How to Measure Wind Speed with an Anemometer

How to measure wind speed with an anemometer

All people around the globe probably check on the internet or watch the weather forecast on the TV. Have you ever wondered how weather forecasters make measurements of the wind speed? What kind of device do they use to measure it accurately? Let’s take a closer understanding about it!

Yellow Jacket 68915 Anemometer Kit

What device is used to measure wind speed?

An anemometer is an equipment that provides the measurement of wind speed and wind pressure. It is a profitable tool for meteorologists, who study weather conditions. This tool also helps pilots to determine the air speed during the flights. The most usual anemometers have 3-4 cups attached to horizontal arms.

These arms are attached to a perpendicular rod. When the wind blows, cups start turning that involve the rod spinning. The anemometer counts the number of turns to measure the wind speed. The wind speed isn’t steady, because there can be gusts and lulls. 

Types of anemometers and how to measure a wind speed with them

R.M. young Cup Anemomener

The most common type is cup anemometer. Three or four cups turn across their spindle due to wind and it provides the rod rotating to measure the wind speed. Three-cup anemometers are often used in meteorology stations. The plus of the cup anemometer is that they have a huge wind measurement spectrum. Such anemometers are cheap and they are made of different materials such as aluminum and polycarbonate.

Propeller anemometers

Propeller anemometers consist of three- or four-blade propellers. These propellers turn around the horizontal spindle. They are set in front of a wind indicator and the rotating plane is installed to the wind direction and such way the anemometer's speed is equal to the wind speed. The rotating plane should always be adjusted with the wind direction. The wind indicator is identical to the shape of the aircraft, which provides a good speed.

Hot-wire anemometer

Hot-wire anemometer includes a speed measuring tool that changes the flow speed signal into electrical signals. The working concept is to set a thin heated by electricity metal cable (hot wire) in the air current. The heat dissolution amount of the cable in the air current is relevant to the flow speed. It is a high-speed tool that can be determined even at low speeds.

Handheld anemometer

Handheld anemometer is a compact wind speed measuring tool that can read speeds up to 180 miles per hour (30 m/s). This equipment is battery-powered. Such an anemometer is a great device for determining wind direction or wind speed during camping, hiking, sailing and other outdoor activities. It is compact and light to carry during the activities and needs no settings.

Ultrasonic anemometer

Ultrasonic anemometer measures a wind speed and wind direction by using sound pulses to determine frequency difference at the endpoint to measure wind speed and direction. The velocity speed of sound waves in the actual atmosphere is equal to the velocity speed of sound waves in the static atmosphere and the air current speed in the atmosphere. This type of equipment is better than others, ‘cause it provides long-term work during all weather conditions.

Pressure anemometer

Pressure anemometer determines the wind speed using the difference between entire wind pressure and static pressure. One nozzle is covering the direction of air current and senses the entire pressure of the air current and the other nozzle is behind the direction of the air current. The induced pressure is lower than the static due to the suction effect.

Pitot-tube anemometer

Pitot-tube anemometer consists of an entire and static pressure probe. A small opened hole at the top of the equipment's head is used to feel the entire pressure of the fluid. Such a device is used to measure positive, negative or differential pressure of the gas pressure as well as to measure wind speed and air volume.

Difference between anemometer and weather vane

Difference between anemometer and weather vane

It seems that anemometer and weather vane are the same equipment, but NO. A weather vane determines the direction of the blowing wind. It can often be installed to the house’s roof. 

The anemometer is an equipment that measures the speed of the wind according to the speed of cups or turbines spinning.  Some anemometers can measure wind direction as the speed and others can determine only the wind force. 

Where is the anemometer used?

The anemometer can be used to determine the speed of wind before surfing or sailing. Technicians can use it for measuring the output of a unit they are troubleshooting. Meteorologists use an anemometer during identifying the forecast. Some anemometers are installed in huge complex weather stations to provide weather forecasts on a combination of all the data. Anemometers can also be used in laboratories or the pharmacy industries  for the air duct analysis to balance HVAC systems.

Interesting fact* Nasa is thinking about a mission to Venus where it would be necessary to use the anemometer to measure the wind speed on the planet. Scientists believe that anemometers and other equipment will help to understand Venus's surface and atmosphere better.

anemometer used for

Anemometers can be compact, so you can take them in your hands and store them in the bag during the expedition or outdoor activities. However, they also can be a part of a vast weather station and installed to the rooftop of the building or in a wide open field. Features of the anemometer such as size, type and function depend on the field of activity the anemometer is going to be used.

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