CN114167113A - Sampling method and system for accurately determining bandwidth of integral digital multimeter - Google Patents
Sampling method and system for accurately determining bandwidth of integral digital multimeter Download PDFInfo
- Publication number
- CN114167113A CN114167113A CN202111678668.8A CN202111678668A CN114167113A CN 114167113 A CN114167113 A CN 114167113A CN 202111678668 A CN202111678668 A CN 202111678668A CN 114167113 A CN114167113 A CN 114167113A
- Authority
- CN
- China
- Prior art keywords
- frequency
- digital multimeter
- bandwidth
- sampling
- accurately determining
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000005070 sampling Methods 0.000 title claims abstract description 98
- 238000000034 method Methods 0.000 title claims abstract description 51
- 238000012360 testing method Methods 0.000 claims abstract description 18
- 238000005259 measurement Methods 0.000 claims description 18
- 238000004422 calculation algorithm Methods 0.000 claims description 12
- 238000004364 calculation method Methods 0.000 claims description 6
- 238000004891 communication Methods 0.000 claims description 5
- 238000011161 development Methods 0.000 claims 1
- 238000001514 detection method Methods 0.000 abstract description 3
- 230000010354 integration Effects 0.000 description 5
- 238000000691 measurement method Methods 0.000 description 4
- 238000013461 design Methods 0.000 description 3
- 230000002238 attenuated effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000009795 derivation Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000010365 information processing Effects 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 230000010363 phase shift Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
- G01R15/12—Circuits for multi-testers, i.e. multimeters, e.g. for measuring voltage, current, or impedance at will
- G01R15/125—Circuits for multi-testers, i.e. multimeters, e.g. for measuring voltage, current, or impedance at will for digital multimeters
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/25—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
- G01R19/2503—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques for measuring voltage only, e.g. digital volt meters (DVM's)
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Current Or Voltage (AREA)
Abstract
A sampling method for accurately determining the bandwidth of an integral digital multimeter, comprising: outputting a sinusoidal voltage input signal with adjustable frequency by a function signal generator, gradually changing the frequency of the input signal from low frequency to high frequency, and simultaneously keeping the amplitude of the output voltage of the function signal generator constant; when the sampling frequency meets the Nyquist sampling theorem, directly measuring the amplitude-frequency characteristic of the integral digital multimeter to obtain the bandwidth of the integral digital multimeter; and when the sampling frequency is less than twice the frequency of the measured signal, calculating the amplitude of the measured signal according to the sampling points by adopting a dispersive sampling method, and using a smaller frequency step value when the frequency is closer to the bandwidth frequency of the measured digital multimeter so as to reduce the uncertainty. The invention not only simplifies the testing equipment and the wiring scheme and improves the portability of the measuring system, but also has simple structure, convenient connection, low cost and good stability and meets the requirement of industrial detection.
Description
Technical Field
The invention relates to the technical field of metering of instruments and meters, in particular to a sampling method and a sampling system for accurately determining the bandwidth of an integral digital multimeter.
Background
The digital sampling technology is widely applied to various fields of measurement, control, communication, information processing and the like. Physical quantities in nature are analog quantities, so that analog signals need to be converted into digital quantities through analog-to-digital conversion (ADC) to be operated, stored and transmitted, thereby exerting powerful operation and processing functions of a computer. Various digital display type digital multimeters convert non-electric signals into electric quantity for measurement after conversion by a sensor. According to the working principle, the ADCs of such digital multimeters can be classified into a comparative type and an integral type. The current market widely uses a 3458A model 8.5 bit digital multimeter produced by the German technology company, namely, the voltage and current signals are measured by adopting a double-slope integration principle.
