A method and apparatus for simultaneous calibration of a flow meter

Abstract

The application discloses a simultaneous calibration method and device for flow meters, which comprises the following steps: obtaining the cumulative flow of a standard flow meter and a group of detected flow meters in a period of time; calculating the error of the detected flow meters based on the cumulative flow; calculating the corrected flow coefficient value according to the initial flow coefficient and the error; transmitting the corrected coefficient value to the detected flow meters through communication address conversion; converting the communication address by obtaining the address value corresponding to the detected flow meter and the corrected coefficient value, sending the corrected coefficient value and the default address out of the factory to the corresponding detected flow meter according to the address value, and modifying the flow coefficient of the detected flow meter according to the corrected coefficient value; and continuing the calibration until the error meets the accuracy requirement. The application avoids the problem of repeatedly modifying the address of the flow meter in the calibration process of the flow meter, and reduces the complexity of simultaneously calibrating multiple flow meters.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of flow meter calibration, and particularly relates to a simultaneous calibration method and device for flow meters. BACKGROUND

[0002] A process in the production of electromagnetic flow meters is calibration. During calibration, parameters in the flow meter need to be modified and saved. There are two methods for modifying parameters, the first is to modify through the keys on the flow meter in a manual way, and the second is to modify through 485 communication. The manual modification has the advantage of being intuitive, but is low in efficiency. In comparison, the communication modification can improve efficiency and maintain intuitive visibility. However, the communication method has a problem, that is, the devices on the 485 communication bus are distinguished according to the communication addresses of the devices. A production line needs to simultaneously calibrate multiple flow meters, and the communication addresses of each flow meter are the same when leaving the factory. Therefore, the addresses of each flow meter need to be set to be different before calibration, and then restored to the original default addresses after the calibration is completed. This brings complexity to the operation. SUMMARY

[0003] To solve the problems in the prior art and improve the calibration efficiency of flow meters, the present application adopts the following technical scheme:

[0004] A simultaneous calibration method for flow meters, comprising the following steps:

[0005] Step S1: establishing an initial state of flow meter calibration;

[0006] Step S2: obtaining the cumulative flow of a standard flow meter and a group of detected flow meters for a period of time;

[0007] Step S3: calculating the error of the detected flow meters based on the cumulative flow, and calculating the correction coefficient value according to the initial flow coefficient and the error;

[0008] Step S4: transmitting the correction coefficient value to each corresponding detected flow meter through 485 communication and address conversion, because the communication addresses of each detected flow meter are the same when leaving the factory and cannot be distinguished, a communication address conversion module is added between the flow control instrument host and the detected flow meter for automatic conversion of the communication address. The conversion of the communication address is achieved by obtaining the address value and the correction coefficient value of the detected flow meter, sending the correction coefficient value and the default address of the detected flow meter to the corresponding detected flow meter according to the address value, and modifying the flow coefficient of the detected flow meter according to the correction coefficient value;

[0009] Step S5: returning to step S2 to continue calibration until the error meets the accuracy requirement.

[0010] Further, in the step S1, the flow control instrument host controls the opening degree of the water pump and the regulating valve, so that the water flow in the straight pipe section approaches the preset target value; and waits for a suitable time for the water flow to be stable.

[0011] Further, in the step S2, the flow control instrument host starts timing, and clears the cumulative flow of the standard flowmeter and the detected flowmeter; stops timing after timing for a period of time based on the flow value size, and reads the cumulative flow of the standard flowmeter and the detected flowmeter.

[0012] Further, in the step S3, the error calculation formula is as follows:

[0013] E=(Fv-F) / F*100%

[0014] Wherein, E represents the error value, Fv represents the cumulative flow of the detected flowmeter, and F represents the cumulative flow of the standard flowmeter.

[0015] Further, in the step S3, after obtaining the error value, return to the step S2 to repeat the collection, and calculate the average error Ev based on the collection times to calculate the correction flow coefficient value K:

[0016] K=K0 / (1+Ev).

[0017] Wherein, K represents the correction flow coefficient value, and K0 represents the initial flow coefficient value.

[0018] Further, in the step S5, after the coefficient modification is completed, the steps S2 to S3 are repeatedly executed again to calculate a new average error Ev1; if the error Ev1 meets the accuracy requirement, the calibration process is ended, otherwise, the above step S4 needs to be repeatedly executed until the error reaches the accuracy requirement.

[0019] Further, the step S4 includes the following steps:

[0020] Step S4.1: encapsulate the address value corresponding to the detected flowmeter, the correction coefficient value and other necessary data in a data packet, and send the data packet to the communication address conversion module through the 485 communication line;

[0021] Step S4.2: after the communication address conversion module receives the data packet, checks the address value therein, binds the data packet with the corresponding output port according to the address value and forwards the data packet, wherein the address value needs to be modified into the factory default address of the flowmeter before forwarding, and other data remain unchanged;

[0022] Step S4.3: after the detected flowmeter receives the data packet, modifies the flow coefficient thereof according to the correction coefficient value in the data packet.

