Abstract: This paper presents and discusses a low-cost and simple technique of monitoring and processing I-V and P-V curve of photovoltaic module. This curve is to be traced using Laboratory Virtual Instrument Engineering Workbench (LabVIEW) interface capability. The constructed LabVIEW software displays the electrical variables (voltage, current and power) on dedicated graph windows in a real time manner. The current versus voltage (I-V) and power versus voltage (P-V) characteristics are taken for any chosen panel, displayed and stored accurately. The proposed technique holds extra function of a digital multimeter (DMM) interfacing it with LabVIEW and its integration in to an application type of data acquisition and processing. User has possibility to observe and record data in the form of chart, table and file (.lvm) in real time. This whole system consists of personal computer with LabVIEW software, two DMMs, solar module, a variable resistive load. This paper can also be discussed further research plan in the area of load analysis of PV system.

Abstract: The invention relates to a cloud service mode-based remote verification system of a digital multimeter. A remote server end gives out and transports transmission standards to a client end. A standard device is connected with a to-be-verified meter via a multi-way switch, thereby facilitating channel switching of all detection items. A mobile terminal supporting NFC is used for reading to-be-verified meter information and verification records of NFC electronic tags on the to-be-verified meter. A verification software front panel sends the to-be-verified meter information and the verification records to the remote server end via network, thereby achieving real-time interaction of data. After the verification is finished, a cloud database for storing the verification records and the verification data is established on a cloud end via a cloud server, thereby facilitating record searching and data sharing. The mobile terminal is used for reading in the verification records of the NFC electronic tags of the to-be-verified meter so as to easily verify reading of information of the to-be-verified meter next time. Compared with a manual verification mode of a traditional digital multimeter, verification efficiency is greatly increased and errors caused by manual factors are reduced.

Abstract: This paper describes a method for the characterization of the amplitude frequency response of Analog-to-Digital converters at frequencies up to 20 kHz using a true quantum reference calibrated semiconductor based DAC arbitrary waveform generator, developed within the EMPIR project Q-WAVE, jointly founded by the European Union and the participating countries. The procedure that can be used for the characterization of any ADC is applied to the DCV function of a Keysight 3458A digital multimeter. The measurement conditions and the main uncertainty sources are identified and evaluated for complete uncertainty estimation by means of the Monte Carlo Method.

Abstract: This paper presents a data acquisition system to automate microcontroller energy consumption measurements. Taking a single measurement with a multimeter does not require much, but taking thousands of measurements per second will result in large amount of data that needs to be thoughtfully stored. The aim of the measurement system is to gather current consumption and pin toggle from microcontroller while executing different software programs. The data collection is handled via LabVIEW System Design Software. The measuring devices are connected to the host system by local area network and thus making them accessible from anywhere in the lab. The measurement equipment consists of power source, multimeter and oscilloscope which are all setup and controlled in LabVIEW. The gathered data is saved into TDMS file which is analysed during post-processing.

Abstract: The invention discloses a digital multimeter non-linear error compensation method which comprises the following steps: a range of reference values input by an amplifier input end is divided into five sections, the number of segments of the sections is set according to a ratio between non-linear absolute error in the sections and non-linear absolute error allowed in the sections, and each section is evenly segmented according to the number of segments; for each segment, a number of groups of data is obtained; each group of data comprises a reference value and a corresponding measured value, reference values of two groups of data are positioned at end points of a segment, a measured value range corresponding to the segment is obtained according to corresponding measured values, each segment is subjected to polynomial fitting operation according to fitting data, a polynomial formula is therefore obtained, a corresponding polynomial formula is chosen according to the measured value range corresponding to the measured values during actual measurement processes, and a corrected value is obtained via calculation. Via the digital multimeter non-linear error compensation method, non-linear error caused by an amplifier and an ADC in a digital multimeter can be compensated, and linear performance of the digital multimeter can be improved.

Abstract: Virtual Instrument is a combination of hardware and software that allows the emulation of an instrument through a custom virtual console and a graphical user interface. A virtual instrument consists of a PC equipped with powerful application software, cost-effective hardware such as plug-in boards, which together perform the functions of traditional instruments. In a virtual instrument, it is the software which performs the actual process of measurement. Using virtual instruments one can design a customized instrument and automation setup that is user-defined instead of being limited by traditional fixed-function vendor-defined instruments. Virtual instruments are not efficient systems to handle time critical instrument tasks since they are run by a PC operating system which introduced substantial timing errors into the measurement. The Reconfigurable Virtual Instrument (RVI) system can be considered as a general purpose measurement instrument designed with reconfigurable hardware like FPGA connected to PC through a standard port. By designing a high level software application, one can select any specific instrument functionality from a library of instruments. The high level software application configures the RVI system to convert it into the selected instrument(s) with its associated console. By this technique, one can emulate multiple instrument functionalities like function generator, oscilloscope, multimeter, logic analyzer in a single hardware platform. In this paper, hardware realization of RVI is done using FPGA and Raspberry Pi core.

