Calibration device for electromagnetic flowmeter and electromagnetic flowmeter

Abstract

The invention provides a calibration device for an electromagnetic flowmeter and the electromagnetic flowmeter. The calibration device for the electromagnetic flowmeter is characterized by comprising a flow velocity sectionalizer for dividing the flow velocity of fluid into a plurality of sections; and a calibration coefficient calculator that calculates a calibration coefficient for each of the plurality of segment segments, respectively. According to the calibration device for the electromagnetic flow meter, the calibration coefficient is generated through the sectional multi-point fitting technology so as to calibrate the electromagnetic flow sensor, and the problem that the difference of the calibration coefficients for the low flow speed is large is solved.

Description

[0001] This application is a divisional application of the invention patent application with application number 201910203153.9 filed on March 18, 2019 and invention name “Calibration device for electromagnetic flowmeter and electromagnetic flowmeter”. Technical Field

[0002] The present disclosure relates to the field of flow meters, and in particular to a calibration device for an electromagnetic flow meter and an electromagnetic flow meter. Background Art

[0003] This section provides background information related to the present disclosure which is not necessarily prior art.

[0004] The ideal electromagnetic flow sensor output is linear with the fluid flow rate, but in reality, it is usually acceptable at high flow rates, but the repeatability and accuracy at low flow rates will deteriorate, and the lower the flow rate, the worse the performance, forming a bell-mouth shape. The existing calibration process usually uses two points for linear regression fitting, which leads to poor accuracy at low flow rates, and even individual flow rates exceed the range allowed by the accuracy and cannot pass the calibration. Therefore, the present disclosure proposes a new calibration device for electromagnetic flowmeters and electromagnetic flowmeters to solve the above-mentioned defects. Summary of the invention

[0005] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0006] One object of the present disclosure is to provide a calibration device for an electromagnetic flowmeter, characterized in that it includes: a flow rate segmenter, which divides the flow rate of a fluid into a plurality of interval segments; and a calibration coefficient calculator, which calculates a calibration coefficient for each of the plurality of interval segments.

[0007] Preferably, the calibration device according to the present disclosure is characterized in that it also includes a flow rate selector, and the flow rate selector selects two or more different flow rates for each of the multiple intervals.

[0008] Preferably, according to the calibration device of the present disclosure, it is characterized in that the calibration coefficient calculator calculates the calibration coefficient by linear regression fitting based on two or more different flow rates of each interval segment in the plurality of interval segments.

[0009] Preferably, according to the calibration device disclosed in the present invention, it is characterized in that the flow rate segmenter divides the flow rate of the fluid into a plurality of interval segments based on the caliber of the electromagnetic flowmeter.

[0010] Preferably, the calibration device according to the present disclosure is characterized in that the number of the multiple interval segments is two.

[0011] Another object of the present disclosure is to provide an electromagnetic flowmeter, characterized in that it includes: a sensor, and a calculator, which calculates the actual flow rate of the fluid based on the output of the sensor and a calibration coefficient determined for the interval segment where the flow rate of the fluid is located.

[0012] Preferably, the electromagnetic flowmeter according to the present disclosure is characterized in that the calculator further includes: a first calculator, which calculates the first flow rate of the fluid based on the calibration coefficient of the reference flow rate of the electromagnetic flowmeter; a flow rate judger, which judges the interval segment where the first flow rate is located; and a second calculator, which recalculates the actual flow rate of the fluid using the calibration coefficient corresponding to the interval segment where the first flow rate is located.

[0013] The calibration device for electromagnetic flowmeter according to the present disclosure uses the segmented multi-point fitting technology to generate calibration coefficients to calibrate the electromagnetic flow sensor, which advantageously overcomes the problem of large differences in calibration coefficients for low flow rates. In other words, by adopting the calibration coefficient based on flow rate, the accuracy at low flow rates is effectively improved. In addition, the calibration coefficient obtained by segmented multi-point fitting is closer to the true value, and the sum of errors at each flow rate point is minimized, which effectively improves the accuracy of the electromagnetic flowmeter.

[0014] Further areas of applicability will become apparent from the description provided herein.The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. In the drawings:

[0016] Figure 1 This is the result of calibrating a 2-inch electromagnetic flowmeter using the default calibration factor (10000050).

[0017] Figure 2 This is the result of linear regression fitting verification using the two points of 1 foot / s and 3 feet / s.

