A multimeter and recalibration method thereof

Abstract

A multimeter and a recalibration method thereof, relating to the field of measurement technology. The method comprises: obtaining an instruction for setting a range to be calibrated under a measurement function to be calibrated of the multimeter; selecting at least two calibration points under the range to be calibrated; obtaining a stable signal at each calibration point to generate a calibrated measurement value corresponding to each calibration point at each calibration point; for each calibration point: obtaining a real-time measurement value of the calibration point, grouping the real-time measurement values ​​corresponding to the calibration point to generate a corresponding measurement group; calculating the fluctuation difference of each measurement group, taking the measurement group with the smallest fluctuation difference as a reference group, calculating the average value of each real-time measurement value in the reference group to determine a real-time measurement stability value; determining a calibration coefficient according to the real-time measurement stability value and the calibrated measurement value of each calibration point under a preset linear relationship, and recalibrating the multimeter using the calibration coefficient to provide a simpler and more convenient recalibration method.

Description

Technical Field

[0001] The present application relates to the field of measurement technology, and in particular to a multimeter and a recalibration method thereof. Background Art

[0002] The multimeter is calibrated before it leaves the factory to compensate for the data. As the multimeter ages, the electronic components of the device circuit will age, resulting in reduced sensitivity. Or, due to magnetic fields or temperature offsets in the natural environment around the site of use, the sensitivity and accuracy of the multimeter will decrease, thus affecting the performance of the multimeter. Therefore, the multimeter needs to be recalibrated.

[0003] The existing processing methods are to return the multimeter to the original production factory for recalibration or to go to a local calibration agency for calibration. For the current processing methods, there is a transportation process, which increases costs, especially the problem of recalibration at the calibration agency, which increases cost consumption and time costs. If there is a deviation caused by uncontrollable strong interference such as natural factors in a specific use environment, even if the above two methods are used, data calibration cannot be achieved. Summary of the invention

[0004] The main technical problem solved by the present application is to provide a multimeter capable of manual and timely recalibration and a recalibration method thereof.

[0005] According to a first aspect, an embodiment provides a method for recalibrating a multimeter, comprising:

[0006] Under the measurement function to be calibrated of the multimeter, obtain an instruction for setting the range to be calibrated;

[0007] Select at least two calibration points in the range to be calibrated;

[0008] Acquiring a stable signal at each calibration point to generate a calibration measurement value corresponding to each calibration point at each calibration point;

[0009] For each calibration point:

[0010] The real-time measurement values ​​of the calibration points are obtained, and the real-time measurement values ​​corresponding to the calibration points are grouped to generate corresponding measurement groups; the fluctuation difference of each measurement group is calculated, and the measurement group with the smallest fluctuation difference is used as the reference group, and the average value of each real-time measurement value in the reference group is calculated to determine the real-time measurement stability value;

[0011] Under a preset linear relationship, the calibration coefficient is determined according to the real-time measurement stability value and the calibrated measurement value of each calibration point, and the multimeter is recalibrated using the calibration coefficient.

[0012] In one embodiment, obtaining real-time measurement values ​​of calibration points and grouping the real-time measurement values ​​corresponding to the calibration points to generate corresponding measurement groups includes:

[0013] A first set number of continuous real-time measurement values ​​are grouped into one group, and a second set number of continuous real-time measurement values ​​in adjacent measurement groups are the same, wherein the number of real-time measurement values ​​in each measurement group is the same.

[0014] In one embodiment, calculating the fluctuation difference of each measurement group includes:

[0015] The standard deviation of each measurement group is calculated, and the fluctuation difference of each measurement group is determined according to the standard deviation of each measurement group.

[0016] In one embodiment, the calibration coefficient includes a coefficient value and an offset value. Under a linear relationship, the coefficient value representing the slope of the linear relationship and the offset value representing the intercept of the linear relationship are determined according to the real-time measurement stability value and the calibration measurement value of each calibration point.

[0017] In one embodiment, the difference between the calibration points is greater than a set threshold.

