic flowmeter at site to be uniformly and easily performed.SOLUTION: A storage unit 131 stores description information for a connection between a measurement circuit 104 and a location of measurement for each of a plurality of locations of measurement (jumper terminals 105a, 105b, 105c, 105d) in measurement. An acquisition function unit 134 acquires, upon switching to an inspection mode, the description information describing the connection between the measurement circuit 104 and the location of measurement for each of the plurality of locations of measurement from the storage unit 131. A presentation function unit 135 presents the description information acquired by the acquisition function unit 134.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electromagnetic flowmeter. [Background technology]

[0002] When measuring flow rates using an electromagnetic flowmeter, leakage of the coil current that determines the magnitude of the magnetic field or of the electromotive force generated between the electrodes makes it impossible to measure flow rates accurately. For this reason, it is important to diagnose electromagnetic flowmeters by actually measuring the insulation resistance of paths where leakage may occur, such as between the coil and ground and between the electrodes and ground (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-106879 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional insulation resistance testing using actual measurements like those described above, an insulation resistance tester is prepared and carried to the site, and the test is performed by connecting the insulation resistance tester to the equipment to be diagnosed. However, this type of on-site work requires the management and transfer of procedures and know-how, such as how to connect the insulation resistance tester to the equipment, which makes on-site work difficult and prone to variation.

[0005] The present invention has been made to solve the above problems, and has as its object to make it possible to uniformly and easily carry out on-site diagnostic work on electromagnetic flow meters. [Means for solving the problem]

[0006] an excitation coil that applies a magnetic field in a direction perpendicular to the flow direction of the fluid to be measured; electrodes that are provided at each location facing the direction perpendicular to the applied magnetic field and extract the electromotive force generated in the fluid by the applied magnetic field; a measurement unit configured to calculate the flow rate based on the electromotive force; a measurement circuit that measures the resistance between the excitation coil and an earth electrode and the resistance between the electrode and the earth electrode; jumper terminals or switches for connecting the measurement circuit to the measurement locations; and a diagnostic control unit.The diagnostic control unit has a memory unit that stores explanatory information about the connection between the measurement circuit and the measurement locations for each of a plurality of measurement locations based on predetermined test contents; a reception function unit that receives an instruction to switch between measurement mode and test mode; a switching function unit that switches between the measurement mode and test mode when the reception function unit receives the instruction; an acquisition function unit that, when switched to the test mode, acquires explanatory information about the connection between the measurement circuit and the measurement locations from the memory unit for each of the plurality of measurement locations; a presentation function unit that presents the explanatory information acquired by the acquisition function unit; and a writing function unit that writes the measurement results to the memory unit when a resistance measurement is performed by the measurement circuit.

[0007] In one configuration example of the electromagnetic flowmeter, the presentation function unit presents explanatory information for each of a plurality of measurement points.

[0008] In one configuration example of the electromagnetic flowmeter, the presentation function unit presents the results of the resistance measurement performed by the measurement circuit in addition to the explanatory information.

[0009] In one configuration example of the electromagnetic flowmeter, the presentation function unit presents explanatory information and implementation results for each of a plurality of measurement locations.

[0010] In one example configuration of the above-mentioned electromagnetic flowmeter, a display unit is arranged on an operation panel on the front of the main body, a jumper terminal or switch is arranged on the operation panel together with the display unit, and a presentation function unit displays the subject of presentation on the display unit. [Effects of the Invention]

[0011] As described above, according to the present invention, a measurement circuit is provided that measures the resistance between the excitation coil and the earth electrode, and the resistance between the electrode and the earth electrode, and explanatory information about the connection between the measurement circuit and each of the multiple measurement points in the measurement is presented, so that on-site diagnostic work on electromagnetic flowmeters can be carried out uniformly and easily. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing the configuration of an electromagnetic flowmeter according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing a partial configuration of an electromagnetic flowmeter according to an embodiment of the present invention. [Figure 3] FIG. 3 is a configuration diagram showing a partial configuration of another electromagnetic flowmeter according to an embodiment of the present invention. [Figure 4] FIG. 4 is a configuration diagram showing a partial hardware configuration of another electromagnetic flow meter according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] An electromagnetic flowmeter according to an embodiment of the present invention will be described below with reference to Fig. 1. This electromagnetic flowmeter includes an exciting coil 101, electrodes 102, a measuring unit 103, a measuring circuit 104, jumper terminals 105a, 105b, 105c, 105d, and 105e, a diagnostic control unit 106, a display unit 111, and an input unit 112. This electromagnetic flowmeter also includes a measurement control unit 108. The measuring unit 103, the measuring circuit 104, the diagnostic control unit 106, and the measurement control unit 108 are housed in a converter 120.