[0018] Figure 3 This is the result of linear regression fitting verification using the two points of 6 feet / s and 10 feet / s.

[0019] Figure 4 A block diagram of a calibration device for an electromagnetic flowmeter according to an embodiment of the present disclosure is shown.

[0020] Figure 5 A block diagram of a calibration device for an electromagnetic flowmeter according to another embodiment of the present disclosure is shown.

[0021] Figure 6 It is the calibration result of the electromagnetic flowmeter with a diameter of 2 inches mentioned above using the calibration device for the electromagnetic flowmeter according to an embodiment of the present disclosure, including the regression equation and straight line obtained by fitting the flow rate data of 1 foot / s, 3 feet / s and 3 feet / s, 6 feet / s, 10 feet / s, and 15 feet / s respectively.

[0022] Figure 7 is based on Figure 6 The results are obtained by linear regression fitting using flow rate data of 1feet / s, 3feet / s and 3feet / s, 6feet / s, 10feet / s, and 15feet / s respectively.

[0023] Figure 8 A block diagram of an electromagnetic flow meter according to an embodiment of the present disclosure is shown.

[0024] Fig. 9 A block diagram of a calculator of an electromagnetic flow meter according to an embodiment of the present disclosure is shown.

[0025] Although the present disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown as examples in the drawings and are described in detail herein. It should be understood, however, that the description of specific embodiments herein is not intended to limit the present disclosure to the specific forms disclosed, but rather, the present disclosure is intended to cover all modifications, equivalents, and alternatives that fall within the spirit and scope of the present disclosure. It should be noted that throughout the several drawings, corresponding reference numerals indicate corresponding parts. DETAILED DESCRIPTION

[0026] Examples of the present disclosure will now be described more fully with reference to the accompanying drawings.The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.

[0027] Example embodiments are provided so that the disclosure will be exhaustive and its scope will be fully conveyed to those skilled in the art. Numerous specific details such as examples of specific components, devices and methods are set forth to provide a detailed understanding of the embodiments of the present disclosure. It will be apparent to those skilled in the art that the example embodiments may be implemented in many different forms without the use of specific details, none of which should be construed as limiting the scope of the present disclosure. In certain example embodiments, well-known processes, well-known structures and well-known techniques are not described in detail.

[0028] Under the condition that the repeatability of the electromagnetic flowmeter sensor is certain, the calibration coefficient directly determines the accuracy of the electromagnetic flowmeter.

[0029] Figure 1 The following table 1 shows the calibration results of a 2-inch electromagnetic flowmeter using the default calibration coefficient (10000050), where the flow rate is about 1 foot / s, 3 feet / s, 6 feet / s, 10 feet / s and 15 feet / s, respectively, and the calibration is performed 5 times.

[0030] Table 1

[0031]

[0032]

[0033] It can be seen from Table 1 that the accuracy deviation is ideal only when the flow rate is 1 foot / s. When the flow rate is about 3 feet / s, 6 feet / s, 10 feet / s and 15 feet / s, the accuracy deviation is not ideal, especially when the flow rate is 3 feet / s, it even exceeds the accuracy allowable range, so it cannot pass the calibration.

[0034] In addition, in the prior art, calibration will also take two flow rate points, such as 1 foot / s and 10 feet / s, run each for 5 times, and then perform linear regression to calculate the gain and offset. However, in the case of low flow rates, this may also cause the accuracy of the sensor to deteriorate and fail the calibration.

[0035] Figure 2 The results are obtained by linear regression fitting calibration using the two points of 1 foot / s and 3 feet / s, where the flow rate is about 1 foot / s, 3 feet / s, 6 feet / s, 10 feet / s and 15 feet / s, and the calibration coefficient is 09680059. The following table 2 is the corresponding data.

[0036] Table 2

[0037]

[0038]

[0039] It can be seen from Table 2 that when the flow rate is about 1 foot / s and 3 feet / s, the accuracy deviation is ideal. When the flow rate is about 6 feet / s and 10 feet / s, the accuracy deviation is not ideal, especially when the flow rate is about 15 feet / s, it is almost close to the required limit.

[0040] Figure 3The results are obtained by linear regression fitting calibration using 6 feet / s and 10 feet / s, where the flow rate is about 1 foot / s, 3 feet / s, 6 feet / s, 10 feet / s and 15 feet / s, and the calibration coefficient is 09659066. Table 3 below shows the corresponding data.