[0018] According to a second aspect, an embodiment provides a multimeter, comprising:

[0019] A calibration setting module, used to set the measurement function to be calibrated in the calibration setting module, and obtain an instruction for setting the range to be calibrated under the measurement function to be calibrated, and select at least two calibration points under the range to be calibrated;

[0020] A measurement data acquisition module, for each calibration point, the measurement data acquisition module acquires the real-time measurement value of the calibration point, and groups the real-time measurement values ​​corresponding to the calibration point to generate corresponding measurement groups;

[0021] The data processing module is used to calculate the fluctuation difference of each measurement group, take the measurement group with the smallest fluctuation difference as the benchmark group, calculate the average value of each real-time measurement value in the benchmark group to determine the real-time measurement stability value; the data processing module also obtains the stable signal at each calibration point, and generates the calibrated measurement value corresponding to each calibration point according to the stable signal; under the preset linear relationship, the data processing module determines the calibration coefficient according to the real-time measurement stability value and the calibrated measurement value of each calibration point, and uses the calibration coefficient to recalibrate the multimeter.

[0022] In one embodiment, the measurement data acquisition module groups a first set number of continuous real-time measurement values ​​into one group, and a second set number of continuous real-time measurement values ​​in adjacent measurement groups are the same, wherein the number of real-time measurement values ​​in each measurement group is the same.

[0023] In one embodiment, the data processing module calculates the standard deviation of each measurement group, and determines the fluctuation difference of each measurement group according to the standard deviation of each measurement group.

[0024] In one embodiment, the data processing module determines the coefficient value representing the slope of the linear relationship and the offset value representing the intercept of the linear relationship according to the real-time measurement stability value and the calibration measurement value of each calibration point under the linear relationship.

[0025] In one embodiment, in the calibration setting module, the difference between the calibration points is greater than a set threshold.

[0026] According to the multimeter and the recalibration method thereof of the above-mentioned embodiment, a range to be calibrated is set under the measurement function to be calibrated in the multimeter, at least two calibration points are selected in the range to be calibrated, the real-time measurement value of each calibration point is obtained, and the real-time measurement values ​​of each calibration point are grouped to generate corresponding measurement groups. The fluctuation difference of each measurement group is calculated, and the measurement group with the smallest fluctuation difference is used as the reference group. The average value is calculated for each real-time measurement value in the reference group, so as to determine the real-time measurement stability value. Under the preset linear relationship, the calibration coefficient for recalibrating the multimeter is determined according to the real-time measurement stability value and the calibration measurement value of each calibration point. In the recalibration process, the present application obtains a more stable reference group in a manner with the smallest fluctuation difference, and uses the reference group as the data for recalibration in the form of an average value. The data at this time can eliminate unstable factors such as the instability of the multimeter itself and external signal interference, so that the recalibrated data is more stable. Furthermore, the recalibration method provided in the present application can be used to simply and repeatedly recalibrate the multimeter anytime and anywhere, which is easy to operate and saves time and cost. In addition, the multimeter can also be recalibrated in a specific environment to eliminate the deviation effect of the specific environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a flow chart of a multimeter recalibration method in an embodiment;

[0028] Figure 2 A structural diagram of a multimeter in another embodiment;

[0029] Figure 3 is an execution flow chart of multimeter calibration in one embodiment;

[0030] Figure 4 The flowchart of calibrating a multimeter at various calibration points in one embodiment is shown. DETAILED DESCRIPTION

[0031] The present application is further described in detail below by specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments adopt associated similar element numbers. In the following embodiments, many detailed descriptions are intended to enable the present application to be better understood. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, and methods. In some cases, some operations related to the present application are not shown or described in the specification, in order to avoid the core part of the present application being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0032] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various implementations. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a required sequence, unless otherwise specified that a certain sequence must be followed.

[0033] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0034] Please refer to Figure 1 In one embodiment, a method for recalibrating a multimeter is provided, comprising the following steps:

[0035] Step S110: selecting at least two calibration points within the range to be calibrated.

[0036] In one embodiment, the multimeter is a multifunctional electronic measuring tool that can be used to measure various electrical parameters. During the measurement process of the multimeter, the main measuring functions include DC voltage, AC voltage, DC current, AC current, resistance, diode test, capacitance and other functions. When the multimeter needs to be calibrated, any one of the above measurement functions that needs to be calibrated is selected as the measurement function to be calibrated, and an instruction for setting the range to be calibrated is obtained in the measurement function to be calibrated, and the range to be calibrated is set according to the instruction. For example, when DC voltage is used as the measurement function to be calibrated, any range in the measurement range of DC voltage ranging from millivolts to kilovolts is selected as the range to be calibrated.

[0037] In one embodiment, after determining the range to be calibrated under the measurement function to be calibrated, at least two calibration points are selected in the range to be calibrated, and the difference between the calibration points is greater than a set threshold, and the larger the better. For example, DC voltage is used as the measurement function to be calibrated, 200mv is used as the range to be calibrated, and when two calibration points are selected in the range to be calibrated, the first calibration point can be set at 10mv, and the second calibration point can be set at 180mv. The farther the distance between the calibration points, the more accurate the calibration between the range to be calibrated.

