One of the effective parameters in heat transfer is air flow and has speed and direction characteristics, therefore Speed measurement And the direction of the wind is very important, hence a tool called Wind gauge And anemometer is used. Anemometers are devices used to measure wind speed and Badnama Used for wind.
Anemometers or Enmometers According to the type of operation, they are divided into two categories, one group measures wind speed and the other group measures wind pressure. But since wind speed and pressure are related, the other can be calculated by measuring each of these two quantities. Anemometers or wind speed sensors are instruments used to measure wind speed with the utmost accuracy. A wind vane or wind direction sensor is a device that shows the direction of the wind. Wind turbines are usually built or installed on high places such as buildings or masts of boats and yachts. The basis of the wind vane is that its weight is equal on both sides of the axis of rotation, but the level of the windshield is different on each side. As soon as the wind blows, the wind turbine rotates so that the side with the lower wind surface is on the wind side.
The unit of measurement in Wind gauges These include feet per minute (ft / min), meters per second (m / s), kilometers per hour, miles per minute and Mach per hour, and so on.
Types of anemometers
Anemometers can be divided into the following types based on the type of technology used in them:
Anemometer is a vane made
of a impeller which is connected to a speedometer. In this type, instead of bowls, a vane in the form of air conditioners is used and the speed of the blades rotates in a clockwise or counterclockwise direction. The rotation of the blades is displayed by the speedometer display.
Ultrasonic or ultrasonic anemometer
We know that sound is transmitted by air molecules, and we also know that wind speed affects the speed of sound transmission. Sound is transmitted faster where there is wind than there is no wind. If you are in the direction of the wind and your friend calls you, their voice will reach you much faster than it reaches their ears, and vice versa, if you are in the opposite direction of the wind, your voice will reach you later. This cleverly sparked the idea Wind gauge Ultrasound is the use of frequencies above the human hearing range,wind speed Measures.
In this anemometer, two or three sound receivers are installed on bowls at right angles to each other and electronic circuits inside Wind gauge They measure the difference between the reciprocating sound. If this difference is short, the wind is faster and if it is high, the wind speed is not high.
Laser anemometer Infrared
in this anemometer considers two rays of light that are perpendicular to each other (you can create a right angle between these two rays with a silver mirror that absorbs some light and reflects the rest) and with the passage of wind Among these lights, wind speed and wind speed are measured based on the speed of change of light angle. If you put this device in an electrical circuit and measure the speed of angle change, you can get the wind speed.
Definition of anemometer (Anemometer)
Anemometer (Anemometer) is a device for measuring wind speed (air flow).
Flowmeter or flowmeter is a tool to measure the volume of material passing through time.Accurate measurement Flow is very important due to lower costs and the purchase of a certain amount of material such as oil exchanges and household gas meters.
Classification of wind gauges or wind speedometers Wind
gauges or wind speed meters are divided into two categories. The group that measures wind speed and the second group is the group that measures the flow or flow of wind. Wind speedometers or anemometers are designed to measure speeds such as meters per second (m / s). With the help of wind speedometers, the speed of moving air can be measured. In the thermometer – wind gauge (wind speed gauge) through the presence of a sensor inside Wind gauge There, the air temperature is detected.
The unit of measurement in wind speedometers are feet per minute (ft / min), kilometers per hour, meters per second (m / s), miles per minute and Mach per hour, and so on.
The second category is wind flowmeters, which measure the volume of wind passing through a specific area per unit time. The units for measuring the amount of moving air passing through the air duct are cubic meters per minute (CMM) and cubic feet per minute (CFM). To measure flow, you must first enter the desired area in terms of square meters in the device and then The amount of transit volume will be displayed.
Types of wind speed probes:
• Blade or butterfly
probe • Cup
probe • Hot wire probe
Application of an anemometer:
- To analyze the performance of car engines.
- Inspection test of industrial air conditioners and fans.
- Measurement of ducts and ducts.
- Sensitive centers such as calibration laboratories for air pressure testing
- Check and review and analyze the working conditions of devices such as hoods that have a suction mode
- Monitor ionized current output
- Check the ventilation system