The basic operation principle of the dual-slope integrating ADC is that the measured voltage is first integrated for a certain time, and then the reference voltage with opposite polarity is reversely integrated by the same integrator until the output of the integrator returns to zero level. The time interval for this inverse integration is dependent on the measured voltage. Then, the time interval is digitally encoded by an electronic counter, and the measured voltage value can be obtained. The features of the double-slope integration are strong anti-interference ability, strong inhibition ability to AC series-mode signal with symmetrical amplitude, and completely eliminating symmetrical power frequency interference signal if the integration time is integral multiple of power frequency period. In addition, the requirements on the accuracy of an integral element and a clock signal are not high, and the measurement sensitivity can reach high gain. Such digital multimeters are available as laboratory standard instruments in the field of precision metrology. The input channel of the integral digital multi-purpose meter can be described by a first-order low-pass filter, and the input and output of the integral digital multi-purpose meter have attenuation coefficient eBP：
Where ω is the angular frequency of the measured signal and f is the measured signal frequency. When the frequency f of the measured signal is equal to f0The measurement result is attenuated by the bandwidth suppression of the digital multimeter to 0.707 times the amplitude of the input signal. And the phase lead angle due to bandwidth limitation is:
referring to fig. 5, fig. 5 is a graph illustrating a phase advance phenomenon caused by bandwidth limitation. When the integral digital multimeter is used for sampling the measured signal, the initial phase of the measured signal obtained by calculating through the sampling point is advanced by an angle, and the initial phase shift of the measured signal can be compensated if the bandwidth of the digital multimeter can be determined.
Unfortunately, most digital multimeters do not provide an indication of their bandwidth or only provide a range of their bandwidth, even if the bandwidth range is given, if its value is to be determined accurately, it is required that the sampling rate of the digital multimeter should be at least twice as high as its bandwidth, for example, 8.5-bit digital multimeters produced by de corporation specify that their bandwidth is not less than 150kHz in the dc voltage sampling mode, but the maximum sampling rate is only 100kps, which is far less than the minimum requirement of 300 kHz.
The bandwidth index is tested in the production and debugging stage of the instrument, and once the whole instrument is finished, the bandwidth of the digital multimeter is difficult to be accurately tested by a later amplitude-frequency measurement method. The existing measuring method still measures the amplitude-frequency characteristic of the digital multimeter at low frequency, and then deduces the frequency when the signal amplitude is attenuated to-3 dB through an input-output model of the system. This indirect measurement method causes a large uncertainty in the bandwidth derivation.
Disclosure of Invention
The first objective of the present invention is to provide a sampling method for accurately determining the bandwidth of an integral digital multimeter, in which most digital multimeters do not provide bandwidth indexes or only provide bandwidth ranges, even if bandwidth ranges are provided, if the numerical values of the digital multimeters are to be accurately determined, the sampling rate of the digital multimeter is required to be at least twice of the bandwidth, and the existing instruments are far from meeting the above requirements.
A second object of the present invention is to provide a system using the sampling method, in which most digital multimeters do not provide bandwidth indexes or only provide bandwidth ranges, even if bandwidth ranges are provided, if the numerical values are determined accurately, the sampling rate of the digital multimeter is required to be at least twice of the bandwidth, and the existing instruments are far from meeting the above requirements.
To achieve the object of the present invention, the present invention provides a sampling method for accurately determining bandwidth of an integral digital multimeter, the sampling method for accurately determining bandwidth of an integral digital multimeter, comprising:
step S11 is executed: outputting a sinusoidal voltage input signal with adjustable frequency by a function signal generator, gradually changing the frequency of the input signal from low frequency to high frequency, and simultaneously keeping the amplitude of the output voltage of the function signal generator constant;
step S12 is executed: when the sampling frequency meets the Nyquist sampling theorem, directly measuring the amplitude-frequency characteristic of the integral digital multimeter to obtain the bandwidth of the integral digital multimeter;
step S13 is executed: and when the sampling frequency is less than twice the frequency of the measured signal, calculating the amplitude of the measured signal according to the sampling points by adopting a dispersive sampling method, and using a smaller frequency step value when the frequency is closer to the bandwidth frequency of the measured digital multimeter so as to reduce the uncertainty.
Optionally, the distributed sampling method is to distribute the points that should be sampled within one period to the corresponding points after one period or multiple periods for sampling, so as to effectively reduce the requirement on the sampling rate.
