How Much Do Diamond Engagement Rings Cost. There are two major factors which contribute to the cost of a diamond: a ratings system called the âFour Csâ and whether or not the diamond is ASG/GIA certified. The Four Cs refers to the diamondâs color, cut, clarity, and carat size.
Best Answer: A wind vane is used to tell wind direction. The National Weather Service and those that have a lot of money use a Aerovane. Aerovanes are commonly used at many weather stations and airports to measure both wind direction and speed.
The measurement of wind speed is usually done using a cup or propeller anemometer, which is an instrument with three cups or propellers on a vertical axis. The force of the wind causes the cups or propellers to spin. Wind direction is measured by a wind vane that aligns itself with the direction of the wind.