功率计校准服务

With the aim of serving customers with the best after-sales services, EMIN Vietnam has established the Equipment Inspection - Calibration - Repair Service Center. With the support from numerous equipment manufacturers in the world, EMIN Vietnam possesses well-prepared calibrating instruments. EMIN Vietnam has successfully repaired and calibrated specialized equipment in Vietnam, ensuring the quickness, effectiveness and convenience for customers. Only few technical trading company in Vietnam do possess this technical capacity including EMIN Vietnam.


>> Wattmeters
Wattmeter is a measure of electric power (or rate of electrical energy supply) in watts of any circuit.
- Electromagnetic wattmeter is used to measure power at audio frequency and DC. That drains capacity at radio frequencies requiring a dedicated type.


>> Other information
♦ Classification
Watt meters are classified according to the rated power level:
  • The millimeter-watt meter measures the power in experiments.
  • Watt meters measure electricity in general consumption.
  • Kilo and Mega watt meters measure electricity in power plants.
Classified by number of phases, there are single-phase and three-phase Watt meters, of which three-phase is only available in the power industry.
Classified according to the measuring circuit, there are electrodynamic and electronic Wattmeter.

♦ Dynamic Wattmeter
- Traditional analog Wattmeters belong to the electrodynamic instrument category. It has a fixed coil pair of current, and a movable winding voltage coil.
The current windings are connected in series with the circuit, while the voltage winding is connected in parallel. In addition, on the analogue wattmeter, the coil of the needle carrier voltage moves across the scale to indicate the measurement result. An electric current flows through the coil to create an electromagnetic field around the coil. The strength of this field is proportional to the current and in phase with it. Voltage coils, as a general rule, have a high-value resistor in series to reduce the current flowing through it.
The result of this arrangement is that on a DC circuit, the needle deflection is proportional to both the current I and the voltage V, thus consistent with the equation P = VI.

♦ Electronic Wattmeter
Electronic wattmeter is designed with microcontroller, for compact and reliable meter.
- The block diagram of the basic meter consists of a circuit for sampling current and voltage, taking the RMS and digitizing it and sending it to the microcontroller to perform the multiplication. Results are fed to an LCD or LED display unit, and can have a standard output for directly transmitting data to another device, commonly used today as a USB port. The sampling rate is usually a few thousand numbers per second.
Extensive gauge types have more complex functions and a higher cost. Thanks to the microcontroller and built-in memory the device can calculate and store RMS voltage, RMS current, VA, power (watts), power factor and kilowatt-hour power.
However, the wattmeter differ significantly in calculating the correct energy consumption, especially when the actual power is much lower than the VA (highly reactive load, e.g. electric motor). . Simple gauges can be calibrated to meet the precision specified for the sine waveform. Waveforms for switching power supplies currently used for many electronics can be very far from sinusoidal, leading to unspecified errors and can be large at any power source. This may not be specified in the instructions for use.

For further information about calibration service, visit our website at: https://emin.vn/en_US/calibration-inspection-service-985/pc.html


For further information and calibration requirements, Please contact

Equipment Inspection - Calibration - Repair Service Center - EMIN Vietnam JSC 

 Adress: No 11, Hoang Cau Moi Street, Trung Liet Ward Dong Da District, Ha Noi City

Email: hn@emin.vn - Hotline: 097.251.2864 (Mr. Truong)