[0038] Step S120: Obtain the calibration measurement value corresponding to each calibration point.

[0039] In one embodiment, when a user recalibrates a multimeter, a signal device that can output the measurement function that needs to be calibrated for the recalibration of the multimeter and a high-precision measuring instrument for recalibrating the multimeter are required. For example, when the multimeter needs to recalibrate the voltage measurement function, a voltage source that can stably output voltage is required; when the multimeter needs to recalibrate the resistance measurement function, a resistance device can be prepared. The high-precision measuring instrument is used as a calibration calibrator to measure the stable signal output by the signal device to determine the calibration measurement value corresponding to the stable signal.

[0040] In one embodiment, a signal device is used to output a stable signal corresponding to each calibration point at each calibration point, and then a high-precision measuring instrument is used to obtain the calibration measurement value corresponding to each calibration point. Similarly, taking DC voltage as the measurement function to be calibrated, 200mv as the range to be calibrated, the first calibration point is set at 10mv, and the second calibration point is set at 180mv. For example, a voltage source is used to apply a stable signal at 10mv and 180mv respectively. The stable signal is the voltage signal applied by the voltage source at 10mv and 180mv respectively, and the high-precision measuring instrument is used to measure the stable signal to determine the calibration measurement value y corresponding to each calibration point. i .

[0041] In one embodiment, after the calibration points and calibrated measurements are determined, the following steps are performed at each calibration point.

[0042] Step S130: acquiring real-time measurement values ​​of calibration points, and grouping the real-time measurement values ​​corresponding to the calibration points to generate a plurality of measurement groups.

[0043] In one embodiment, after the calibration point is set, the multimeter is manually recalibrated, thereby obtaining a number of real-time measurement values ​​of the multimeter at the calibration point, and grouping these real-time measurement values ​​to generate corresponding measurement groups.

[0044] In one embodiment, when grouping a plurality of real-time measurement values, a first set number of consecutive real-time measurement values ​​are grouped into one group, a second set number of consecutive real-time measurement values ​​in adjacent measurement groups are the same, and the number of real-time measurement values ​​in each measurement group is the same.

[0045] In one embodiment, the sampling integration time of the multimeter is set to 10 PLC, that is, 10 power line cycles, that is, a real-time measurement data is collected every 200ms. Under the condition that the input mains frequency is 50Hz, it takes more than 4s to complete the input interaction operation of the actual calibration data UI button. Therefore, according to the calculation, 20 real-time measurement values ​​can be obtained at each calibration point of the manual calibration of the multimeter. The 20 real-time measurement values ​​are: [x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15, x16, x17, x18, x19, x20, x21, x22, x23, x24, x25, x26, x27, x28, x29, x30, x31, x32, x33, x34, x35, x36, x37, x38, x39, x40, x41, x42, x43, x44, x45, x46, x47, x48, x49, x50, x51, x52, x53, x54, x55, x56, x57, x58, x60, x61, x62, x63, x64, x65 10 、x 11 、x 12 、x 13 、x 14 、x 15 、x 16 、x 17 、x 18 、x 19 、x 20 ].

[0046] In one embodiment, after determining 20 real-time measurement values, 11 consecutive real-time measurement values ​​are divided into a measurement group, and a total of 10 groups are divided, and the consecutive 10 real-time measurement values ​​in two adjacent measurement groups are the same. Therefore, the 10 measurement groups obtained are: [x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15, x16, x17, x18, x19, x20, x21, x22, x23, x24, x25, x26, x27, x28, x29, x30, x31, x32, x33, x34, x35, x36, x37, x38, x39, x40, x41, x42, x43, x44, x45, x46, x47, x4 10 、x 11 ], [x2, x3, x4, x5, x6, x7, x8, x9, x 10 、x 11 、x 12 ], [x3, x4, x5, x6, x7, x8, x9, x 10 、x 11 、x 12 、x 13 ], [x4, x5, x6, x7, x8, x9, x 10 、x 11 、x 12 、x 13 、x 14 ], [x5, x6, x7, x8, x9, x 10 、x 11 、x 12 、x 13 、x 14 、x 15 ], [x6, x7, x8, x9, x10 、x 11 、x 12 、x 13 、x 14 、x 15 、x 16 ], [x7, x8, x9, x 10 、x 11 、x 12 、x 13 、x 14 、x 15 、x 16 、x 17 ], [x8, x9, x 10 、x 11 、x 12 、x 13 、x 14 、x 15 、x 16 、x 17 、x 18 ]、[x9、x 10 、x 11 、x 12 、x 13 、x 14 、x 15 、x 16 、x 17 、x 18 、x 19 ] and [x 10 、x 11 、x 12 、x 13 、x 14 、x 15 、x 16 、x 17 、x 18 、x 19 、x 20 ].