[0041] Table 3

[0042]

[0043]

[0044] It can be seen from Table 3 that when the flow rate is about 3 feet / s, 6 feet / s, 10 feet / s and 15 feet / s, the accuracy deviation is ideal and fully meets the requirements. When the flow rate is about 1 foot / s, the accuracy deviation is poor and exceeds the accuracy allowable range, so it cannot pass the calibration.

[0045] Therefore, a two-point calibration method is adopted, and because the electromagnetic flowmeter sensor is not completely linear, it leads to problems such as low accuracy of the electromagnetic flowmeter sensor, poor accuracy at low flow rates, and failure to pass the calibration in one go during the calibration process.

[0046] Therefore, the present disclosure proposes a new calibration device for an electromagnetic flowmeter and an electromagnetic flowmeter to solve the above problems.

[0047] According to one embodiment of the present disclosure, a calibration device for an electromagnetic flowmeter is provided, characterized in that it includes: a flow rate segmenter, which divides the flow rate of a fluid into a plurality of interval segments; and a calibration coefficient calculator, which calculates a calibration coefficient for each of the plurality of interval segments.

[0048] Figure 4 A block diagram of a calibration device for an electromagnetic flowmeter according to an embodiment of the present disclosure is shown.

[0049] like Figure 4 As shown, the calibration device 100 provided in this embodiment may include a flow rate segmenter 101 and a calibration coefficient calculator 103 .

[0050] The flow rate segmenter 101 can divide the flow rate of the fluid into multiple intervals. According to one embodiment of the present disclosure, the flow rate segmenter 101 can divide the flow rate of the fluid into two intervals, for example, with 3 feet / s as the boundary, the flow rate below 3 feet / s is one interval, and the flow rate above 3 feet / s is one interval. It should be clear to those skilled in the art that the two intervals and the flow rate limit of 3 feet / s are only exemplary, and those skilled in the art can certainly divide more intervals as needed, and those skilled in the art can certainly set other limits such as 2.5 feet / s, 3.5 feet / s, etc. as needed.

[0051] Next, the calibration coefficient calculator 103 can calculate the calibration coefficient for each of the multiple intervals. For example, the calibration coefficient calculator 103 can calculate a calibration coefficient for a flow rate below 3 feet / s, and the calibration coefficient calculator 103 can calculate a calibration coefficient for a flow rate above 3 feet / s.

[0052] The calibration device for electromagnetic flowmeter according to the present disclosure uses the segmented multi-point fitting technology to generate calibration coefficients to calibrate the electromagnetic flow sensor, which advantageously overcomes the problem of large differences in calibration coefficients for low flow rates. That is, by using the calibration coefficient based on flow rate, the accuracy at low flow rates is effectively improved.

[0053] According to an embodiment of the present disclosure, the calibration device for the electromagnetic flowmeter may further include a flow rate selector, which selects two or more different flow rates for each of the multiple intervals.

[0054] Figure 5 A block diagram of a calibration device for an electromagnetic flowmeter according to an embodiment of the present disclosure is shown.

[0055] like Figure 5 As shown, the calibration device 200 provided in this embodiment may further include a flow rate selector 102 in addition to the flow rate segmenter 101 and the calibration coefficient calculator 103 .

[0056] The flow rate selector 102 can select two or more different flow rates for each of the multiple intervals. Taking the flow rate limit of 3 feet / s as an example, when the flow rate is below 3 feet / s, the flow rate selector 102 can select two flow rate points such as 1 feet / s and 3 feet / s to calculate the calibration coefficient; when the flow rate is above 3 feet / s, the flow rate selector 102 can select two flow rate points such as 5 feet / s and 10 feet / s to calculate the calibration coefficient. Here, it should be clear to those skilled in the art that the selection of flow rate points such as 1 feet / s and 3 feet / s and 5 feet / s and 10 feet / s is only exemplary, and those skilled in the art can set other flow rate points as needed. Of course, the flow rate limit of 3 feet / s is included in the case below the limit, and those skilled in the art should be clear that the flow rate limit can also be included in the case above the limit.

[0057] As described above, the calibration device for an electromagnetic flowmeter according to the present disclosure uses a segmented multi-point fitting technique to generate calibration coefficients to calibrate the electromagnetic flow sensor, which advantageously overcomes the problem of large differences in calibration coefficients for low flow rates.