[0023] The simultaneous calibration device of the flow meter comprises a flow control instrument host, a water pump, an adjusting valve and a standard flow meter, and further comprises a communication address conversion module, the flow control instrument host controls the water pump and the adjusting valve, the cumulative flow of the standard flow meter and a group of detected flow meters is obtained within a period of time, the error of the detected flow meter is calculated based on the cumulative flow, the corrected flow coefficient value is calculated according to the initial flow coefficient and the error, the communication address conversion module obtains the address value and the corrected coefficient value corresponding to the detected flow meter, the corrected coefficient value and the default address of the factory are sent to the corresponding detected flow meter according to the address value, and the flow coefficient of the detected flow meter is modified according to the corrected coefficient value.

[0024] Further, the flow control instrument host encapsulates the address value and the corrected coefficient value corresponding to the detected flow meter and other necessary data in a data packet, and sends the data packet to the communication address conversion module through the 485 communication line; after receiving the data packet, the communication address conversion module checks the address value in the data packet, binds the data packet with the corresponding output port according to the address value, and forwards the data packet, wherein the address value in the data packet is modified into the default address of the factory of the flow meter before forwarding, and other data remain unchanged; after receiving the data packet, the detected flow meter modifies the flow coefficient according to the corrected coefficient value in the data packet.

[0025] Further, the flow control instrument host calculates the average error Ev by collecting the cumulative flow of the standard flow meter and the detected flow meter for multiple times, calculates the corrected flow coefficient value K=K0 / (1+Ev) according to the average error Ev and the initial flow coefficient value K0, and after the coefficient modification is completed, the cumulative flow is collected again to calculate the average error until the average error meets the accuracy requirement.

[0026] The advantages and beneficial effects of the present application are as follows:

[0027] The simultaneous calibration method and device of the flow meter of the present application send the corrected coefficient value and the default address of the factory to the corresponding detected flow meter according to the address value corresponding to the detected flow meter, avoid the problem that the address of the flow meter needs to be repeatedly modified during the calibration process of the flow meter, reduce the complexity of simultaneously calibrating multiple flow meters, and can be popularized in the production process of the electromagnetic flow meter and can be used in the flow meter testing institution. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a structural schematic diagram of the device in the embodiment of the present application.

[0029] Figure 2 is a flow chart of the method in the embodiment of the present application. DETAILED DESCRIPTION

[0030] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0031] like Figure 1 As shown, a simultaneous calibration device for flow meters comprises a flow controller host 1, a water pump 2, a regulating valve 3, a straight flow pipe section 4, a standard flow meter 5, multiple flow meters under test 6, and a communication address conversion module 7. The flow controller host 1 is electrically connected to the water pump 2, the regulating valve 3, the standard flow meter 5, and the flow meters under test 6. The regulating valve 3, the standard flow meter 5, and the flow meters under test 6 are sequentially fixedly mounted on the straight flow pipe section 4. The flow controller host 1 and the communication address conversion module 7 are connected via a 485 communication cable; the communication address conversion module 7 is also connected to each flow meter under test 6 via a 485 communication cable.

[0032] like Figure 2 As shown, a method for simultaneous calibration of a flow meter includes the following steps:

[0033] Step S1: The flow controller host 1 sends a command to control the opening degree of the water pump 2 and the opening degree of the regulating valve 3, so that the water flow rate in the straight pipe section 4 is close to the preset target value; wait for the water flow rate to stabilize for a suitable period of time.

[0034] Step S2: The flow controller host 1 starts timing, and at the same time clears the cumulative flow of the standard flow meter 3 and the flow meter under test 6 to 0; after timing for a suitable period of time, which varies depending on the flow value, the flow controller host 1 stops timing; the flow controller host 1 reads the cumulative flow of the standard flow meter 5 and records it as F; reads the cumulative flow of each flow meter under test 6 and records it as Fv.

[0035] Step S3: Calculate the error of the flow meter 6 under test. The calculation formula is E=(Fv-F) / F*100%; return to step S2 and repeat the data acquisition for a total of 3 times; calculate the average error of the 3 acquisitions Ev=(E1+E2+E3) / 3; calculate the correction coefficient flow value K=K0 / (1+Ev) based on the initial flow coefficient value K0 and the error value Ev.

[0036] Step S4: The calculated correction coefficient value K is transmitted to each corresponding flow meter under test 6 via 485 communication. Since the communication address of each flow meter under test 6 is the same at the factory and cannot be distinguished, a communication address conversion module 7 is added between the flow controller host 1 and the flow meter under test 6 for automatic communication address conversion. The specific steps are as follows:

[0037] Step S4.1: When the flow control instrument host 1 wants to transmit the correction coefficient to the Nth flow meter 6 to be detected, the address value of the Nth flow meter 6 to be detected and the corresponding correction coefficient value and other necessary data are packaged in a data packet, and the data packet is sent to the communication address conversion module 7 through the 485 communication line;

[0038] Step S4.2: After the communication address conversion module 7 receives the data packet, the communication address in the data packet is checked, and the data packet is bound to the corresponding output port according to the address and forwarded. Before forwarding, the communication address in the data packet needs to be modified to the factory default address of the flow meter, and other data remains unchanged;

[0039] Step S4.3: After the Nth flow meter 6 to be detected receives the data packet, the flow coefficient of the Nth flow meter 6 to be detected is modified according to the correction coefficient value in the data packet.