[0047] It should be noted that when the sampling integration time set for the multimeter is different, the number of real-time measurement values ​​is not the same. In actual use, the number of measurement groups may also be different, and the number of real-time measurement values ​​contained in each group and the number of the same real-time measurement values ​​between two adjacent measurement groups may also be adjusted differently according to engineering practice, and there is no mandatory limitation.

[0048] Step S140: Calculate the fluctuation difference of each measurement group, and take the measurement group with the smallest fluctuation difference as the reference group.

[0049] In one embodiment, the standard deviation of each measurement group is calculated, and the fluctuation difference of each measurement group is determined according to the standard deviation of each measurement group. It should be noted that in addition to calculating the standard deviation of each measurement group, the variance, interquartile range, mean absolute deviation and median absolute deviation of each measurement group can also be calculated, and the fluctuation difference is determined according to the variance, interquartile range, mean absolute deviation and median absolute deviation of each measurement group.

[0050] In one embodiment, after calculating the standard deviation of each measurement group, a measurement group with the smallest standard deviation is used as a reference group, and the average value of each real-time measurement value in the reference group is calculated to determine the real-time measurement stability value m i .

[0051] In one embodiment, taking the above 10 measurement groups and the standard deviation to determine the fluctuation difference as an example, the standard deviation and the average value of the 10 measurement groups are calculated respectively, which are [σ1, μ1], [σ2, μ2], [σ3, μ3], [σ4, μ4], [σ5, μ5], [σ6, μ6], [σ7, μ7], [σ8, μ8], [σ9, μ9] and [σ 10 , μ 10 ]. Compare the standard deviations σ in these 10 measurement groups, take the measurement group with the smallest standard deviation σ as the benchmark group, and take the average value μ of the benchmark group as the real-time measurement stability value m i . The standard deviation and mean are calculated using the following formula:

[0052]

[0053]

[0054] Where σ represents the standard deviation, N represents the number of real-time measurement values, and x i represents the i-th real-time measurement value, and μ represents the average value.

[0055] Step S150: Under a preset linear relationship, a calibration coefficient is determined according to the real-time measurement stability value and the calibrated measurement value of each calibration point.

[0056] In one embodiment, the calibration measurement value y corresponding to each calibration point is obtained. i and real-time measurement stability value m i , through a linear relationship y i =k n ×m i +b n Calculate the calibration coefficient for the range to be calibrated. The calibration measurement value y is determined at each calibration point. i and real-time measurement stability value m i , the calibration measurement values ​​y of at least two calibration points i and real-time measurement stability value mi Substitute into the linear relationship to determine k n and b n , where k n The coefficient value representing the slope of a linear relationship, b n The offset value representing the intercept of a linear relationship.

[0057] Please refer to Figure 2 In another embodiment, a multimeter 10 is provided, which includes a calibration setting module 11, a measurement data acquisition module 12 and a data processing module 13.

[0058] In one embodiment, please refer to Figure 3 This is an execution flow chart of the calibration of the multimeter 10. When the multimeter 10 needs to be calibrated, the user enters the recalibration interface of the multimeter 10, sets the measurement function to be calibrated in the calibration setting module 11, and sets the range to be calibrated under the measurement function to be calibrated.

[0059] In one embodiment, during the measurement process of the multimeter, the main measurement functions include DC voltage, AC voltage, DC current, AC current, resistance, diode test, capacitance, etc. When the multimeter needs to be calibrated, any one of the above measurement functions that needs to be calibrated is selected as the measurement function to be calibrated, an instruction for setting the range to be calibrated is obtained, and the range to be calibrated is set according to the instruction.

[0060] In one embodiment, after determining the range to be calibrated under the measurement function to be calibrated, the calibration setting module 11 selects at least two calibration points in the range to be calibrated, and the difference between the calibration points is greater than a set threshold, and the larger the better.

