Anemometer is a type of weather instrument that are used for measuring the wind speed. The device is absolutely necessary for measuring the wind energy. The direction of the wind and its velocity is also measured by the anemometer which helps the meteorologists in detecting the natural disasters caused by wind.

The anemometers are broadly divided into two categories:

• Pressure Anemometers
• Velocity Anemometers

As the name suggests, one measures the pressure of the wind and the other the velocity. Modern technology allows the instruments to provide both the measurements. The pressure and velocity anemometers are further sub divided into the following categories:

Pressure Anemometers

•  Cup anemometers: This is an anemometer with a vertical axis and three cups for capturing the wind. The number of revolutions of the cups per minute is registered electronically. The wind speed is directly proportional to the rate of the rotation of the cups and thus is the wind speed measured.

•  Windmill anemometers

•  Hot-wire anemometers

•  Laser Doppler anemometers: The wind velocity is measured through a beam of laser light. The speed of the air molecule in front of the beam of light is calculated to measure the wind speed.

•  Sonic anemometers: The velocity of the wind is measured through ultra sonic sound effects in this weather instrument.

Velocity Anemometers

•  Plate anemometers

•  Tube anemometers

There are also Ultrasonic Anemometers or laser anemometers through which the meteorologists can detect the shifting of sound. The hot wire anemometers can depict the wind speed.