Anemometer
Topic: Atmospheric Pressure, Winds and General Circulation · NCERT: Class 7, Ch 2 "Understanding the Weather"
Meaning
An anemometer is an instrument that measures wind speed. The common type has three or four small cups on arms that turn around a vertical rod. The stronger the wind, the faster the cups spin. A meter turns the number of spins into a speed, in kilometres per hour or in knots. Weather offices need this reading to warn people about storms.
Example
When a cyclone nears the Odisha coast, anemometers at coastal weather stations show wind speed climbing hour by hour. This helps forecasters decide when to warn fishermen and move people to safety.
Don't confuse with
- Wind vane: this shows wind direction, not speed.
- Beaufort scale: this grades wind strength by what it does to things around us, such as swaying trees or rough waves. No instrument is needed.