[0040] Step S5: After the coefficient modification is completed, steps S2 to S3 are repeated to calculate a new average error Ev1; if the error Ev1 meets the accuracy requirement, the calibration process is ended, otherwise the above step S4 needs to be repeatedly executed until the error meets the accuracy requirement.

[0041] The above embodiments are only used to illustrate the technical solutions of the present application, but not limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method of simultaneous calibration of a flow meter, characterized by The method comprises the following steps: Step S1: establishing an initial state of flow meter calibration; Step S2: obtaining cumulative flow of the standard flow meter (5) and a group of detected flow meters (6) for a period of time; Step S3: calculating error of the detected flow meter (6) based on the cumulative flow, and calculating a corrected flow coefficient value according to the initial flow coefficient and the error; the error calculation formula is as follows: E=(Fv-F) / F*100% Wherein, E represents the error value, Fv represents the cumulative flow of the detected flow meter (6), and F represents the cumulative flow of the standard flow meter (5); After obtaining the error value, return to step S2 to repeatedly execute collection, and calculate an average error Ev based on the number of collections to calculate the corrected flow coefficient value: K=K0 / (1+Ev) Wherein, K represents the corrected flow coefficient value, and K0 represents the initial flow coefficient value; Step S4: transmitting the corrected coefficient value to the detected flow meter (6) through the communication address conversion, specifically comprising the following steps: Step S4.1: encapsulating the address value corresponding to the detected flow meter (6), the corrected coefficient value and other necessary data in a data packet, and sending the data packet to the communication address conversion module (7); Step S4.2: after receiving the data packet, the communication address conversion module (7) checks the address value in the data packet, binds the data packet with the corresponding output port according to the address value, and forwards the data packet, wherein the address value in the data packet needs to be modified into the factory default address of the flow meter before forwarding; Step S4.3: after receiving the data packet, the detected flow meter (6) modifies its own flow coefficient according to the corrected coefficient value in the data packet; Step S5: after the coefficient modification is completed, steps S2 to S3 are repeatedly executed to calculate a new average error Ev1; if the error Ev1 meets the accuracy requirement, the calibration process is ended, otherwise, the above step S4 needs to be repeatedly executed until the error meets the accuracy requirement.

2. The method of simultaneous calibration of a flow meter of claim 1, wherein: In the step S1, the flow control instrument host (1) controls the opening degree of the water pump (2) and the regulating valve (3) to make the water flow in the flow straight pipe section (4) close to the preset target value.

3. The method of simultaneous calibration of a flow meter of claim 1, wherein: In the step S2, the flow control instrument host (1) starts timing, and clears the cumulative flow of the standard flow meter (5) and the detected flow meter (6) at the same time; the timing is stopped after a period of time based on the flow value size, and the cumulative flow of the standard flow meter (5) and the detected flow meter (6) is read.

4. A simultaneous calibration device of a flowmeter using a simultaneous calibration method of a flowmeter according to claim 1, comprising a flow control instrument host (1), a water pump (2), an adjusting valve (3), and a standard flowmeter (5), characterized in that: The calibration device further comprises a communication address conversion module (7), the flow control instrument host (1) controls the water pump (2) and the regulating valve (3), obtains the cumulative flow of the standard flow meter (5) and a group of detected flow meters (6) within a period of time, calculates the error of the detected flow meter (6) based on the cumulative flow, calculates the corrected flow coefficient value according to the initial flow coefficient and the error, the communication address conversion module (7) obtains the address value corresponding to the detected flow meter (6) and the corrected coefficient value, sends the corrected coefficient value and the factory default address to the corresponding detected flow meter (6) according to the address value, and the detected flow meter (6) modifies its own flow coefficient according to the corrected coefficient value.

5. A simultaneous flow meter calibration apparatus as claimed in claim 4, wherein: The flow control instrument host (1) encapsulates the address value and correction coefficient value corresponding to the flow meter (6) under test and other necessary data in a data packet, and sends the data packet to the communication address conversion module (7); the communication address conversion module (7) checks the address value in the data packet after receiving the data packet, binds the data packet with the corresponding output port according to the address value, and forwards the data packet, wherein the address value in the data packet needs to be modified into the factory default address of the flow meter before forwarding; the flow meter (6) under test receives the data packet, and modifies the flow coefficient of the flow meter according to the correction coefficient value in the data packet.

6. A simultaneous flow meter calibration apparatus as recited in claim 4, wherein: The flow control instrument host (1) calculates the average error Ev by collecting the cumulative flow of the standard flow meter (5) and the flow meter (6) under test for multiple times, calculates the correction flow coefficient value K=K0 / (1+Ev) according to the average error Ev and the initial flow coefficient value K0, and after the coefficient modification is completed, the cumulative flow is collected again to calculate the average error until the average error meets the accuracy requirement.

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