An anemometer is an instrument which is used to measure wind speed mostly found in weather station tools. Wind is moving air in motion and is caused by difference in air pressure. The device name is originated from a Greek word anemos, meaning wind – that has been used to explain any wind speed instrument.
In the case of traditional anemometer which has four cups to measure the speed of wind while each of them are attached to the horizontal arm. The faster the wind, the faster the cups spin the axis. Revolutions per minute (rpm) are the wind speed measurement and indicate the speed of the cups revolving. Wind speed measurements help in weather forecasting particularly forecasting of hurricanes, storms and tornadoes. Today, modern anemometers have unique look and even others pocket-size devices.
Types of Anemometers
There are a number of anemometers used to measure the wind speed. Basically, anemometers can be categorized in two broad categories, namely portable handheld anemometers and those build and affixed to the ground at weather stations. Most portable handheld anemometers are digital anemometers. These two broad categories are further categorized into individual types that includes cup anemometers, hot wire anemometers, ultrasonic anemometers, pressure tube anemometers, windmill anemometers, laser Doppler anemometers among others. Below is a brief explanation about each of the mentioned type of anemometer.
Cup anemometer – it is also known as rotational anemometer and it has cups placed onto a vertical axis and when the wind presses against them, this causes the cups to rotate around. The wind speed is determined by how faster the cups rotate. This type of anemometer is used by educational institutions, researchers and meteorologists.
Hot wire/thermal flow anemometers – measures both the wind speed and pressure. Commonly found at businesses for purposes of heating, ventilating and air conditioning.
Ultrasonic anemometers – this type of anemometer has four sensors arranged in a square pattern.
Pressure tube anemometer – It is also called wind sock. This instrument provides wind direction and wind speed by who higher the tube rises off the ground. Mostly found around airports.
Windmill anemometer – it measures both wind speed and direction. The device has a propeller attached on its front side and a large tail at the backside. It doesn’t have a wind speed meter but how fast the propeller rotates indicates the speed of the wind.
Laser Doppler – this anemometer utilizes the Doppler effect to determine the flow of moving air. Commonly used in river hydrology.
Most handheld anemometers are waterproof, others can even float and allows the use to access a variety of wind speed measurement units. The digital handheld anemometers have wind meters which can be connected to iPhones and Android smartphones through Bluetooth. For example, a FixKit Handheld Digital Anemometer measures wind speed in 7 user-selectable units. Other characteristics include large, easy to read screen, wind speed meter is detached from display unit etc.
On conclusion, anemometers have a variety of uses in day-to-day life. The devices are used in weather stations to measure wind speed which helps indicating a change in weather patterns for meteorologists, such as hurricanes, storms and tornadoes. This information is important for engineers, pilots, and climatologists and physicists for studying movement of air.