What instrument measure power? The question is quite relevant, since at present there is an electric network everywhere. Almost nothing works without electricity. It is not surprising that this led to the enormous popularity of instruments measuring the performance of such networks. An important fact is that power measurement can only be done in watts. However, in some cases there is a need to convert watts to kilowatts. Most often this is done for the convenience of calculations.
General description of electrical networks
Power is one of the three main parameters that characterizes the electrical network. This parameter reflects the amount of work that the current strength performs in one unit of time. It is important to understand here that the total power of all connected devices in the network should not exceed that supplied by the supplier. If this happens, negative consequences are possible, starting with the failure of the equipment and ending with a short circuit and subsequent fire. In order to avoid such troubles, power meters called wattmeters were invented.
It is important to understand that in a DC circuit, this parameter can be measured without using this device. To do this, use multiplication. The values of voltage and current in the circuit are multiplied. However, the same method cannot be dispensed with in the AC circuit. It was for such networks that measuring instruments and tools were invented.
Use of equipment
The main sources using these units were workshops involved in the repair of electrical appliances. Actively use power meters in the electric power industry, as well as engineering. Another fairly common model is household appliances. The main buyers of such products are electronics lovers, computer owners or just people who want to save on electricity.
One small fact. In some cases, it is necessary to convert watts to kilowatts. Most often this is done in industrial sectors, where the power is so high that if measured in W, the values will be too large. When converting units of measure, there is such a rule: 1000 W is 1 kW.
Most often, devices are used for such purposes as:
- determination of the power of an individual unit;
- testing the entire electrical circuit or its individual parts;
- device health monitoring;
- metering of electricity consumption by all connected devices.
A brief description of the types of devices
It is important here to begin with the fact that before you begin to measure power, usually measure the current strength and voltage. Based on the selected measurement method, the subsequent conversion and output of the obtained data, there are distinguished types of measuring instruments and tools, such as digital and analog.
Analog types of devices differ in that they have a semicircular scale, as well as a moving arrow. They are also divided into two smaller groups - self-recording and showing. These devices reflect the power of only the active section of the circuit. The device measures in watts (W).
Digital power meters (wattmeters) can be used to measure both active and reactive power. In addition, the functionality of this device is much wider, since not only power, but also current, voltage and energy consumption over time are displayed on its display. Another advantage is that all values can be output remotely, that is, to the operator’s computer.
The essence of analog devices
If we talk about devices of the analog type for measuring power, the most accurate and often used devices of the electrodynamic system.
The principle of operation of this power meter is based on the operation of two coils. One of them is characterized by the fact that it does not move, its resistance is small, as is the number of turns. But the winding, on the contrary, is quite thick. The second instance is the opposite of the first. That is, the coil moves, the thickness of the winding is low, but the number of turns is quite large, which is why the resistance is also increased. The connection of this device is parallel to the load. In order to avoid a short circuit between the internal coils of the device, the device is equipped with additional resistance.
The essence of digital devices
The principle of operation of these power meters is more complicated than that of the previous type. The reason for this was that power is not measured directly. The basis of the operation of the device lies in the fact that first preliminary measurements of current and voltage are made. In order to conduct them, it is necessary to connect a current sensor in series with the load, and in parallel with a voltage sensor. These units can be made on the basis of thermistors or measuring transformers.
Instantaneous values obtained through an analog-to-digital converter are transmitted to the microprocessor available to the meter. At this point, the necessary calculations are made, thanks to which you can get the value of active and reactive power. The final results of all measurements are displayed on the display of this device, as well as on the display of those devices that are connected to it. Optical power is not measured by these types of devices.
Household appliances
Today, a wattmeter has become a fairly common and convenient device in everyday life, with which you can measure the consumption of electrical energy in a house. This model is a portable version of the device, with which power is measured in a separate area. Thanks to this, it becomes possible to calculate the material costs that will be spent on electricity, if you leave the network with the same parameters.
This device is quite convenient if you need to plan the expense of funds, and also help to optimize some sections of the home chain.
Household power meters
This unit belongs to the digital group of devices. In its appearance, it strongly resembles an adapter or an adapter, which has an indicator type display. In addition, on the case there are several buttons that control the operation of the device. The main purpose of this device is to register and display on the screen the results of power consumption by any household device that connects to the network through it. There are a lot of such parameters, and this is not only the power consumption. If you introduce a specific tariff, the device can even show the amount of material resources that will be paid for the operation of this particular device. It can also record radiation power.
Instrument Functions
In addition to the usual indicators, this device is also able to record values such as peak power and peak current value. In addition, there are several other functions. The device also shows the current time, can work like a regular real-time clock. Another possibility of using the device is an audible alarm, which will work if the device starts to consume more power than the user sets manually.
The buttons on the device can be used to manually configure the functions of the device. It is possible to set the maximum permissible radiation power, set the cost of a kilowatt per hour, etc.
In terms of operation, this device is very simple. For it to work, you need to connect it to the network, that is, plug it into a power outlet. Next, you need to connect the plug of the instrument under study to this household wattmeter. The display of all parameters of the connected device will start automatically.
From the main parameters of this device, we can distinguish that almost any household equipment can be connected to it. The total maximum power of devices should not exceed an indicator of 3600 watts. Also, do not exceed the current strength of 16 A.