The wind speed is an important meteorological parameter. There are different instruments used to measure and record wind speed. Let’s look at some of the common devices used for measuring wind velocity.
An anemometer is the most widely used device for measuring wind speed. It consists of 3 or 4 hemispherical cups mounted on horizontal arms. When the wind blows, it rotates the cups. This rotation generates an electric signal proportional to the wind velocity.
There are many types of anemometers:
- Cup anemometers: Have rotating cups on a vertical shaft.
- Propeller anemometers: Have a rotor with 3-4 blades that spin with the wind.
- Ultrasonic anemometers: Measure wind speed using sound waves.
- Laser Doppler anemometers: Use laser beams to detect wind velocity.
Anemometers provide accurate real-time measurement of wind flow. They are used at meteorological stations, wind farms, aviation centers etc.
A weather vane is a traditional device that shows the direction of the wind. It has an arrow-shaped object mounted on a vertical spindle. As the wind blows, it aligns the spindle to point the arrow in the downwind direction.
Weather vanes are not accurate measuring instruments. But they visually indicate the wind orientation. This helps people determine the source of the wind.
A wind sock also shows the approximate wind direction. It is a textile tube shaped like a cone, mounted on a pole. The open end of the cone faces the wind.
As the wind speed increases, the tube expands and aligns itself horizontally showing the wind orientation. The more inflated the wind sock, the stronger the wind speed.
Wind socks provide a quick visual reference for wind direction and relative velocity to pilots and meteorologists.
A Pitot tube has an L-shaped pipe facing the wind stream. It measures dynamic pressure caused by the wind, which indicates the wind velocity. These are installed on aircraft to determine airspeed.
An anemograph is a device that provides a graphical record of wind speed over time. It has a 3-cup anemometer connected to a pen which marks the wind speed on a paper chart attached to a drum.
This creates a historical log of wind readings. Met agencies use anemographs to study wind patterns.
Portable handheld anemometers are used to measure wind velocity in the field. These compact battery-operated devices have a small propeller and digital readout.
By holding it in the airflow, one can get instant wind speed data for analysis. Handheld anemometers are useful for environmental studies, weather enthusiasts, wind turbine site surveys etc.
Wind Speed Apps
Today various mobile apps use the phone’s air pressure sensor to detect slightest air movements. After calibration, they can determine the approximate wind speed.
Though not very precise, such apps generate satisfactory wind speed estimates for everyday use.
Wind Speed Meters for Sports
For sports like cycling, sailing, golf etc special wind gauge meters measure the wind velocity experienced by the athlete. They display current wind speed readings to help athletes take performance decisions.
So in summary, anemometers, weather vanes, wind socks, Pitot tubes, anemographs and mobile apps are some instruments used to determine wind velocity. The choice depends on the purpose and degree of accuracy required.