A rain gauge is a device used to measure the amount of rainfall in a given location over a period of time. A rain gauge is typically made of a glass cylinder that has an opening on top. The size of the opening is larger than the size of the glass cylinder at its base to allow the device to catch rainwater easily. The glass cylinder has measurement markings along its side, and is calibrated in millimeters or inches. The glass cylinder is mounted on a base that holds the cylinder in place.
A wind vane is used to tell the direction where the wind is coming from. It is typically made of a directional arrow that has a pointer on one end, and a tail on the other end. The directional arrow is mounted on a spindle with the axis of the spindle much closer to the pointer than to the tail of the arrow. The letters N, S, E and W are mounted at the spindle base and represent geographical locations (north, south, east and west). The directional arrow pivots as the wind blows, and points to the geographic location where the wind is coming from.
An anemometer measures wind velocity. A simple anemometer is made of four cups mounted symmetrically at the tip of four arms that converge on a single axis. The arms are mounted horizontally on a spindle that allows the cups to rotate around the axis as the cups catch the wind. The faster the wind speed, the faster the spindle rotates. The wind speed is measured by the number of revolutions per minute (RPM). The number of revolutions is recorded over a time period, and an average is determined.
Wind socks are simple devices that are typically made of textile shaped into a cone. The cone has a large opening at one end, and a small opening at the other end. The large opening is typically attached to a pole to allow the sock to catch the wind and indicate wind direction, and relative wind speed. Wind socks are a commonly located at airports, seaports and windy areas along highways. The wind sock points to the direction where the wind is blowing. A drooping wind sock indicates light wind, while one that sticks straight out horizontally indicates high wind speed.