[0058] According to an embodiment of the present disclosure, the calibration coefficient calculator may calculate the calibration coefficient by linear regression fitting based on two or more different flow rates of each of the plurality of intervals.

[0059] For example, Figure 6 It is based on the calibration results of the above-mentioned electromagnetic flowmeter with a diameter of 2 inches, including the regression equation and straight line obtained by fitting the flow rate data of 1 foot / s, 3 feet / s and 3 feet / s, 6 feet / s, 10 feet / s, and 15 feet / s respectively:

[0060] 1feet / s, 3feet / s: y=96.799x+0.9262

[0061] 3feet / s, 6feet / s, 10feet / s, 15feet / s: y=96.524x+1.8796.

[0062] Then, calculate the new calibration coefficients according to this equation:

[0063] 1feet / s, 3feet / s: Gain = 96.80, offset: 5.0+0.9262=5.9, new calibration coefficient: 09680059.

[0064] 3feet / s, 6feet / s, 10feet / s, 15feet / s: Gain = 96.52, offset: 5.0+1.8796=6.9. The new calibration coefficient is: 09652069.

[0065] Figure 7 The results are obtained by linear regression fitting using the flow rate data of 1 foot / s, 3 feet / s and 3 feet / s, 6 feet / s, 10 feet / s, and 15 feet / s, respectively, where the calibration coefficients are 09680059 and 09652069, respectively. Table 4 below is the corresponding data.

[0066] Table 4

[0067]

[0068] It can be seen from Table 4 above that when the flow rates are about 1 foot / s, 3 feet / s, 6 feet / s, 10 feet / s and 15 feet / s, the accuracy deviations are good and fully meet the accuracy requirements.

[0069] Here, it should be clear to those skilled in the art that the selection of the above flow rate points is exemplary and the present disclosure is not limited thereto. In addition, due to the actual situation, there is a certain reasonable range of error. For example, the 15 feet / s described in the present disclosure may be 14.8 feet / s or 14.7 feet / s in actual measurement, but it should be clear to those skilled in the art that within the reasonable error range, the present disclosure refers to 15 feet / s.

[0070] In addition, according to an embodiment of the present disclosure, the flow rate segmenter can divide the flow rate of the fluid into multiple intervals based on the caliber of the electromagnetic flowmeter. According to an embodiment of the present disclosure, the flow rate of the fluid is divided into two intervals (1feet / s, 3feet / s) and (3feet / s, 6feet / s, 10feet / s, 15feet / s) based on a 2-inch caliber electromagnetic flowmeter. However, it should be clear to those skilled in the art that the embodiments of the present disclosure are merely exemplary, and the present disclosure is not limited thereto. Those skilled in the art can of course divide the flow rate of the fluid according to electromagnetic flowmeters of different calibers, and select different flow rate points for linear regression fitting.

[0071] The calibration device for electromagnetic flowmeter according to the present disclosure uses the segmented multi-point fitting technology to generate calibration coefficients and calibrate the electromagnetic flow sensor, which advantageously overcomes the problem of large differences in calibration coefficients for low flow rates. That is, by adopting the calibration coefficient based on flow rate, the accuracy at low flow rates is effectively improved. In addition, the calibration coefficient obtained by segmented multi-point fitting is closer to the true value, and the sum of errors at each flow rate point is minimized, which effectively improves the accuracy of the electromagnetic flowmeter.

[0072] According to one embodiment of the present disclosure, an electromagnetic flowmeter is also provided, characterized in that it includes: a sensor, and a calculator, which calculates the actual flow rate of the fluid based on the output of the sensor and a calibration coefficient determined for the interval segment where the flow rate of the fluid is located.

[0073] like Figure 8 As shown, the electromagnetic flow meter 300 may include a sensor 301 and a calculator 302 .

[0074] The calculator 302 can calculate the actual flow rate of the fluid based on the output of the sensor 301 and the calibration coefficient determined for the interval where the flow rate of the fluid is located. The calibration coefficient can be calculated in the manner of calculating the calibration coefficient for each interval as described above, and the specific implementation is not repeated here.

[0075] According to one embodiment of the present disclosure, an electromagnetic flowmeter is provided, characterized in that the calculator of the electromagnetic flowmeter further includes: a first calculator, which calculates a first flow rate of the fluid based on a calibration coefficient of a reference flow rate of the electromagnetic flowmeter; a flow rate judger, which judges an interval segment where the first flow rate is located; and a second calculator, which recalculates the actual flow rate of the fluid using the calibration coefficient corresponding to the interval segment where the first flow rate is located.