[0014] The excitation coil 101 applies a magnetic field in a direction perpendicular to the flow direction of the fluid flowing through the measuring tube 150. Under the control of the excitation circuit 107 of the measurement control unit 108, a square wave current of a set frequency is applied from the excitation circuit 107 to the excitation coil 101, thereby generating a magnetic field.

[0015] The electrodes 102 are provided at locations facing each other in a direction perpendicular to the magnetic field applied from the excitation coil 101, and extract the electromotive force generated in the fluid by the applied magnetic field. The measurement unit 103 outputs the extracted electromotive force to the calculation unit 110 of the measurement control unit 108. For example, the electromotive force is output based on the potential of the earth electrode 102a, which is provided in contact with the fluid flowing through the measuring tube 150. The measurement unit 103 includes, for example, an amplifier circuit 103a and an A / D conversion circuit 103b. The extracted electromotive force is amplified by the amplifier circuit 103a and converted into a digital signal by the A / D conversion circuit 103b. The calculation unit 110 calculates the flow rate value based on the converted digital signal.

[0016] The measuring circuit 104 measures the resistance between the exciting coil 101 and the earth electrode 102, and the resistance between the electrode 102 and the earth electrode 102. Jumper terminals 105a, 105b, 105c, 105d, and 105e are terminals that an operator uses to connect the measuring circuit 104 to the measurement point on-site when offline. When online, the jumper terminals 105a, 105b, 105c, 105d, and 105e are disconnected from the measuring unit 103. The measuring circuit 104 measures the resistance between the earth and the measurement target connected to the jumper terminal 105e.

[0017] For example, by connecting jumper terminal 105a and jumper terminal 105e, measurement circuit 104 can measure the resistance between one terminal of excitation coil 101 and the ground. Also, by connecting jumper terminal 105b and jumper terminal 105e, measurement circuit 104 can measure the resistance between the other terminal of excitation coil 101 and the ground.

[0018] Furthermore, by connecting jumper terminal 105c and jumper terminal 105e, measurement circuit 104 can measure the resistance between one electrode 102 and ground. Furthermore, by connecting jumper terminal 105d and jumper terminal 105e, measurement circuit 104 can measure the resistance between the other electrode 102 and ground. Furthermore, jumper terminals can be provided for measuring the ground resistance of the shield wire used to suppress noise in the connecting wire of electrode 102. Using these jumper terminals, the ground resistance of the shield wire of one electrode 102 and the ground resistance of the shield wire of the other electrode 102 can be measured.

[0019] For example, as shown in FIG. 2, this electromagnetic flowmeter has a display unit 111 arranged on an operation panel 121 on the front of the converter 120 (main body), and jumper terminals 105a, 105b, 105c, 105d, and 105e are arranged on the operation panel 121 together with the display unit 111.

[0020] For example, an identification symbol "X" is engraved near jumper terminal 105a for connection to excitation coil 101, an identification symbol "Y" is engraved near jumper terminal 105b for connection to excitation coil 101, an identification symbol "A" is engraved near jumper terminal 105c for connection to electrode 102, and an identification symbol "B" is engraved near jumper terminal 105d for connection to electrode 102. An identification symbol "M" is engraved near jumper terminal 105e of measuring circuit 104. Operation panel 121 may be provided with a mode switching button 122, a cursor button 123, and the like as input unit 112. Display unit 111 may be configured as a touch panel, allowing it to be used as input unit 112.

[0021] The diagnosis control unit 106 includes a storage unit 131 , a reception function unit 132 , a switching function unit 133 , an acquisition function unit 134 , a presentation function unit 135 , and a writing function unit 136 .

[0022] The storage unit 131 stores explanatory information about the connection between the measurement circuit 104 and each of a plurality of measurement points (jumper terminals 105a, 105b, 105c, and 105d) based on predetermined test contents. For example, explanatory information such as "Test 1: Connect terminal M to terminal X," "Test 2: Connect terminal M to terminal Y," "Test 3: Connect terminal M to terminal A," and "Test 4: Connect terminal M to terminal B" is stored in the storage unit 131.