[0061] In one embodiment, the annunciator is connected to the measuring terminal of the multimeter 10. According to the interface display, the annunciator outputs a suitable range value of the calibration point prompt. The user can select the calibration point within the suitable range value or not within the suitable range value.

[0062] In one embodiment, a high-precision measuring instrument is used to synchronize the signal device with the calibration measurement value y corresponding to each calibration point. i For each calibration point, refer to Figure 4 It is a flow chart of calibrating the multimeter at each calibration point. The measurement data acquisition module 12 acquires the real-time measurement values ​​of the calibration points and groups the real-time measurement values ​​corresponding to the calibration points to generate a plurality of measurement groups.

[0063] In one embodiment, the measurement data acquisition module 12 acquires a plurality of real-time measurement values ​​of the multimeter 10 at the calibration point, and groups the real-time measurement values ​​to generate a corresponding measurement group. When grouping the plurality of real-time measurement values, the measurement data acquisition module 12 groups a first set number of continuous real-time measurement values ​​into one group, a second set number of continuous real-time measurement values ​​in adjacent measurement groups are the same, and the number of real-time measurement values ​​in each measurement group is the same.

[0064] In one embodiment, the data processing module 13 is used to calculate the fluctuation difference of each measurement group, take the measurement group with the smallest fluctuation difference as the benchmark group, and calculate the average value of each real-time measurement value in the benchmark group to determine the real-time measurement stability value.

[0065] In one embodiment, the data processing module 13 calculates the standard deviation of each measurement group, and determines the fluctuation difference of each measurement group based on the standard deviation of each measurement group. It should be noted that in addition to calculating the standard deviation of each measurement group, the data processing module 13 can also calculate the variance, interquartile range, mean absolute deviation and median absolute deviation of each measurement group. The data processing module 13 determines the fluctuation difference based on the variance, interquartile range, mean absolute deviation and median absolute deviation of each measurement group. After calculating the standard deviation of each measurement group, the data processing module 13 uses the group of measurement groups with the smallest standard deviation as the benchmark group, and calculates the average value of each real-time measurement value in the benchmark group, thereby determining the real-time measurement stability value m i .

[0066] In one embodiment, the data processing module 13 further obtains a stable signal at each calibration point, and generates a calibration measurement value corresponding to each calibration point according to the stable signal. Under a preset linear relationship, the data processing module 13 determines a calibration coefficient according to the real-time measurement stable value and the calibration measurement value of each calibration point, and recalibrates the multimeter using the calibration coefficient.

[0067] In one embodiment, a signal device is used to output a stable signal corresponding to each calibration point at each calibration point, and then a high-precision measuring instrument is used to obtain a calibration measurement value y corresponding to each calibration point. i The data processing module 13 obtains the calibration measurement value y corresponding to each calibration point i and real-time measurement stability value m i , through a linear relationship y i =k n ×m i +b n The calibration coefficients under the range to be calibrated are calculated. The data processing module 13 determines the calibration measurement value y at each calibration point. i and real-time measurement stability value m i , the calibration measurement values ​​y of at least two calibration points i and real-time measurement stability value mi Substitute into the linear relationship to determine k n and b n , where k n The coefficient value representing the slope of a linear relationship, b n The offset value representing the intercept of a linear relationship.

[0068] In one embodiment, after completing the calibration of each calibration point, if there are other ranges that need to be calibrated under the measurement function to be calibrated, the range to be calibrated is reset and recalibrated. If there are no other ranges that need to be calibrated under the measurement function to be calibrated, it is determined whether there are other measurement functions to be calibrated that need to be calibrated. If necessary, the measurement function to be calibrated is reset in the calibration setting module 11. If not, the calibration coefficient calculated this time is stored as user calibration data. At this time, the multimeter will prompt whether to switch from the manufacturer calibration data to the user calibration data to take effect for this recalibration data.

[0069] In one embodiment, the multimeter 10 is calibrated when it leaves the factory, and the factory calibration coefficient of each segment of real-time measurement data is the coefficient value k f and offset value b f After manual recalibration using the multimeter and the recalibration method provided by the present application, when the original data directly measured by the multimeter 10 from the measuring terminal is x, the compensation formula for the original measured data by calling the user calibration data is y=k n (k y ×x+b f )+b n During the recalibration process, the present application retains the original factory calibration data, allowing the user to call it as needed, and limits the range of coefficients and offset values ​​to prevent users from deliberately calibrating to obtain data with too large deviations.