Alternatively, the waveform remains stable during the down-sampling interval in actual measurement.
Optionally, the sampling process employs a modified quasi-synchronization algorithm.
To achieve the second objective of the present invention, the present invention provides a system of sampling method for accurately determining bandwidth of integral digital multi-purpose meter, the system for accurately determining bandwidth of integral digital multi-purpose meter comprising:
the PC is provided with a USB interface, and the PC is matched with software and an instrument consisting of a function signal generator and a digital multimeter to realize communication through the USB interface;
the function signal generator is electrically connected with the PC through the USB interface and inputs a sampling signal to the digital multimeter;
the digital multimeter is electrically connected with the PC through the USB interface and receives an input sampling signal of the function signal generator;
and the GPIB-USB converter is used for converting the instrument with the GPIB interface into the USB interface and then electrically and mechanically connecting with the PC.
Optionally, the PC accessory software communicates with the GPIB interface using a USB interface.
Optionally, the PC is developed by using MATLAB as a software, and the control program includes instrument parameter configuration, a test algorithm, a test record, a calculation amplitude value display, a frequency calculation, and an image display.
Optionally, the process flow of the system for accurately determining the bandwidth of the integral digital multimeter comprises:
step S21 is executed: starting a program;
step S22 is executed: judging whether the program is successfully connected, if so, continuing to perform the next step, otherwise, finishing, and checking whether the instrument connecting line is well connected;
step S23 is executed: starting testing and initializing the system;
step S24 is executed: judging whether the current test frequency needs to be down-sampled, if so, calculating the corresponding frequency of the digital multimeter, and if not, continuing the established flow;
step S25 is executed: configuring a digital multimeter, equipment parameters of the function signal generator, and controlling the function signal generator to output corresponding frequencies;
step S26 is executed: reading the data of the digital multimeter, calculating frequency difference and frequency by using an improved quasi-synchronous algorithm, and recording and displaying the frequency difference and the frequency on a graph;
step S27 is executed: and judging whether the sample is enough, if so, ending the process, and otherwise, returning to the step S24.
In conclusion, the system for accurately determining the bandwidth of the integral digital multimeter simplifies the testing equipment and the wiring scheme, improves the portability of the measuring system, gradually increases the frequency of an input signal from 50Hz, quantitatively describes the amplitude-frequency characteristic curve of a gear channel by software by utilizing an improved quasi-synchronous algorithm and a down-sampling rate method, thereby accurately determining the bandwidth, realizes configuration, processes and analyzes data by the software in the whole process, does not need an additional built-in module, has simple structure, convenient connection, low cost and good stability, and meets the requirement of industrial detection.
Drawings
FIG. 1 is a flow chart of a sampling method for accurately determining the bandwidth of an integral digital multimeter of the present invention;
FIG. 2 is a schematic diagram of the down-sampling rate measurement of the input bandwidth of a model 3458A digital multimeter from German corporation;
FIG. 3 is a flowchart of the process of the system for accurately determining the bandwidth of the integral digital multimeter of the present invention;
FIG. 4 is a graph showing the amplitude-frequency characteristics of two digital multimeters of the same model;
fig. 5 is a graph showing a phase advance phenomenon caused by bandwidth limitation.
Detailed Description
The invention will be described in detail with reference to the following embodiments and drawings for illustrating the technical content, structural features, and achieved objects and effects of the invention.
The sampling method for accurately determining the bandwidth of the integral digital multimeter is a sampling method for accurately determining the bandwidth of the digital multimeter under the conditions that no bandwidth index of the digital multimeter is given or only the bandwidth range is given, and the sampling rate of the digital multimeter cannot meet the Nyquist theorem (twice the bandwidth). Therefore, the phenomenon of phase lead of the sampling signal caused by bandwidth limitation can be compensated, and the initial phase of the measured signal can be accurately determined.
