Plate anemometers measure wind pressure and consist of a suspended plate that is deflected by the wind. The variations in movement translate into electrical signals which show variation in pressure. Another form is a pitot-tube anemometer, a U-shaped glass tube containing some liquid. One end has an open tip that points into the wind. The other end points upward. Like a barometer, the stronger the wind pressure, the more the liquid rises in the tube, indicating rising pressure.
The simplest and most recognizable form of wind speed anemometer are the cup variety. Four cups spin on a vertical axis aligning to the wind direction, moving with it. Spinning cups translates into electrical signals giving the wind speed. Other more developed designs spin on three proportional arms. A windsock is attached to this form of anemometer to furnish the wind direction data. Other anemometers are propeller types, driven by the wind, facing parallel to the wind with a wind vane attached. A third type derives wind speed from the wind chill factor by using a heated wire, gauging the amount of energy required to maintain a temperature at that level. These can also be used for natural gas applications. Split laser beams and ultrasonic sound waves are frequently used in commercial weather stations.
A vane anemometer on the steeple of a church in the center of European towns was the weather prediction method for centuries. Today, amateur metereologists have wireless electronic anemometers in their backyards. Industrial applications for anemometers include re-vegetation projects, projects taken on by NASA, research into shipboard wind speed, and measurements of the wind velocity on Venus. Measurements from thousands of anemometers feed into computers at NOAA and The Weather Channel to bring us highly accurate predictions of upcoming weather patterns. Also, anemometers are found at airfields all over where their measurements are an integral part of take-offs and landings and also on ships as part of the ship's instrumentation system. Other applications are wind-tunnels and gas pipe technology. Sonic or ultrasonic anemometers, calibrated in a wind tunnel, and containing no moving parts, are really useful for measuring weather conditions that are very turbulent.
The anenometers of the future will probably be more developed versions of the most robust instruments being used today. With the development of highly portable and modular units, it is not difficult to see monolithic electronic versions being developed connecting an LSI chip to a single sensor. Certainly the concept of a measuring device being inserted into the damage pattern of a highly violent tornado will become reality, and an integral part of the new breed of neolithic intelligent anemometers emerging to furnish the world's weather prediction and other wind measurement needs.