Technology of Electrical Automatic

Important parameters of an electric meter

Electrical measurement device is a concept of general word. As we know, Multi-meter, installation type instruments belong to electrical measurement devices. Here, we mainly discuss how to choose installation type digital meters.

Well, digital meters, according to the function, can divide as follows: Voltage meter, Current meter, Active (Reactive) power meter, Frequency meter, Power Factor meter etc, including the all-in-one function type called intelligent multi-meter. This part mainly discusses some common sense.


Instrument accuracy

Electrical measurement devices include 7 classics: 0.1; 0.2; 0.5; 1.0; 1.5; 2.5; 5.0

The level refers to error percentage of instrument when it come full range.

For example, the accuracy of 193I-9X4 three-phase current meter manufactured by Blue Jay is 0.5 with input current of 5A. That is to say, when this current meter measures full range current of 5A, the maximum of error percentage won’t be 0.5

Another way to discuss device accuracy is called uncertainty level. We’ll talk it next time.


Digital meter and analog meter

Digital meter is known for its precise reading and high accuracy.

The strengths of the analog meter, according to the motion of pointer, we can know the change trend and scope.

Our company, specializing in “power control, power protection automation” equipments, is a fist-class manufacturer. We offer intelligent digital meters for energy saving and eco-friendly.


Power supply

Generally talking, power supply can divide three types, transformer power supply, switch power supply, and the battery.

Transformer power supply:

Strong anti-interference ability and anti-harmonic, but solo input voltage classic that DC not available

Switch power supply:

Wide input voltage range 70~250v Poor anti-interference ability, especially in heavy harmonic places like steel plant


Input measurement signals

The accuracy of DC is far higher than AC.

The true effective and average value

The multi-meter shows average digital of power parameters in a very short period of time.

Installation type meters precisely display power parameters digital in real time, having the characteristics of strong anti-interference ability anti-harmonic and frequency variation.


Optional functions

There are some optional functions, besides the general measurements.

Communication function: Supporting RS485 and MODU BUS protocol

Analog output function: 4~20mA

Control function: When the voltage is overload to setting value, the meter can alarm by relay output.


C/T ratio setting

The full range of current meter can be set based on installation transformer. And the setting value is any one of 5A~8000A according to our country standard.


Respond speed

Digital meters generally adopt specialized chip giving consideration to multi-functions and respond time is slow down. Only 3 ~ 5 digitals are available in one second.

Our company, Blue Jay Electronic digital meters can show 50 digitals in one second with high precision and strong stability. The respond seed is quite fast for customer satisfaction.


Other frequency meters

What we talked above is all about meters of frequency 50 Hz.

But there are some other frequency meters for special field application. Like digital meters of frequency 40 Hz are for aeronautical application, and meters of frequency 20 Hz for super audio power and transformer output current.

Blue Jay Electronic can satisfy customers’ need by manufacturing different frequency of digital meters.


Digital monitor software

When using digital meters with RS485 communication, customer generally has to write digital-monitor programmed manual. That is troublesome.


At last, thank you for reading.