Referring to fig. 1, fig. 1 is a flow chart illustrating a sampling method for accurately determining the bandwidth of an integral digital multimeter according to the present invention. The sampling method for accurately determining the bandwidth of the integral digital multimeter comprises the following steps:
step S11 is executed: outputting a sinusoidal voltage input signal with adjustable frequency by a function signal generator, gradually changing the frequency of the input signal from low frequency to high frequency, and simultaneously keeping the amplitude of the output voltage of the function signal generator constant;
step S12 is executed: when the sampling frequency meets the Nyquist sampling theorem, directly measuring the amplitude-frequency characteristic of the integral digital multimeter to obtain the bandwidth of the integral digital multimeter;
step S13 is executed: and when the sampling frequency is less than twice the frequency of the measured signal, calculating the amplitude of the measured signal according to the sampling points by adopting a dispersive sampling method, and using a smaller frequency step value when the frequency is closer to the bandwidth frequency of the measured digital multimeter so as to reduce the uncertainty.
In order to describe the technical scheme of the present invention more intuitively and to highlight the beneficial effects of the present invention, the specific steps and the operation principle of the sampling method and the system for accurately determining the bandwidth of the integral digital multimeter are explained in conjunction with the specific embodiments. In the specific embodiment, the types of the function signal generator, the digital multimeter, the sampling parameter setting, and the like are only examples, and should not be construed as limiting the technical solution of the present invention. More specifically, the function signal generator is a 33250A function signal generator manufactured by German corporation. The digital multimeter is a model 3458A digital multimeter manufactured by Germany corporation.
Referring to fig. 2, fig. 2 is a schematic diagram illustrating the input bandwidth of a type 3458A digital multimeter from german corporation for downsampling measurement. In the digital multimeter of the model 3458A of the german corporation, in a direct-current voltage sampling mode, the bandwidth given in the specification is not less than 150kHz, so that if an actual value of the bandwidth is to be accurately measured, the sampling frequency should be not less than 300kps, and the maximum sampling rate in the mode is only 100kps, so that an accurate value of the bandwidth cannot be directly obtained by an amplitude-frequency measurement method.
Therefore, the invention provides a dispersive sampling method, which can indirectly obtain the bandwidth of the input channel. The working principle of the dispersive sampling method is as follows, the period of a signal to be detected is assumed to be T, S points are sampled in one period, and the sampling interval is T/S. Because the sampling frequency is limited, the sampling sequence is [ n ] under the assumption that the actual sampling frequency is f' and the sampling interval is T0,n1,n2···nS-1]Then, then
Get
Where k is 1,2,3, one of the solutions of this equation can be found as:
as those skilled in the art will readily understand, the distributed sampling method is to distribute the points that should be sampled in one period to the corresponding points after one or more periods for sampling, so as to effectively reduce the requirement for the sampling rate, and in the actual measurement, the waveform is required to be stable enough in the time interval of the sampling rate reduction.
Obviously, the sampling method for accurately determining the bandwidth of the integral digital multimeter can obtain the following beneficial effects that (1) the problem that the bandwidth of the digital multimeter cannot be directly measured through amplitude-frequency characteristics due to the limitation of the sampling frequency of the digital multimeter is solved. (2) The problem of measuring amplitude-frequency characteristics under low frequency, the bandwidth uncertainty that the indirect measurement method of fitting when high frequency causes is too big is solved. (3) The requirement on the accuracy of a signal source is not high during measurement, and the higher the frequency of an input signal is, the smaller the uncertainty of a bandwidth measurement result is. (4) The input signal frequency can be set to obtain the expected measurement uncertainty according to the measurement requirement of the bandwidth.
As a specific embodiment, for example, and without limitation, the adjustment is that a model 33622A function signal generator (bandwidth 120MHz) produced by Germany corporation outputs 2Vpp from 50Hz, the amplitude of the input signal is measured by a 1V range of a digital multimeter of Germany 3458A type, and the integration time is set to 3 μ s; the model 33250A function signal generator is used as a sampling signal input to the external trigger input of the model 3458A digital multimeter, 100 points are sampled every period, the sampling period is set to be 3.01 multiplied by T, and the frequency of the model 33622A function signal generator is output to the signal input of the model 33250A function signal generator, namely, the time base of the measured and sampled signals is simultaneously. The 2Vpp input signal is held constant with the 50Hz measurement as the normalized reference voltage value, looking for the input signal frequency when the measured attenuation is 0.707. Because the frequency of the clock signal cannot be infinitely subdivided, namely the set sampling interval may cause non-whole period sampling after sampling 100 points, the quasi-synchronization algorithm adopted in the sampling process can eliminate amplitude calculation errors caused by the non-whole period sampling.
