How to measure the wind speed and its direction?

Speed Measurement
The wind speed is measured with an instrument called an Anemometer, most commonly used for the measurement of near-horizontal wind speed.

This instrument consists of a cup assembly (three or four cups) centrally connected to a vertical shaft for rotation. At least one cup always faces the oncoming wind. The aerodynamic shape of the cups converts wind force to rotational torque. The cup rotation is nearly linearly proportional to the wind speed over a specified range.

A transducer in the anemometer converts this rotational movement into an electrical signal, which is sent through a wire to a data logger or recorder to display the measured speed.

Direction Identification
A wind vane is used to measure wind direction. The most familiar type uses a fin connected to a vertical shaft. The vane constantly seeks a position of force equilibrium by aligning itself with the wind. Most wind vanes use a potentiometer-type transducer that outputs an electrical signal relative to the position of the vane.

This electrical signal is transmitted via wire to a data logger to display and relates the vane’s position to a known reference point (usually true north). Therefore, the alignment (or orientation) of the wind vane to a specified reference point is important.