American Meteorological Society Certification (AMS) Practice

The anemometer is a specialized instrument designed specifically for measuring wind speed. Typically, this device operates by using rotating cups or blades that respond to the wind's movement. The rate at which these cups or blades spin directly correlates to the speed of the wind, allowing meteorologists and researchers to quantify wind conditions accurately.

In contrast, other instruments listed serve different purposes. A barometer is utilized for measuring atmospheric pressure, which can provide indirect information about weather changes but does not measure wind speed. A thermometer is employed for measuring temperature, crucial for understanding environmental conditions but unrelated to wind measurement. Lastly, a hydrometer is used to gauge the density of liquids, typically in relation to water content, making it irrelevant in the context of measuring wind. Understanding the specific functions of these instruments clarifies why the anemometer stands out as the correct choice for measuring wind speed.