A Digital Multimeter (DMM) is a versatile electronic measuring instrument used to measure various electrical parameters such as voltage, current, resistance, capacitance, frequency, and continuity. It combines several measurement functions into a single compact unit, making it an essential tool for electricians, engineers, and maintenance technicians. Unlike analog multimeters, digital multimeters display readings on an LCD screen, ensuring higher accuracy, faster response, and easier data interpretation.

The working principle of a digital multimeter is based on an analog-to-digital converter (ADC) that transforms the analog input signal into a digital output, allowing precise numerical display of the measured value. Some advanced DMMs are equipped with True RMS (Root Mean Square) measurement capability, enabling accurate readings even for non-sinusoidal waveforms. Modern multimeters also feature auto-ranging functions, eliminating the need for manual range selection and reducing the chance of measurement errors.

Digital multimeters are widely used across multiple industries. In electronics and electrical maintenance, they help diagnose faults, verify circuit continuity, and measure battery or power supply voltages. In industrial automation, DMMs are employed for equipment testing and system calibration. In research laboratories, they assist in circuit design, component evaluation, and precision measurement. Portable handheld models are ideal for field service, while benchtop models are used for high-accuracy laboratory testing.

Many DMMs now include additional features such as data hold, min/max recording, temperature measurement, backlit displays, and USB interfaces for data logging and analysis. Their durability, reliability, and versatility make digital multimeters indispensable in modern electrical and electronic applications. Whether for simple household use or professional industrial diagnostics, the digital multimeter remains a fundamental tool for accurate measurement and safe operation in all electrical systems.

Performance Characteristics

1. Provide multiple loop control nodes,can be used for the alarm, trip control

2. Support for fire control, remote cut offthe fault circuit

3. Convenient installation, wiring is simple

4. To be completed by SCADA, PLC ina variety of communications softwarenetworking

Technical Index

Accuracy of measurement

1. Voltage: level 0.5

2. Current: level 0.5

3. Active Power: level 0.5

4. Reactive Power: level 0.5

5. Power Factor: level 0.5

6. Frequency: ±0.02HZ

7. Active Electric Energy: class 0.5s orclass 0.2s

8. Reactive Energy: Class 1 or Class 2

Signal Input

1. Connection Mode: three phase four wires

2. Rated Voltage: AC 0-600V

3. Rated Current: AC1A,AC5A

4. Overload Voltage: 1.2 times ( Continued ),

5. 2 times /second ( instantaneous )

6. voltage:<1VA/ phase; current:<0.4VA/phaseImpedance:>300KΩ,current: <20mΩThe Frequency: 45~65Hz

Auxiliary Power Supply

1. Working range AC 220V

2. Power Consumption: <4VA

Function module

1. Communication Interface: 1 way RS-485 communication, Modbus-RTU protocol

2. Baud Rate:1200~9600bps,the default is 2400bps  Switch Input: 4 ways

3. Switch Output:4 ways( capacity:AC 250V5A. DC 30V15A)

4. Transmission Output: 3 ways(analog output: 0/4~20mA or 0~5/10V)

5. Electric Energy Pulse Output: 2 ways

6. Constant: 8000imp/KWh(Kvarh)
   

Please note that above is our normal function,please contact us for customizing special products.