[0076] According to another embodiment of the present disclosure, an electromagnetic flowmeter is provided, characterized in that the calculator of the electromagnetic flowmeter includes: a first calculator, which calculates a first flow rate of the fluid based on a calibration coefficient of a reference flow rate interval of the electromagnetic flowmeter; a flow rate judger, which judges whether the first flow rate belongs to the reference flow rate interval; and a second calculator, which, if the first flow rate does not belong to the reference flow rate interval, recalculates the actual flow rate of the fluid based on a calibration coefficient determined for the interval in which the first flow rate is located.

[0077] Fig. 9 A block diagram of a calculator of an electromagnetic flow meter according to an embodiment of the present disclosure is shown.

[0078] like Fig. 9As shown, the calculator 302 according to the present disclosure may further include a first calculator 3021 , a flow rate determiner 3022 , and a second calculator 3023 .

[0079] The first calculator 3021 can calculate the first flow velocity of the fluid based on the calibration coefficient of the reference flow velocity interval of the electromagnetic flowmeter. For example, assuming that the reference flow velocity interval is a flow velocity above 3 feet / s, the first calculator 3021 can first calculate the initial flow velocity of the fluid based on the calibration coefficient for the flow velocity above 3 feet / s.

[0080] Next, the flow rate determiner 3022 may determine whether the preliminary flow rate belongs to the reference flow rate interval, that is, determine whether the preliminary flow rate is greater than 3 feet / s.

[0081] Then, when the preliminary flow velocity does not belong to the reference flow velocity interval, that is, when the preliminary flow velocity is not greater than 3 feet / s, the second calculator 3023 can recalculate the actual flow velocity of the fluid based on the calibration coefficient determined by the flow velocity in the interval where the preliminary flow velocity is located, that is, less than 3 feet / s.

[0082] Here, it should be clear to those skilled in the art that the selection of the above flow rate intervals is only exemplary, and the present disclosure is not limited thereto. Those skilled in the art can certainly set different multiple intervals according to actual conditions. Similarly, the calibration coefficient can be calculated in the manner of calculating the calibration coefficient for each interval as described above, and the specific implementation method will not be repeated here.

[0083] Using the electromagnetic flowmeter according to the present disclosure, the calibration is performed by adopting a segmented multi-point fitting method, which not only effectively improves the overall accuracy of the electromagnetic flowmeter sensor, but also solves the problem that a small flow rate easily exceeds the required range.

[0084] Although the embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings, it should be understood that the embodiments described above are only used to illustrate the present disclosure and do not constitute a limitation of the present disclosure. For those skilled in the art, various modifications and changes can be made to the above embodiments without departing from the essence and scope of the present disclosure. Therefore, the scope of the present disclosure is limited only by the attached claims and their equivalent meanings.

Claims

1. A calibration device for an electromagnetic flowmeter, characterized in that: include: A flow rate segmenter, which divides the flow rate of the fluid into a plurality of interval segments; as well as A calibration coefficient calculator is configured to calculate a calibration coefficient for each of the plurality of interval segments.

2. The calibration device according to claim 1, characterized in that: The calibration device further comprises a flow rate selector, which selects two or more different flow rates for each of the plurality of intervals.

3. The calibration device according to claim 2, characterized in that: The calibration coefficient calculator calculates the calibration coefficient using linear regression fitting based on two or more different flow rates of each of the plurality of intervals.

4. The calibration device according to claim 1, characterized in that: The flow rate segmenter divides the flow rate of the fluid into a plurality of interval segments based on the caliber of the electromagnetic flow meter.

5. The calibration device according to any one of claims 1 to 5, characterized in that: The number of the plurality of intervals is two.

6. An electromagnetic flowmeter, characterized in that: include: Sensors, and A calculator calculates the actual flow rate of the fluid based on the output of the sensor and a calibration coefficient determined for the interval in which the flow rate of the fluid is located.

7. The electromagnetic flowmeter according to claim 6, characterized in that: The calculator further comprises: a first calculator for calculating a first flow rate of the fluid based on a calibration coefficient of a reference flow rate of the electromagnetic flowmeter; a flow rate determiner for determining a section in which the first flow rate is located; and A second calculator is configured to recalculate the actual flow rate of the fluid by using a calibration coefficient corresponding to the interval where the first flow rate is located.

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