Referring to fig. 3, fig. 3 is a flowchart illustrating a process of a system for accurately determining the bandwidth of an integral digital multimeter according to the present invention. The system for accurately determining the bandwidth of an integral digital multimeter comprises:
the PC is provided with a USB interface, and the PC is matched with software and an instrument consisting of a function signal generator and a digital multimeter to realize communication through the USB interface;
the function signal generator is electrically connected with the PC through the USB interface and inputs a sampling signal to the digital multimeter;
the digital multimeter is electrically connected with the PC through the USB interface and receives an input sampling signal of the function signal generator;
and the GPIB-USB converter is used for converting the instrument with the GPIB interface into the USB interface and then electrically and mechanically connecting with the PC.
As one skilled in the art will readily appreciate, the PC peripheral software may also communicate with the function signal generator using an Ethernet interface, and may also support RS232 in communication with the digital multimeter.
More specifically, the PC matching software adopts the design idea of a virtual instrument and is developed by applying MATLAB, and the control program comprises instrument parameter configuration, a test algorithm, test records, calculation amplitude value display, frequency calculation, image display and the like. The process flow of the system for accurately determining the bandwidth of the integral digital multimeter comprises the following steps:
step S21 is executed: starting a program;
step S22 is executed: judging whether the program is successfully connected, if so, continuing to perform the next step, otherwise, finishing, and checking whether the instrument connecting line is well connected;
step S23 is executed: starting testing and initializing the system;
step S24 is executed: judging whether the current test frequency needs to be down-sampled, if so, calculating the corresponding frequency of the digital multimeter, and if not, continuing the established flow;
step S25 is executed: configuring a digital multimeter, equipment parameters of the function signal generator, and controlling the function signal generator to output corresponding frequencies;
step S26 is executed: reading the data of the digital multimeter, calculating frequency difference and frequency by using an improved quasi-synchronization algorithm, recording and displaying in a graph;
step S27 is executed: and judging whether the sample is enough, if so, ending the process, and otherwise, returning to the step S24.
Referring to fig. 4, fig. 4 shows the amplitude-frequency characteristic curves of two digital multimeters of the same model. It will be readily appreciated that the functionality and performance of the system for accurately determining the bandwidth of an integral digital multimeter of the present invention includes the following aspects: (1) the system can accurately measure the bandwidth of the integral digital multimeter. (2) When the sampling frequency of the Nyquist frequency of the measured signal cannot be provided, the measurement is performed by using a specific down-sampling rate method. (3) The PC matching software of the device adopts a design method of a virtual instrument, the interface is provided with a parameter setting for configuring a digital multi-purpose table and a function signal generator, the amplitude and the frequency are calculated by an improved quasi-synchronous algorithm, and the displayed number is displayed. (4) And displaying the amplitude obtained by all the tested frequencies by using the amplitude-frequency characteristic curve. (5) The testing range channel can be flexibly configured according to the requirement, and whether to store and export the testing data and the testing result can be automatically determined after the sampling is finished. (6) The device can reach the specific value difference of 0.01 percent and the phase difference of 1' within the frequency range of 50Hz to 200 kHz.
Table: measurement of measured bandwidth
In summary, the system for accurately determining the bandwidth of the integral digital multimeter of the present invention comprises a 33250A type function signal generator, which is a 3458A type digital multimeter manufactured by germany corporation, a GPIB-USB converter, and a PC accessory software. When the method is used for accurately determining the bandwidth of the integral type digital multimeter, the gear of the required measurement bandwidth is determined, the software controls the 33250A type function signal generator to send an alternating current signal with proper amplitude, then the software reads data of the 3458A type digital multimeter of the German company through GPIB, processes and analyzes the data to obtain the amplitude of the measured signal, the frequency of the input signal is continuously changed through the software, and finally the actual bandwidth of the currently used gear of the 3458A type digital multimeter of the German company is determined according to the attenuation condition of the amplitude of the measured signal.
