What is the name of the instrument that measures wind speed?

The instrument that measures wind speed is known as an anemometer. Anemometers are designed to capture the velocity of air as it moves, often using rotating cups or blades that spin in response to the wind. As the wind blows, it forces the cups or blades to turn, and the speed at which they rotate is directly correlated with the wind's speed.

Anemometers are widely used in meteorology, aviation, and various engineering applications to gather vital data about wind conditions, which is essential for weather forecasting, climate studies, and the design of structures that might be affected by wind forces.

On the other hand, a barometer measures atmospheric pressure, a pyranometer measures solar radiation, and a potentiometer measures electric potential (voltage). Thus, while these instruments serve important functions in their respective fields, they do not measure wind speed like an anemometer does.