[0023] The reception function unit 132 receives an instruction to switch between the measurement mode and the inspection mode. For example, a switching instruction input by an operator operating the input unit 112 is received by the reception function unit 132. When the reception function unit 132 receives the instruction, the switching function unit 133 switches between the measurement mode and the inspection mode.

[0024] When switching to the inspection mode, the acquisition function unit 134 acquires explanatory information explaining the connection between the measurement circuit 104 and the measurement points from the storage unit 131 for each of the multiple measurement points. The presentation function unit 135 presents the explanatory information acquired by the acquisition function unit 134. When the measurement circuit 104 measures the resistance, the writing function unit 136 writes the measurement results to the storage unit 131. The measurement results written to the storage unit 131 can be read by a higher-level device in the control system to which the electromagnetic flowmeter is connected via communication using a field bus or the like, and can be shared throughout the system.

[0025] The presentation function unit 135 can also present the results of resistance measurement performed by the measurement circuit 104 together with explanatory information. The presentation function unit 135 presents the explanatory information and the results for each of a plurality of measurement locations. The presentation function unit 135 displays the presentation target on the display unit 111.

[0026] For example, when the reception function unit 132 receives a switching instruction through an operation input by an operator using the mode switching button 122, thereby switching to the test mode, the acquisition function unit 134 retrieves "Test1: Connect terminal M to terminal X" from the storage unit 131. Next, the presentation function unit 135 displays the retrieved "Test1: Connect terminal M to terminal X" on the display unit 111. By visually checking this display, the operator connects the jumper terminal 105a and the jumper terminal 105e with the jumper wire 151 and measures the resistance of one of the wires of the excitation coil 101. After this measurement is performed, the writing function unit 136 writes the measurement result into the storage unit 131. Furthermore, the presentation function unit 135 displays the measurement result on the display unit 111.

[0027] When the presentation function unit 135 presents the results of the measurement using the jumper terminal 105a, the acquisition function unit 134 retrieves the description of the next measurement point, "Test2: Connect terminal M to terminal Y," from the storage unit 131. The presentation function unit 135 displays the retrieved "Test2: Connect terminal M to terminal Y" on the display unit 111. By visually recognizing this display, the worker connects the jumper terminal 105b and the jumper terminal 105e with the jumper wire 151 and measures the resistance of the other wiring of the excitation coil 101. For example, after connecting the terminals with the jumper wire 151, the worker operates the cursor button 123 to perform the measurement of Test2. After this measurement is performed, the writing function unit 136 writes the measurement results in the storage unit 131. The presentation function unit 135 also displays the measurement results on the display unit 111.

[0028] When the presentation function unit 135 presents the results of the measurement using the jumper terminal 105b, the acquisition function unit 134 retrieves the description of the next measurement point, "Test3: Connect terminal M to terminal A," from the storage unit 131. The presentation function unit 135 outputs and displays the retrieved "Test3: Connect terminal M to terminal A" on the display unit 111. By visually checking this display, the worker connects the jumper terminal 105c and the jumper terminal 105e with the jumper wire 151 and measures the resistance of the wiring of one of the electrodes 102. After this measurement is performed, the writing function unit 136 writes the measurement results in the storage unit 131. The presentation function unit 135 also displays the measurement results on the display unit 111.

[0029] When the presentation function unit 135 presents the results of the measurement using the jumper terminal 105c, the acquisition function unit 134 retrieves the description of the next measurement point, "Test4: Connect terminal M to terminal B," from the storage unit 131. The presentation function unit 135 outputs and displays the retrieved "Test4: Connect terminal M to terminal B" on the display unit 111. By visually checking this display, the worker connects jumper terminal 105d and jumper terminal 105e with a jumper wire 151 and measures the resistance of the wiring of the other electrode 102. After this measurement is performed, the writing function unit 136 writes the measurement results in the storage unit 131. The presentation function unit 135 also displays the measurement results on the display unit 111.

[0030] In the above description, when the measurement result is displayed, the display for the next measurement is automatically made, but this is not limited to this. For example, an instruction acceptance button for accepting an instruction to proceed to the next measurement can be provided along with the display of the measurement result. By operating the button for accepting the instruction to proceed, an explanation for the next measurement can be displayed. Furthermore, in the test mode, the fact that the mode is the test mode can be displayed on the display unit 111 together with an explanation.