The gear bandwidth of the digital multimeter is only a typical value provided by a manufacturer for a specific model, and in order to obtain more accurate bandwidth compensation in the actual use of the digital multimeter, the measurement system provides a set of solution for accurately determining the plug-and-play bandwidth of any digital multimeter with the same model. The design simplifies the testing equipment and the wiring scheme, and improves the portability of the measuring system. After the connection of the equipment is checked to be normal, only the gear needing to determine the bandwidth needs to be selected in the software interface, and clicking is started. The system gradually increases the frequency of an input signal from 50Hz, quantitatively describes the amplitude-frequency characteristic curve of a gear channel by using an improved quasi-synchronization algorithm and a down-sampling rate method through software, so that the bandwidth is accurately determined, whether read data is stored or not can be selected according to the requirement, the configuration, the data processing and analysis are realized through the software in the whole process, an additional built-in module is not needed, the structure is simple, the connection is convenient, the cost is low, the stability is good, and the industrial detection requirement is met.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
Claims (8)
1. A sampling method for accurately determining the bandwidth of an integral digital multimeter, the sampling method for accurately determining the bandwidth of the integral digital multimeter comprising:
step S11 is executed: outputting a sinusoidal voltage input signal with adjustable frequency by a function signal generator, gradually changing the frequency of the input signal from low frequency to high frequency, and simultaneously keeping the amplitude of the output voltage of the function signal generator constant;
step S12 is executed: when the sampling frequency meets the Nyquist sampling theorem, directly measuring the amplitude-frequency characteristic of the integral digital multimeter to obtain the bandwidth of the integral digital multimeter;
step S13 is executed: and when the sampling frequency is less than twice the frequency of the measured signal, calculating the amplitude of the measured signal according to the sampling points by adopting a dispersive sampling method, and using a smaller frequency step value when the frequency is closer to the bandwidth frequency of the measured digital multimeter so as to reduce the uncertainty.
2. The sampling method for accurately determining the bandwidth of an integral digital multimeter of claim 1 wherein the scatter sampling method is to scatter the points that should have been sampled within one period to the corresponding points after one or more periods for sampling, thereby effectively reducing the sampling rate requirements.
3. The sampling method for accurately determining the bandwidth of an integral digital multimeter of claim 1 wherein the actual measurement is performed with the waveform stable for a time interval of the down-sampling rate.
4. The sampling method for accurately determining the bandwidth of an integral digital multimeter of claim 1 wherein the sampling process employs a modified plesiochronous algorithm.
5. A system for a sampling method for accurately determining the bandwidth of an integral digital multimeter as recited in claim 1, wherein said system for accurately determining the bandwidth of an integral digital multimeter comprises:
the PC is provided with a USB interface, and the PC is matched with software and an instrument consisting of a function signal generator and a digital multimeter to realize communication through the USB interface;
the function signal generator is electrically connected with the PC through the USB interface and inputs a sampling signal to the digital multimeter;
the digital multimeter is electrically connected with the PC through the USB interface and receives an input sampling signal of the function signal generator;
and the GPIB-USB converter is used for converting the instrument with the GPIB interface into the USB interface and then electrically and mechanically connecting with the PC.
6. The system for accurately determining the bandwidth of an integrating digital multimeter of claim 5 wherein said PC accessory software communicates with the function signal generator GPIB interface via a USB interface.
7. The system for accurately determining bandwidth of an integral digital multimeter of claim 5 wherein said PC is configured with software application MATLAB for development, the control program comprising instrument parameter configuration, test algorithms, test logs, calculated amplitude value display, frequency calculation, and image display.