Abstract: The invention discloses an artificial neural network algorithm-based battery management system and method. The artificial neural network algorithm-based battery management system comprises a program-controlled conversion and balance circuit, a direct-current programmable power supply, an electronic load, a temperature detection circuit, a digital multimeter and an upper computer. The artificial neural network algorithm-based battery management system is characterized in that the direct-current programmable power supply, the electronic load and the digital multimeter are all subjected to remote programming control by the upper computer; the direct-current programmable power supply, the electronic load and the digital multimeter are connected with a battery pack through a first relay, a second relay and a third relay respectively; the direct-current programmable power supply is used for charging the battery pack and detecting a charging current to output to the upper computer; and the electronic load is used for carrying out a discharging test on the battery pack, detecting a discharging current of the battery pack and outputting the discharging current to the upper computer. By an artificial neural network algorithm, the mapping rule of the electric quantity of the battery pack and dynamic parameters of the battery pack is obtained; accurate monitoring of the state of the battery pack is achieved; and the artificial neural network algorithm-based battery management system and method can be widely applied to the battery management system.

Abstract: The invention discloses an intelligentized curtain radio-frequency control module measuring device. A pneumatic current and voltage detecting unit, a radio-frequency signal detecting unit and a digital multimeter are respectively connected with a to-be-tested product and a testing computer, the IO port of a data acquisition module is in controlling connection with the to-be-tested product and a signal attenuation and conditioning module, the AI port of the data acquisition module is connected with the to-be-tested product through the signal attenuation and conditioning module, the radio-frequency power signal end of the to-be-tested product is connected to a spectrum analyzer through a radio-frequency line, and the spectrum analyzer and the data acquisition module are both in transmitting connection with the testing computer. Current and voltage signal control points on the to-be-tested product are led to the signal attenuation and conditioning module to properly attenuate to-be-measured signals, analog signals are measured after the AI channel of the data acquisition module controls on and off, the AI port acquires analog signals, and the IO port controls the state of the to-be-tested product, on and off of a power supply, static voltage and current and voltage and current in working. The radio-frequency signals are connected to the spectrum analyzer for sampling analysis.

Abstract: This paper describes a calibration system based on digital sampling of the reference synchronized to the pulse-per-second (PPS) signal of the merge unit (MU) for electronic transformer (ECT/EVT) under test. This calibration system is designed in conformity to the IEC61850-9-2LE standard for digital substation. The reference system included a two-stage CT up to 10 kA, a non-inductance shunt, reference VTs up to 220 kV/V3, an inductive voltage divider (IVD), a sampling voltage multimeter (DVM), a function generator(FG), a fiber-Ethernet converter and a clock synchronization device. Software for instrument control, packets capturing and a compensated discrete Fourier transform (DFT) algorithm were developed for the system. Uncertainty evaluation proved that this reference system is qualified for calibrating electronic transformers (ETs) with an accuracy class of 0.1S/0.1.

Abstract: The utility model relates to a RVDT angle displacement sensor test system, including observing and controling computer, alternating voltage source, digital display revolving stage and digital multimeter, the RVDT angle displacement sensor that awaits measuring fixes on the digital display revolving stage, the alternating voltage source is through 232 buses and observing and controlling computer link, the alternating voltage source supplies power to the RVDT angle displacement sensor that awaits measuring, and the RVDT angle displacement sensor's that awaits measuring output is connected with digital multimeter as the AD698 measurement station, the output and the observing and controlling computer link of digital display revolving stage, digital multimeter's output passes through the GPIB cable and observes and controls the computer link. For the technical problem who solves the unable quantitative measurement of angle displacement sensor, the utility model discloses the qualitative analysis means that always adopt before replacing can quantitative analysis, the accuracy acquires angle and sensor output voltage, the three measurement station output voltage's of signal conditioning circuit relation.

Abstract: The present invention provides a system of automatic measurement of a digital multimeter The system comprises a computer, a multifunctional calibrator connected with the computer, a manipulator controlled by the computer and configured to regulate the gears of the digital multimeter, a camera configured to shoot the display of the digital multimeter and transmit the shooting information to the computer, a printer connected with the USB of the computer, an order controller and a control module in the computer The order controller includes order control boxes and wiring control boxes, the order control boxes are connected between the multifunctional calibrator and the wiring control boxes, and the wiring control boxes are connected with the digital multimeter in a one-to-one correspondence relationship The system and method of automatic measurement of a digital multimeter are able to realize one-button start and perform repeat measurement detection of a plurality of insulation ohmmeters in different models through just one time setting, and the one-button completion from start to end is realized, therefore the high efficiency, the standardization, the informatization and the automation of the measurement work may be achieved

Abstract: The utility model provides an equip electric parameter calibrating installation. Be equipped with the panel in front at the casing, be equipped with DC voltage current output in proper order on the panel, alternating voltage current output, the output of three -phase alternating voltage, resistance output, waveform generator output, digital oscilloscope, the IO trigger control, digital multimeter, adapter control, power supply inputs, USB interface, display and control button. Device and examination circuit be equipped with in the casing. The utility model has the advantages of the accurate examination of portable and electric parameter, it is suitable applied as equip electric parameter calibrating installation.

Abstract: The invention relates to a comprehensive tester metering detection system, an adapter, and a metering test platform. The comprehensive tester metering detection system comprises the adapter and the metering test platform, the metering test platform is connected with the adapter and connected with a comprehensive tester via the adapter, the metering test platform comprises a digital multimeter, an oscilloscope, a function generator, a direct current voltage-stabilizing power supply, and an acquisition control device, the acquisition control device is used for acquiring output signals of the digital multimeter and the oscilloscope and controlling the output of the function generator and the direct current voltage-stabilizing power supply, the adapter comprises test interfaces used for being connected with the digital multimeter, the oscilloscope, the function generator, and the direct current voltage-stabilizing power supply of the metering test platform and adaptive interfaces used for being connected with corresponding terminals of the comprehensive tester, and a detection circuit corresponding to set detection items is formed between the test interfaces and the adaptive interfaces. The test object is the whole machine of the comprehensive tester rather than internal standard equipment, the conditions of various parameter indexes of the tested object are truly reflected, and the test precision is improved.

Abstract: The Karlsruhe Institute of Technology (KIT) has developed a new thermal method for flow measurement, which is particularly suitable for the application in cryogenic systems. In this method, the stability and the resolution of temperature measurement is important, rather than precision. In other words, constant offsets in temperature measurements can be ignored, and the temperature sensors can be operated at supply currents beyond their nominal design value in order to gain resolution. For this application, the performance of two Cernox TM type CX-1050-SD-HT-1.4L sensors was measured in a temperature range between 300 K and 4 K. The experiments were carried out in the calibration cryostat at the Institute for Technical Physics. Sensors were connected to a Lake Shore Model 121 current source and a Keithley 2701/E digital multimeter for voltage measurements. At constant calibration temperatures, the supply currents were varied such that the resulting voltage drops lay in-between 10 mV and 100 mV. The influence on both the noise and the temperature offset are presented.

Abstract: The invention provides a power conversion efficiency test device, a power conversion efficiency test method and a power conversion efficiency test system. The test device is connected with a target power source, an electronic load instrument and two multimeters, and comprises an adjusting unit, a receiving unit and a conversion efficiency calculating unit, wherein the adjusting unit is used for adjusting the electronic load instrument to a target load and triggering the receiving unit, the receiving unit is used for receiving a first input voltage value of the target power source sent by a first multimeter and a first output voltage value of the target power source sent by a second multimeter and receiving a first input current and a first output current sent by the target power source when triggered by the adjusting unit, and the conversion efficiency calculating unit is used for calculating the conversion efficiency of the target power source according to the first input voltage value, the first output voltage value, the first input current and the first output current received by the receiving unit. Through the scheme, automatic power conversion efficiency test is realized.

Abstract: The invention relates to a program-controlled multi-channel variable resistor and a resistance value adjustment and control method thereof. The variable resistor comprises a communication interface, a multi-channel resistance output interface, a single-chip microcomputer and at least one single channel, wherein the communication interface is connected with an upper computer of a control system, each single channel comprises a digital potentiometer and an electro-static discharge protection chip which form a series branch, communication is carried out between the single-chip microcomputer and a serial port conversion module by a universal asynchronous receiver/transmitter (UART) three-wire interface mode, the single-chip microcomputer and the digital potentiometers are arranged through an I C communication mode, or the tap position or the resistance value of the current digital potentiometer are read. The adjustment and control method comprises the following steps of 1) testing a serial port; 2) carrying out direct program-controlled reading and adjustment on the resistance value of the digital potentiometer of an appointed channel; and 3) periodically calibrating the resistance value of the digital potentiometer of each channel by a multimeter. The program-controlled multi-channel variable resistor and the resistance value adjustment and control method thereof have the advantages of simplicity in composition, convenience in use and accurate and reliable resistance value, the embedded software of the single-chip microcomputer can use the resistance value correction linear coefficient of each channel to automatically correct the resistance value, and the accuracy of the resistance value of the variable resistor is guaranteed.

Abstract: The invention discloses an intelligent multimedia interactive teaching and assessment system and method. The system comprises an engine teaching platform, a server and an intelligent terminal, wherein the engine teaching platform comprises a measuring unit and a control unit, the engine teaching platform transmits parameter data of an engine to the server, the server is used for transmitting the parameter data to the intelligent terminal, the intelligent terminal receives the parameter data and sends information to the server, the intelligent terminal is provided with a 3D engine model, the 3D engine model contains all circuits of the engine, the intelligent terminal is also provided with a virtual multimeter, and the virtual multimeter is used for displaying the parameter data of the engine. According to the invention, the intelligent terminal generates a 3D engine model, and links the circuits on the 3D engine model and corresponding parameter data together, and the parameter data of the circuits of the 3D engine model can be displayed by using the virtual multimeter, so that the teaching efficiency is improved.

Abstract: Traceability for AC currents below 1 mA is needed to calibrate calibrators and multimeters at frequencies up to at least 100 kHz. Since the sensitivity of thermal convertors is not sufficient, only transfer standards using amplifiers are suitable. A newly designed combination of an amplifier and a shunt works at higher frequencies up to 1 MHz as well.

Abstract: Measurement of electrical parameters like current and voltage are crucial in field of measurement. Frequency indicate the state of rhythmic behavior of signal and proper change in system with respect to time. Multimeter are used in measuring various electrical parameters including resistance, capacitance and inductance. This paper shed lights on the development of a low cost Multimeter using digital electronic circuitry. The proposed device is able to measure various electrical parameter in the certain specified range. A simple, but highly accurate, sampling method for the measurement of frequency in combination of other parameters are corporate here by means of a digital multimeter(DMM). In modern electronics laboratory a digital multimeter with high precision and digital displaying mechanism is an essential device. This paper describes the mechanism of a digital multimeter that can measure electrical parameters in under the particular range with specified resolution. accuracy of digital multimeter discussed in this paper is quite good, it can be used where precise measurement at low cost is required.

Abstract: The utility model relates to a comprehensive tester metrological verification system and adapter and measurement test platform, including adapter and measurement test platform, measurement test platform connects the adapter, connects comprehensive tester through the adapter, measurement test platform includes digital multimeter, oscillograph, function generator, D. C. Regulated power supply and acquisition control device, the acquisition control device is used for gathering the output signal of digital multimeter, oscillograph to control function generator, D. C. Regulated power supply's output, the adapter is including being used for the connection digital multimeter, oscillograph, function generator, D. C. Regulated power supply's test interface among the measurement test platform, and be used for connecting the adaptation interface that comprehensive tester corresponds the terminal, constitute between test interface and the adaptation interface and examination circuit that the examination project of settlement corresponds. Test object is the comprehensive tester complete machine but not inside standard device, has more truly reflected each parameter index's of measurand situation, has improved the measuring accuracy.

Abstract: The utility model discloses a novel digital power frequency virtual value multimeter of low -power consumption, including multimeter casing and internal circuit. The upper portion of multimeter casing front panel is equipped with the display screen, and the middle part is equipped with solar cell panel, and the lower part is equipped with the pen -shape metre jack that is used for gathering voltage signal, current signal. The internal circuit includes voltage changer, current transformation ware and microprocessor, voltage changer and current transformation ware and pen -shape metre jack connection, and voltage changer and current transformation ware are through handling circuit connection microprocessor, and microprocessor is through showing the circuit connection display screen. The great simplification of novel digital power frequency virtual value multimeter of low -power consumption circuit design for this multimeter has small convenient to carry, advantage that the operating procedure is simple, but wide application in fields such as scientific research, teaching experiment, instrument and meter measurement, domestic appliance maintenance, outdoor circuit maintenance.

Abstract: The Power monitoring system has been constructed using ACS 712 as a current sensor and step down transformer as avoltage sensor which coordinated by ATMega8535 and PC. Sensors output was processed by Microcontroller into ADC value and then it was sent into PC. In PC the ADC value was estimated into load voltage and load current value using interpolation equation written in VB.6.The interpolation equation was obtained through data analysis of load voltage and load current and ADC value of current and voltage sensors which was measured manually using digital multimeter. It was observed that load voltage and current estimation using quadratic interpolation gives a higher accuracy compare with linier and third order interpolation and achieved the percentage error in the order of 1%. The result estimated power value is displayed in PC monitor in line graph and database presentation at a certain time interval.

Abstract: In this paper we propose an application that adds extra functions of the bench multimeter MS8050 by connecting it to a computer and its integration into an application type of data acquisition and processing. This application provides user, by comparison with Bench Multimeter software, additional and complete features regarding collect, process and store data. The user has access via the front panel, to the modes of operation of the multimeter also to the data obtained from it, and can set the mode of representation of these data. User can select the data registration into a file for a further processing.

Abstract: The utility model discloses a liquid crystal display control assembly test system, including the computer, characterized by: the computer passes through the USB cable junction testboard, the testboard passes through test cable and connects liquid crystal display control assembly, digital multimeter able to programme and oscilloscope are still connected to the testboard. The utility model discloses a computer passes through the USB interface and is connected with the testboard to control whole test procedure, digital multimeter able to programme can be completely treats according to the test program that CMM provided and repaiies the piece and carry out complete functional test, and the testboard adopts high accuracy FPAG chip control relay unit able to programme, can the response test instruction of accurate high -efficient ground, improved efficiency of software testing and accuracy.

Abstract: From enriching VIIS-EW independently researched and developed by Jilin University, the development of virtual digital multimeter was finished for the purpose of designing modern intelligent digital multimeter. With the idea of modularization, the virtual digital multimeter was designed for the module with 3U card size, and the communication between controller was achieved using dual port RAM produced by FPGA. The main measuring circuit was composed of intelligent digital multimeter integrated circuit, to achieve the purpose of getting high performance objective through simple way. The instrument driver was designed by the form of the dynamic link library, and the I/O operations related with instrument were all encapsulated into function for the calling of application program. With the instrument operations the application calls for. The application program is developed by LabVIEW, and the communication with controller was realized through the CLF node. The Designed virtual digital multimeter did not only possess the basic measurement functions of traditional digital multimeter, but also had the advantages of data analysis, storage, report, network communication and so on, therefore, it can be applied to electrical and electronic measurements and other related fields.

Abstract: The calibration of electronic transformer (ET) with digital output can be realized using reference digital voltage multimeter(DVM)with synchronized sampling. However, there are time related errors of DVM which affect the result of phase displacement of ET under calibration. Such errors include the trigger latency, bandwidth limitation and aperture time of the DVM. This paper estimates the errors and makes a correction to the calibration result. The accuracy of the correction is verified using an arbitrary waveform generator (AWG) with dual synchronized channels with satisfactory results.

Abstract: The invention discloses a test device for low resistance conduction The test device is used for conduction tests of low resistance The test device is characterized in that the test device includes a battery power supply system, a voltage dividing circuit, a voltage follower, a voltage comparator, a bridge circuit and a buzzer; the output end of the battery power supply system is connected with the inputs end of the voltage dividing circuit, the voltage follower and the bridge circuit; the input end of the voltage follower is connected with output end of the voltage dividing circuit; the input end of the bridge is connected with the output end of the voltage follower; the input end of the voltage comparator is connected with the output end of the bridge; and the output end of the buzzer is connected with the input end of the voltage comparator The test device of the invention is mainly used for conduction tests of printed wires and cables With the device adopted, false alarm faults caused by large maximum on resistance of a multimeter can be eliminated, and the reliability of conduction detection can be improved The test device has the advantages of portable convenience and convenience in battery replacement

Abstract: An automated test bench for the study of the characteristics of various kinds of chips of mobile sources of regulated charge pump secondary power supply receiving energy from batteries was created. Having a modular structure, the test bench includes, in addition to the test charge pump module, power supply, control, load, display modules, and a USB module for connection with a computer. The test bench enables carrying out research of various types of chips by changing only one small measuring board. The control module is based on PIC18F2550 microcontroller. The automated measuring system consists of a multimeter and oscilloscope. The investigated characteristics are output voltage as a function of load current, output voltage as a function of supply voltage, the forms of the output voltage ripple, the response of chips to a stepped load transition. One of the major goals of the research is to study algorithms of the charge pump circuits. A program for controlling the test bench by creating a virtual front panel was developed. Together with a virtual panel of the oscilloscope and available multimeter software this allows controlling the equipment operating parameters and making measurements remotely over the Internet. Using the created test bench new experimental data on all of the above characteristics for MAX1759 chip were obtained, and an algorithm of this chip in the buck mode operation was studied for the first time.