[0031] Furthermore, the presentation function unit 135 can display a mode switching button for switching between measurement mode and inspection mode on the touch panel display unit 111, along with the display of the explanation. Measurement is performed by operating the button that accepts an instruction to switch modes. Furthermore, the above-mentioned instruction acceptance button can be displayed on the touch panel display unit 111.

[0032] In the above description, the jumper wire 151 is used to connect any of the jumper terminals 105a, 105b, 105c, and 105d to the jumper terminal 105e and to switch the connection between them. However, as shown in FIG. 3, the switch 152 can be used to connect and switch the connection between these terminals.

[0033] 4, the above-mentioned diagnosis control unit 106 can be a computer device including a CPU (Central Processing Unit) 301, a main memory device 302, an external memory device 303, a network connection device 304, etc., and the CPU 301 can operate (execute) a program loaded in the main memory device 302 to realize the functions of the above-mentioned memory unit 131, reception function unit 132, switching function unit 133, acquisition function unit 134, presentation function unit 135, and writing function unit 136. The network connection device 304 is connected to a network 305. Furthermore, the functions can be distributed among multiple computer devices.

[0034] As described above, according to the present invention, a measurement circuit is provided that measures the resistance between the excitation coil and the earth electrode, and the resistance between the electrode and the earth electrode, and explanatory information about the connection between the measurement circuit and each of a plurality of measurement points based on predetermined test content is presented, so that on-site diagnostic work on electromagnetic flowmeters can be carried out uniformly and easily.

[0035] It should be noted that the present invention is not limited to the embodiments described above, and it is clear that many modifications and combinations can be made by a person having ordinary knowledge in the art within the technical concept of the present invention. [Explanation of symbols]

[0036] 101... excitation coil, 102... electrode, 102a... earth electrode, 103... measurement unit, 103a... amplifier circuit, 103b... A / D conversion circuit, 104... measurement circuit, 105a, 105b, 105c, 105d, 105e... jumper terminals, 107... excitation circuit, 108... measurement control unit, 110... calculation unit, 111... display unit, 112... input unit, 120... converter, 121... operation panel, 131... memory unit, 132... reception function unit, 133... switching function unit, 134... acquisition function unit, 135... presentation function unit, 136... writing function unit, 150... measurement tube.

Claims

1. an excitation coil that applies a magnetic field in a direction perpendicular to the flow direction of the fluid to be measured; electrodes provided at locations facing each other in a direction perpendicular to the applied magnetic field, for extracting electromotive force generated in the fluid by the applied magnetic field; a measuring unit configured to calculate a flow rate based on the electromotive force; a measuring circuit for measuring the resistance between the excitation coil and a ground electrode, and the resistance between the excitation coil and a ground electrode; a jumper terminal or switch for connecting the measurement circuit to the measurement point; A diagnostic control unit Equipped with The diagnosis control unit a storage unit storing explanatory information on the connection between the measurement circuit and each of a plurality of measurement points based on predetermined test contents; a reception function unit that receives an instruction to switch between a measurement mode and an inspection mode; a switching function unit that switches between a measurement mode and an inspection mode when the reception function unit receives an instruction; an acquisition function unit that, when switched to the inspection mode, acquires from the storage unit explanatory information that explains the connection between the measurement circuit and the measurement points for each of the plurality of measurement points; a presentation function unit that presents the explanatory information acquired by the acquisition function unit, and a writing function unit that writes a measurement result into the storage unit when the resistance is measured by the measurement circuit; An electromagnetic flow meter having a

2. 2. The electromagnetic flowmeter according to claim 1, The presentation function unit presents the explanatory information for each of a plurality of measurement points.

3. 2. The electromagnetic flowmeter according to claim 1, The presentation function unit presents, in addition to the explanatory information, the results of the resistance measurement performed by the measurement circuit.

4. 4. The electromagnetic flowmeter according to claim 3, The presentation function unit presents the explanatory information and the implementation results for each of a plurality of measurement points.

5. The electromagnetic flowmeter according to any one of claims 1 to 4, It has a display located on the operation panel on the front of the main unit, the jumper terminal or the switch is disposed on the operation panel together with the display unit, The presentation function unit is an electromagnetic flowmeter that displays a presentation target on the display unit.

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