8. The system for accurately determining the bandwidth of an integral digital multimeter of claim 5 wherein the program flow of the system for accurately determining the bandwidth of an integral digital multimeter comprises:
step S21 is executed: starting a program;
step S22 is executed: judging whether the program is successfully connected, if so, continuing to perform the next step, otherwise, finishing, and checking whether the instrument connecting line is well connected;
step S23 is executed: starting testing and initializing the system;
step S24 is executed: judging whether the current test frequency needs to be down-sampled, if so, calculating the corresponding frequency of the digital multimeter, and if not, continuing the established flow;
step S25 is executed: configuring a digital multimeter, equipment parameters of the function signal generator, and controlling the function signal generator to output corresponding frequencies;
step S26 is executed: reading the data of the digital multimeter, calculating frequency difference and frequency by using an improved quasi-synchronization algorithm, recording and displaying in a graph;
step S27 is executed: and judging whether the sample is enough, if so, ending the process, and otherwise, returning to the step S24.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111678668.8A CN114167113B (en) | 2021-12-31 | 2021-12-31 | Sampling method and system for accurately determining bandwidth of integral digital multimeter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111678668.8A CN114167113B (en) | 2021-12-31 | 2021-12-31 | Sampling method and system for accurately determining bandwidth of integral digital multimeter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114167113A true CN114167113A (en) | 2022-03-11 |
| CN114167113B CN114167113B (en) | 2024-05-17 |
Family
ID=80488917
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111678668.8A Active CN114167113B (en) | 2021-12-31 | 2021-12-31 | Sampling method and system for accurately determining bandwidth of integral digital multimeter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114167113B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0983596A (en) * | 1995-09-14 | 1997-03-28 | Matsushita Electric Ind Co Ltd | Digital quadrature detector |
| US5793801A (en) * | 1996-07-09 | 1998-08-11 | Telefonaktiebolaget Lm Ericsson | Frequency domain signal reconstruction compensating for phase adjustments to a sampling signal |
| US5978742A (en) * | 1997-04-04 | 1999-11-02 | Tektronix, Inc. | Method and apparatus for digital sampling of electrical waveforms |
| CN1625064A (en) * | 2003-12-05 | 2005-06-08 | 皇家飞利浦电子股份有限公司 | Band pass sampling receiver and its sampling method |
| CN102981048A (en) * | 2011-09-06 | 2013-03-20 | 北京邮电大学 | Optical-sampling-based radio frequency measuring method and measuring device |
| CN103457606A (en) * | 2012-05-30 | 2013-12-18 | 英飞凌科技奥地利有限公司 | Method and device for sampling an input signal |
| CN104065608A (en) * | 2014-06-03 | 2014-09-24 | 北京创毅视讯科技有限公司 | Data processing method for communication equipment, and communication equipment |
| US20150280943A1 (en) * | 2012-10-23 | 2015-10-01 | Yushan Hao | Data Sampling Method and System, and Application Method and System Thereof in Parameter Identification |
| CN105763225A (en) * | 2016-04-25 | 2016-07-13 | 山东大学 | Generation method of sparse dictionary of pulse ultra wide band signal |
| CN107147427A (en) * | 2016-03-01 | 2017-09-08 | 中兴通讯股份有限公司 | A kind of method of sampling of signal, device and system |
-
2021
- 2021-12-31 CN CN202111678668.8A patent/CN114167113B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0983596A (en) * | 1995-09-14 | 1997-03-28 | Matsushita Electric Ind Co Ltd | Digital quadrature detector |
| US5793801A (en) * | 1996-07-09 | 1998-08-11 | Telefonaktiebolaget Lm Ericsson | Frequency domain signal reconstruction compensating for phase adjustments to a sampling signal |