[0070] Those skilled in the art will appreciate that all or part of the functions of the various methods in the above-mentioned embodiments can be implemented by hardware or by computer programs. When all or part of the functions in the above-mentioned embodiments are implemented by computer programs, the program can be stored in a computer-readable storage medium, and the storage medium can include: read-only memory, random access memory, disk, optical disk, hard disk, etc., and the program is executed by a computer to implement the above-mentioned functions. For example, the program is stored in the memory of the device, and when the program in the memory is executed by the processor, all or part of the above-mentioned functions can be implemented. In addition, when all or part of the functions in the above-mentioned embodiments are implemented by computer programs, the program can also be stored in a storage medium such as a server, another computer, disk, optical disk, flash disk or mobile hard disk, and can be downloaded or copied and saved in the memory of the local device, or the system of the local device is updated, and when the program in the memory is executed by the processor, all or part of the functions in the above-mentioned embodiments can be implemented.

[0071] The above specific examples are used to illustrate the present application, which is only used to help understand the present application and is not intended to limit the present application. For technicians in the technical field to which the present application belongs, they can also make some simple deductions, deformations or substitutions based on the ideas of the present application.

Claims

1. A method for recalibrating a multimeter, characterized in that: include: Under the measurement function to be calibrated of the multimeter, obtain an instruction for setting the range to be calibrated; Selecting at least two calibration points within the range to be calibrated; Acquiring a stable signal at each calibration point to generate a calibration measurement value corresponding to each calibration point at each calibration point; For each calibration point: Acquire real-time measurement values ​​of the calibration points, and group a first set number of continuous real-time measurement values ​​into a group to generate corresponding measurement groups; wherein a second set number of continuous real-time measurement values ​​in adjacent measurement groups are the same, and the number of real-time measurement values ​​in each measurement group is the same; Calculate the fluctuation difference of each measurement group, take the measurement group with the smallest fluctuation difference as the reference group, and calculate the average value of each real-time measurement value in the reference group to determine the real-time measurement stability value; Under a preset linear relationship, a calibration coefficient is determined according to the real-time measurement stability value and the calibrated measurement value of each calibration point, and the multimeter is recalibrated using the calibration coefficient.

2. The multimeter recalibration method according to claim 1, characterized in that: The calculating of the fluctuation difference of each measurement group comprises: The standard deviation of each measurement group is calculated, and the fluctuation difference of each measurement group is determined according to the standard deviation of each measurement group.

3. The multimeter recalibration method according to claim 2, characterized in that: The calibration coefficient includes a coefficient value and an offset value. Under a linear relationship, the coefficient value representing the slope of the linear relationship and the offset value representing the intercept of the linear relationship are determined according to the real-time measurement stability value and the calibration measurement value of each calibration point.

4. The multimeter recalibration method according to claim 1, characterized in that: The difference between the calibration points is greater than a set threshold.

5. A multimeter, characterized in that: include: A calibration setting module, used to set a measurement function to be calibrated in the calibration setting module, and obtain an instruction for setting a range to be calibrated under the measurement function to be calibrated, and select at least two calibration points under the range to be calibrated; A measurement data acquisition module, for each calibration point, the measurement data acquisition module acquires a real-time measurement value of the calibration point, and groups a first set number of continuous real-time measurement values ​​into one group to generate corresponding measurement groups; wherein a second set number of continuous real-time measurement values ​​in adjacent measurement groups are the same, and the number of real-time measurement values ​​in each measurement group is the same; The data processing module is used to calculate the fluctuation difference of each measurement group, take the measurement group with the smallest fluctuation difference as the benchmark group, calculate the average value of each real-time measurement value in the benchmark group to determine the real-time measurement stability value; the data processing module also obtains the stable signal at each calibration point, and generates the calibrated measurement value corresponding to each calibration point according to the stable signal; under the preset linear relationship, the data processing module determines the calibration coefficient according to the real-time measurement stability value and the calibrated measurement value of each calibration point, and uses the calibration coefficient to recalibrate the multimeter.

6. The multimeter according to claim 5, characterized in that: The data processing module calculates the standard deviation of each measurement group, and determines the fluctuation difference of each measurement group according to the standard deviation of each measurement group.

7. The multimeter according to claim 6, characterized in that: The data processing module determines the coefficient value representing the slope of the linear relationship and the offset value representing the intercept of the linear relationship according to the real-time measurement stability value and the calibration measurement value of each calibration point under the linear relationship.

8. The multimeter according to claim 5, characterized in that: In the calibration setting module, the difference between the calibration points is greater than a set threshold.

Images