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.
Wind has both speed and direction. Anemometers measure wind speed and wind vanes measure wind direction. A typical wind vane has a pointer in front and fins in back. When the wind is blowing, the wind vane points into the wind. For example, in a north wind, the wind vane points northward. A cup anemometer is a common tool to measure wind speed. The cups catch the wind and produce pressure difference inside and outside the cup. The pressure difference, along with the force of the wind, causes the cups to rotate.