| US5978742A (en) * | 1997-04-04 | 1999-11-02 | Tektronix, Inc. | Method and apparatus for digital sampling of electrical waveforms |
| CN1625064A (en) * | 2003-12-05 | 2005-06-08 | 皇家飞利浦电子股份有限公司 | Band pass sampling receiver and its sampling method |
| CN102981048A (en) * | 2011-09-06 | 2013-03-20 | 北京邮电大学 | Optical-sampling-based radio frequency measuring method and measuring device |
| CN103457606A (en) * | 2012-05-30 | 2013-12-18 | 英飞凌科技奥地利有限公司 | Method and device for sampling an input signal |
| US20150280943A1 (en) * | 2012-10-23 | 2015-10-01 | Yushan Hao | Data Sampling Method and System, and Application Method and System Thereof in Parameter Identification |
| CN104065608A (en) * | 2014-06-03 | 2014-09-24 | 北京创毅视讯科技有限公司 | Data processing method for communication equipment, and communication equipment |
| CN107147427A (en) * | 2016-03-01 | 2017-09-08 | 中兴通讯股份有限公司 | A kind of method of sampling of signal, device and system |
| CN105763225A (en) * | 2016-04-25 | 2016-07-13 | 山东大学 | Generation method of sparse dictionary of pulse ultra wide band signal |
Non-Patent Citations (4)
| Title |
|---|
| 孟卓: "改进准同步采样电力系统频率测量方法及应用研究", 中国优秀硕士学位论文全文数据库工程科技Ⅱ辑, no. 03, 15 March 2017 (2017-03-15), pages 8 - 12 * |
| 潘洋 等: "一种新型低值宽带无感分流器时间常数测量方法", 计量学报, vol. 40, no. 06, 22 November 2019 (2019-11-22), pages 946 - 951 * |
| 潘洋 等: "基于采样逼近的准同步改进算法研究", 仪器仪表学报, vol. 37, no. 03, 15 March 2016 (2016-03-15), pages 512 - 517 * |
| 马也驰 等: "应用于频率宽范围偏移电网的改进相位差校正法", 电力系统自动化, vol. 41, no. 23, 10 December 2017 (2017-12-10), pages 130 - 136 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114167113B (en) | 2024-05-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1454317A (en) | Electronic power meter with phase and non-linearity compensation | |
| US11262429B2 (en) | Method, apparatus and device for detecting abnormity of energy metering chip, and medium | |
| CN218272637U (en) | Contact checking circuit for battery internal resistance tester and battery internal resistance tester | |
| CN108196217B (en) | Direct current metering method and system for off-board charger current calibration instrument | |
| Hoja et al. | Portable analyzer for impedance spectroscopy | |
| Petrovic | New digital multimeter for accurate measurement of synchronously sampled AC signals | |
| US20070226602A1 (en) | Measuring device and method for measuring relative phase shifts of digital signals | |
| CN103575976B (en) | A kind of pure 90 degree of phase shift reactive power measuring methods | |
| CN114167113B (en) | Sampling method and system for accurately determining bandwidth of integral digital multimeter | |
| EP0862060A2 (en) | RMS converter using digital filtering | |
| EP0916956A1 (en) | RMS converter for obtaining fast RMS measurements | |
| Caldara et al. | Measurement uncertainty estimation of a virtual instrument | |
| CN109596694B (en) | Measurement and analysis device suitable for different impedance electrochemical systems | |
| CN101329215A (en) | Output measuring circuit and measuring method of capacitance differential pressure transducer | |
| US20100106763A1 (en) | RMS Metering Devices and Methods | |
| CN112666485B (en) | Power stability analysis device and power system | |
| US6469492B1 (en) | Precision RMS measurement | |
| CN103575975A (en) | Constant-90-degree phase shift type reactive power measurement circuit | |
| CN109782057B (en) | Circuit and method for measuring input active power of single-phase power supply of variable-frequency household appliance | |
| CA3163927A1 (en) | Gating energy consumption accumulation by detecting a fundamental component of a current | |
| CN217278623U (en) | Line load network detection and fault positioning device | |
| JP3085496B2 (en) | Sampling type measuring device | |
| CN219349111U (en) | Ultra-low error high-precision measurement system for dual-channel voltage signal source | |
| RU82051U1 (en) | ONBOARD DISPERSION CALCULATOR | |
| Jenq | Discrete-time method for signal-to-noise power ratio measurement |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |