636 results about "Multimeter" patented technology

The invention relates to an anti-electricity-stealing monitoring method and device based on an intelligent universal meter, equipment and a medium. The method comprises the following steps: acquiring real-time electric sampling data of a universal meter, and preprocessing the data to obtain electric characteristic data; carrying out electricity stealing feature extraction on the electricity feature data by utilizing an edge electricity stealing detection model, and carrying out preliminary judgment on an electricity utilization type to obtain a preliminary judgment result; if the preliminary judgment result is at least one of an electricity larceny event and reverse feed, using a cloud electricity larceny detection model to perform secondary analysis on the electricity characteristic data to obtain an abnormal probability; and if the abnormal probability exceeds a preset threshold, generating a corresponding alarm work order, and pushing the alarm work order to a supervision platform. By adopting the method, the field acquisition capability of the intelligent multimeter can be fully combined, the local and cloud computing characteristics are combined, and the recognition and monitoring of electricity stealing behaviors such as low-current electricity stealing and reverse feed are effectively enhanced through a multi-source feature extraction and judgment mechanism.

The invention discloses a computer power-on detection device, and belongs to the technical field of computer detection, the computer power-on detection device comprises a rack, a conveyor belt is fixedly mounted on the rack, a righting assembly and a detection assembly are arranged above the conveyor belt, the detection assembly comprises a multimeter and a contact piece, the back surface of the rack is fixedly connected with a support frame and a support plate, and the support plate is fixedly connected with the support frame. The centralizing assembly moves up and down along the supporting frame, an electric push rod is fixedly connected to the top of the supporting plate, the output end of the electric push rod is fixedly connected with a universal meter, and a probe of the universal meter is fixedly connected with a contact piece. According to the technical scheme, accurate butt joint of the detection assembly and the computer is guaranteed, the detection assembly can conduct continuous detection operation on a plurality of righting computer materials, the continuity of detection work is effectively improved, and therefore the technical effect of improving the detection precision and the detection work efficiency is facilitated.

The invention relates to the technical field of diode detection, in particular to a vehicle gauge level diode detection method, which comprises the following steps of: acquiring a plurality of pieces of image information of each view of a diode to construct a spatial model of the diode, and determining the qualification of the spatial form of diode packaging based on the overall fitting degree of the spatial model. And determining the diode packaging qualification based on the straight line contact ratio of the pins. Carrying out preliminary detection by using a universal meter based on the packaged qualified diode, and determining the minimum dynamic resistance based on the volt-ampere characteristic curve of the diode under the condition that the access is qualified so as to carry out preliminary grading on the performance of the diode; and the detection voltage is matched based on the preliminary grading result, the temperature of the diode is monitored in real time in the detection process to establish a temperature fluctuation curve, and the maximum change rate and the change range of the temperature are determined based on the temperature fluctuation curve to determine whether the fluctuation evaluation value is adjusted to re-determine the performance grading of the diode. According to the invention, the performance detection efficiency of the diode is improved.

The invention relates to the technical field of battery pack evaluation, and discloses an echelon utilization power battery evaluation method, which comprises the following steps: performing appearance and smell inspection, and screening batteries without damage, liquid leakage and peculiar smell; safety performance tests are sequentially carried out, and the safety performance tests comprise insulation tests, voltage-withstanding tests and elimination of unqualified batteries; performing dynamic environment simulation, performing health state detection through room-temperature and high-low-temperature charging and discharging, rate testing and internal resistance analysis, and evaluating residual capacity and consistency; a high-precision universal meter is adopted for voltage consistency evaluation, the resolution ratio is 0.1 mV, and the measurement error is smaller than or equal to + / -0.5 mV; the temperature consistency is detected by a distributed temperature sensor, the precision is + / -0.5 DEG C, and the sampling interval is less than or equal to 2s; bMS function verification is carried out, and SOC estimation and voltage / current measurement precision are calibrated; and integrating the detection data, and generating a battery health state report and echelon utilization suggestions. The detection efficiency and safety are improved, the resource utilization rate is maximized, and the cost is reduced.

The invention discloses a TBOX offline detection system, and relates to the technical field of offline detection. The feedback states of the five groups of indicator lamps are controlled through an ECU, namely, a light 3 is lightened after binding succeeds, a light 5 is lightened after remote shutdown, a light t1 is lightened after first-stage vehicle locking and 2V is displayed by a universal meter, and a light t1 and a light t2 are lightened after second-stage vehicle locking and 0V is displayed; the 279 ECU simulates a vehicle control unit, virtual vehicle number binding and unbinding are input through the cloud platform, and a relay is controlled to switch a power supply. When a vehicle is searched, the buzzer responds, and the rack integrates all the modules to realize physical connection and operation. The detection includes connection initialization, function detection, fault simulation and data storage, and efficiency and accuracy are improved. According to the invention, the detection efficiency is improved through the fast-plug wire harness and an automatic instruction, and the time consumed by a single machine is shortened to 15 minutes or less; errors are reduced through voltage simulation and acousto-optic feedback, and the fault omission ratio is reduced; the real-time evidence storage of the cloud platform ensures the data traceability, supports multi-dimensional retrieval and report generation, solves the problems of low efficiency, large error and difficult traceability of the traditional scheme, and improves the detection reliability and standardization level.

The invention discloses a metal material electrochemical polishing optimization method and system based on an LSV curve, and relates to the technical field of electrochemical polishing, an electrochemical polishing system and equipment are configured, and the system comprises an electrochemical polishing tank, a high-power power supply with a scanning function and a high-precision universal meter for receiving trigger signals; setting an external trigger signal, and determining a measuring range, an acquisition speed, a cycle index and trigger edge selection. According to the invention, the LSV curve is accurately monitored, the current limiting platform area is identified, the constancy of the current value in a certain potential range is reflected by using the stability index of the current limiting platform area, the width of the current limiting platform area is measured by using the width index of the current limiting platform area, and the current size index is analyzed to observe the size of the current limiting. The polishing parameters are automatically adjusted according to the indexes of stability, width and current magnitude, it is ensured that the optimal conditions are kept all the time in the polishing process, and therefore the high-precision and consistent polishing effect is achieved.

The automatic test system comprises a primary direct current source, an industrial personal computer, a tested power supply, an electronic load and a universal meter, the tested power supply is the programmable power supply, the primary direct current source is connected with the input end of the tested power supply and used for supplying power to the tested power supply, and the output end of the tested power supply is connected with the electronic load and used for supplying power to the electronic load. The universal meter is connected to the output end of the tested power supply and is used for measuring the output voltage of the tested power supply; the primary direct current source, the tested power supply, the electronic load and the universal meter are respectively connected with the industrial personal computer, and the industrial personal computer realizes control and data backward reading of the tested power supply, the electronic load, the universal meter and the primary direct current source through a communication interface. Compared with a manual test method, the automatic test system provided by the invention can realize automatic test by controlling the primary source, the electronic load, the programmable power supply and the universal meter only by setting up a test environment by a tester, so that the test efficiency is improved, and the labor cost is reduced at the same time.

The invention belongs to the field of tapping machine fault early warning, and particularly relates to a tapping machine fault early warning mechanism and early warning method for battery cabinet machining, which comprises a tapping machine, a tapping machine brake system, a workbench, a fixing module, a gravitation early warning module, a tightening module, a counting early warning module, a pressing module and a power connection detection module, the fixing module is used for keeping the tapping machine stable during power-on detection; the gravitation early warning module is used for displaying the distance that the assembly is pulled by gravitation generated by the drilling and tapping brake coil and the brake clutch plate when the tapping machine is powered on; the tightening module is used for limiting the position of the drilling and tapping brake back plate without preventing the drilling and tapping brake back plate from rotating; the counting early warning module is used for counting the number of rotation turns of the end not passing through the brake system and the end passing through the brake system. The pressing module is used for temporarily fixing the detached brake coil to be tested; and the electric connection detection module is used for detecting whether the inner wall coil of the brake coil to be detected is in good access or not and whether the insulation effect of the insulation coating is perfect or not by using a universal meter.

The utility model discloses a battery cell performance test and electric quantity automatic equalization tool, which comprises a charging and discharging device, a digital multimeter and a bottom plate, the charging and discharging device is electrically connected with the digital multimeter, and the bottom plate is connected with a first fixing plate and a second fixing plate which are oppositely arranged. A limiting plate for fixing the battery cell is arranged between the fixing plate I and the fixing plate II on the bottom plate; the first fixing plate is connected with a sliding rod, the end, away from the limiting plate, of the sliding rod is connected with a push-pull clamp, the end, close to the limiting plate, of the sliding rod is connected with a first pole piece, the side, facing the limiting plate, of the second fixing plate is connected with a second pole piece, and the first pole piece and the second pole piece are connected with charging and discharging equipment and a digital multimeter through connecting wire harnesses respectively. The bottom plate is provided with a supporting plate used for being connected with and supporting the push-pull type clamp. According to the utility model, the rapid, reliable and safe connection between the battery cell and the test equipment can be realized, multiple types of battery cells can be compatible, the voltage can be automatically detected, and the electric quantity required to be balanced can be calculated for electric quantity balancing.

The invention discloses a ring-down light cavity precision pressure control method and device based on enhanced data-driven PID, and the method comprises the steps: 1) building a ring-down light cavity pressure control device, and integrating a pressure sensor, a proportional valve, a digital multimeter, a DC power supply, a vacuum pump and other key parts; 2) acquiring a proportional valve driving voltage and a pressure feedback signal based on LabVIEW, and constructing a discrete time ARX model of the system; (3) on the basis of the model residual error and the real-time error, an enhanced data driving algorithm is adopted to carry out online self-adaptive updating on PID parameters; 4) filtering high-frequency noise by using a second-order Bessel low-pass filter to improve the signal stability; and 5) realizing closed-loop control under the LabVIEW platform, and monitoring and maintaining the operation performance of the system in real time. The method has the advantages of model self-learning, parameter self-tuning, high robustness, high control precision and the like, is particularly suitable for scenes such as high-precision spectral measurement with extremely high requirements on pressure stability, and has remarkable engineering practical value and popularization and application prospects.

The automatic testing device comprises a verification mother board, a verification daughter board, a program control direct current power supply, a digital multimeter, an angle simulation instrument, a signal generator and an upper computer, and the upper computer is provided with upper computer software of the automatic testing device for the synchronous-to-digital converter. Power input, reference input voltage and angle synchronous input signals needed by the synchronous-digital converter are provided, and normal work of the two-channel synchronous-digital converter is achieved. Synchronous conversion angle signals and reference voltage are input through the angle simulation instrument, the converter outputs corresponding binary bit angle digital signals, and the controller collects the corresponding angle digital signals, converts the angle digital signals into angles and transmits the angles to the upper computer through a serial port. And the high and low levels output by the synchronous-digital converter are measured by the digital multimeter and then are transmitted to the upper computer. And finally, the upper computer judges whether the standard is reached or not. Test indexes comprise shaft angle conversion, resolution, output high level, output low level and the like.

The invention belongs to the technical field of avionics detection, and particularly provides a rapid fault detection system and method for an avionics equipment transmitter, and the system comprises an electronic equipment detection system, an auxiliary device, an oscilloscope, a frequency spectrograph, a digital multimeter, a high-voltage probe and a current clamp which are connected through a cable. And a ground wire of the auxiliary device is connected with the avionics equipment. According to the invention, fault detection and positioning of components can be carried out by means of a complete machine to which the transmitter belongs without splitting a product to be tested, particularly, fault components are determined under the condition that the high voltage is applied to the transmitter, after various instructions, excitation signals and power supply troubleshooting confirmation are carried out, various functional loops are detected on line, and a special klystron is designed to replace a load. And finally, one-time fault positioning is realized, so that the fault positioning efficiency of the product is improved, and continuous power-on startup verification is reduced.

The invention discloses a multifunctional automatic aging system and method, and the system comprises a multi-parameter measurement module, an integrated oscilloscope, a universal meter and a temperature sensor, and is used for measuring the output voltage ripple, the output voltage value, the output current value and the surface temperature of an aging module in real time; the data comparison and judgment unit is used for automatically comparing the real-time measurement data of the multi-parameter measurement module with a preset standard value, recording unqualified data and identifying the corresponding aging module; the abnormity monitoring and processing unit is used for monitoring over-temperature, over-current and overload abnormal states in the aging process in real time, triggering alarm and executing preset processing operation; the database module is used for storing all test data and supporting production process tracking and problem tracing based on the stored data; the report generation module is used for automatically screening test data according to customer requirements and generating a standardized test report; and the control software unit is provided with modules for setting aging time, selecting models of products to be tested, configuring test functions, reporting templates and the like.

The invention discloses an automatic test system for detecting an IO port on an MCU controller, and particularly relates to the technical field of automatic test and hardware-in-the-loop verification, the system takes a TSMaster as an upper computer, a programmable power supply, a digital multimeter and a controllable relay matrix are combined, and input injection, output measurement and controlled power supply disturbance are realized through a CAN / Ethernet / SCPI. The system comprises an input injection and channel switching module, an output drive and high-resistance isolation module, a power supply disturbance and alarm verification module, a unified acquisition and self-calibration compensation module, a criterion evaluation / report module, a regression module and the like, completes alignment and online small signal calibration and crosstalk compensation under a unified time base, constructs a minimum evidence unit, and implements interval criterion and time sequence robustness evaluation. And outputting an auditing report and triggering regression scheduling to realize high coverage of IO port functions and boundary working conditions and repeatable verification.

Provided is a method for the simultaneous determination of parameters, in particular of at least two, three or four parameters, of at least one resin layer applied to at least one carrier material by recording and evaluating at least one NIR spectrum in a wavelength range between 500 nm and 2500 nm, preferably between 700 nm and 2000 nm, more preferably between 900 nm and 1700 nm, and particularly advantageously between 1450 nm and 1550 nm, using at least one NIR measuring head, in particular at least one NIR multimeter head.

The invention discloses a terahertz detector linearity calibration device and method. The terahertz detector linearity calibration device comprises a terahertz radiation source, a monitoring detector, a baffle, a terahertz film attenuator, a diaphragm, a standard terahertz detector, a digital multimeter, a computer and measurement and control software. The terahertz radiation source is used for radiating parallel or divergent terahertz wave beams; the monitoring detector is used for monitoring the fluctuation condition of the terahertz radiation source; the baffle plate is used for being inserted into a terahertz light path when the noise of the detector is detected so as to play a role in cutting off the terahertz light path; the terahertz thin film attenuator is used for carrying out quantitative attenuation on terahertz power without changing the transmission state of a wave beam; the digital multimeter is used for measuring an electric signal output by the detected terahertz detector, and the electric signal is collected by the computer and sent to the data processing software, and then the linearity is calculated according to the linearity. According to the invention, the interference of the attenuator on beam transmission characteristics can be effectively reduced, so that the calibration precision is improved.

The utility model discloses a photodiode dark current testing device, comprising an LED lamp, a light shield, a dual-channel power supply, a desk type universal meter, a one-chip microcomputer control board and a multi-channel test board, the light shield is covered on the multi-channel test board, the multi-channel test board is provided with PD sockets having the same number as the channels of the multi-channel test board, and the PD sockets are connected with the desk type universal meter. The PD socket is composed of a 4P socket and Y-shaped sockets arranged side by side. After the scheme is adopted, the efficiency is greatly improved through multi-channel testing, and the vertical pins can be automatically tested through the design of the Y-shaped socket.

The invention discloses a testing device for a PCB (Printed Circuit Board). The testing device comprises a testing box body, a testing jig, a testing instrument and a control upper computer, a simulation battery module, a logic control module, an intermediate relay module, a reference BMS module and a power supply are arranged in the test box body; the simulation battery module outputs multiple paths of adjustable cell voltages for sampling of a PCB to be tested, the logic control module receives an instruction of an upper computer to control a test process, the intermediate relay module realizes signal switching and on-off control, the reference BMS module provides function parameter comparison, and the test instrument comprises an electronic load and a universal meter. The device is used for detecting parameters such as discharge performance, voltage and current. The test fixture is fixed and connected with a to-be-tested PCB, the contact port assembly can be replaced to adapt to different models, and the code scanning gun inputs test information and triggers a process. The device has the functions of multi-path voltage simulation, automatic signal switching and data acquisition and tracing, is modularized in structure and high in adaptability and expansibility, and can improve the batch detection efficiency and precision.

The invention discloses a standard harmonic voltage source based on pulse driving alternating current quantum voltage and a standard harmonic voltage source output method, a main controller of the standard harmonic voltage source reads power amplifier output voltage when a first switch is switched off, judges an interval in which the power amplifier output voltage falls, and switches a linked switch gear according to the interval in which the power amplifier output voltage falls; calculating an output voltage before compensation; when the first switch is closed, the first digital multimeter and the second digital multimeter synchronously sample and respectively acquire a differential pressure signal and a fundamental wave signal, and the main controller determines an amplitude error according to the acquired differential pressure signal and the fundamental wave signal and compensates the output voltage before compensation according to the amplitude error to obtain the compensated output voltage; and generating a code according to the compensated output voltage and sending the code to a JAWS quantum voltage generator, so that the JAWS quantum voltage generator decodes the code and then outputs a corresponding standard harmonic voltage signal, thereby realizing high-precision voltage control and improving the accuracy of voltage output.

The invention relates to the technical field of semiconductor material thermoelectric performance testing, in particular to a bismuth telluride sheet material Seebeck coefficient measuring device. The device mainly comprises a flexible measuring device and a data acquisition system, the data acquisition system is provided with a universal meter and a programmable power supply, the flexible measuring device is connected to the input end of the universal meter through a signal cable to transmit temperature and pressure signals of a thermocouple, and the flexible measuring device is connected to the output end of the programmable power supply through a power supply cable to transmit the temperature and pressure signals of the thermocouple. And the universal meter and the programmable power supply are respectively connected to the computer through communication cables and are connected with the computer to realize data processing. Through the three-in-one design of flexible contact, synchronous sensing and temperature difference control, accurate measurement of the Seebeck coefficient is realized. Through actual measurement, the temperature control precision of the device is + / -0.1 DEG C, the voltage acquisition resolution is 0.1 mu V, and the Seebeck coefficient measurement error is less than 2%.

1. The name of the design product: intelligent multimeter. 2. The use of the design product: for voltage, current, resistance, capacitance, frequency, duty cycle, diode, temperature, etc. measurement and detection. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: perspective view 1.

The utility model provides a multi-electrical-quantity data acquisition device based on a universal meter card, and relates to the field of electrical quantity data acquisition, and the device comprises an input module which comprises a plurality of signal input channels; the switching matrix module is connected with the input module; the universal meter card is connected with the switching matrix module; the embedded computer is connected with the universal meter card; the switching control module is respectively connected with the switching matrix module and the embedded computer; wherein the embedded computer generates and sends a control instruction, the switching control module receives and decodes the control instruction to generate a control word, the switching matrix module performs multi-selection on multiple paths of input signals in the input module according to the control word and sends a selected signal to the universal meter card, and the universal meter card measures the selected signal. And the measurement result is transmitted back to the embedded computer, so that the technical problems of high cost, large size and inconvenience in carrying of the whole device due to multiple signal types and multiple channels of the existing data acquisition device are solved.

1. The name of the design product: multimeter. 2. The use of the design product: tools for measuring voltage, current, etc. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: perspective view 1.

1. The name of the design product: multimeter shunt. 2. The use of the design product: used with multimeter to shunt current. 3. The design points of the design product: in shape. 4. The picture or photo that best shows the design points: perspective view 1.

The invention discloses equipment and a method for detecting one-point grounding of a voltage loop. The equipment comprises a processing control unit and a test loop, the processing control unit is in communication connection with the test loop; the signal input end and the signal output end are respectively in communication connection with the processing control unit; the adjustable equivalent resistor is also in communication connection with the processing control unit; the processing control unit is used for receiving a first feedback signal output by the signal output end, determining actual equivalent resistance according to the test signal and the first feedback signal, adjusting the resistance value of the adjustable equivalent resistor according to the actual equivalent resistance and receiving a second feedback signal; and judging whether the to-be-tested voltage loop has a grounding fault according to the second feedback signal and the test signal. According to the technical scheme, the problem that a universal meter cannot be used for measurement at one-point grounding position is solved, and operation interval protection maloperation is not prone to being caused. Meanwhile, the adjustable equivalent resistor is arranged to change the parallel resistance of the distributed capacitors according to the feedback signal, thereby achieving the effect of enhancing the signal.

The invention provides a universal aviation cable detection device and method.The device comprises an industrial personal computer, an aviation cable core resistance value measurement host, a test cable and an aviation cable qualification self-judgment system.The measurement host comprises a power supply module, an output board card, an input board card and a power-on indicator light; the self-judgment system comprises a serial port communication module and a qualification self-judgment module integrated in an industrial personal computer. According to the working principle, a constant voltage source is applied to a measured aviation cable through the output board card, a voltage signal is collected through the high-resistance-state AD collection module, calculation and analysis are conducted through the qualification self-judgment module, and high-precision measurement of the resistance value of a cable core, automatic judgment of the line sequence state and intelligent quality evaluation based on a multi-stage configurable threshold value are achieved. Therefore, the problems of low core-by-core measurement efficiency and insufficient precision of a traditional universal meter are solved, and the automation degree and the reliability of aviation cable detection are remarkably improved.

The utility model discloses a safe and simple grounding test liquid crystal display screen, which comprises a lower iron stand, a backlight module and a display module, and is characterized in that the lower iron stand comprises a bottom plate and a side wall extending upwards from the edge of the bottom plate; the backlight module is arranged on the upper surface of the bottom plate; the display module is arranged above the backlight module, an FPC is led out of the display module, a grounding leakage copper block is arranged on the lower surface of the FPC, a conductive double-sided adhesive is pasted on the lower surface of the grounding leakage copper block, a large-size grounding test leakage copper point is arranged on the upper surface of the FPC, and the conductive double-sided adhesive is pasted on the lower surface of the grounding leakage copper block. And the FPC positioned at the grounding copper leakage block and the grounding test copper leakage point is bent to the lower surface of the bottom plate and is adhered and fixed through the conductive double-sided adhesive. The probe of the universal meter can easily test the conductivity and the resistance value of the grounding test copper leakage point and one corner of the lower iron frame, the probe is very convenient to test and operate in the process, and even if the probe damages the grounding test copper leakage point in the test process, the use of the FPC is not influenced.

The utility model relates to a special assembly for a test connecting line of an intelligent calibration system device of a digital multimeter. The special assembly comprises a detection line, a detection socket, a detection plug and a V-shaped clamping jaw, the detection plug is a banana head, and the upper end of the detection plug is provided with a V-shaped groove. The detection line comprises a first detection line and a second detection line, two ends of the first detection line and the second detection line are provided with detection plugs, the detection plug at one end is inserted into the detection socket during detection, and the detection plug at the other end is inserted into the detection hole of the digital multimeter to be detected; the opposite faces of the V-shaped clamping jaws are provided with V-shaped protruding blocks matched with the V-shaped grooves of the detection plugs, the upper ends of the V-shaped clamping jaws are provided with V-shaped grooves, the V-shaped grooves and the V-shaped protruding blocks of the V-shaped clamping jaws form a clamping structure, the detection plugs are prevented from sliding off in the grabbing process, the positions of the V-shaped grooves in the detection plugs are arranged to be higher than the tops of the low detection plugs, and grabbing of the V-shaped clamping jaws is facilitated. And the detection socket is connected with the measurement standard equipment to transmit measurement signals, so that the digital multimeters of various models can be detected.

The utility model discloses an electrical instrument with a protection structure, which relates to the technical field of electrical instruments and comprises a universal meter with a shell body and a protection assembly. The protection assembly comprises a protection unit, a rotating and overturning unit and a supporting unit. The protection unit is matched with the protruding edge to achieve scratch-proof protection of the front end of the shell body. The rotating and overturning unit is used for achieving the effects that the protection unit is opened in a rotating mode and connected with the rear end of the shell body in a sleeving mode. According to the utility model, through the arrangement of the protection assembly, the front end of the shell main body is sleeved with the protection cover, so that the front end of the shell main body can be protected, the situation that an external object is in contact with a display screen at the front end of the shell main body and scratches the display screen is effectively avoided, and meanwhile, the protection cover can be sleeved with the rear end of the shell main body through horizontal rotation and vertical overturning; therefore, the front end of the shell main body is exposed to facilitate measurement operation, and the protective cover does not interfere with the use of the universal meter.

The invention relates to the technical field of universal meters, and provides an automatic power-on and power-off universal meter and a control method thereof, and the automatic power-on and power-off universal meter comprises a handheld state detection unit which is used for detecting whether a user holds a meter pen of the universal meter or not and generating a corresponding state signal; the measuring unit is used for measuring a resistance value and / or a voltage value of a meter pen contact point; the control unit is used for controlling the multimeter to be switched to a power-on state when the state signal indicates that the meter pen is held by hand; if the effective resistance value or the effective voltage value detected by the measuring unit is received, the power-on state is maintained; and if the state signal indicates that the meter pen is not held by the hand, and the received resistance value detected by the measuring unit is infinite and the voltage value is smaller than a preset voltage threshold value, the multimeter is controlled to be switched to a power-off state. On the premise that a physical key is cancelled, user intention detection is achieved, and quick and reliable response can be ensured.