Certified Safety Professional Practice Exam

The type of anemometer that measures airflow based on heat removal from the air is the thermal anemometer. This device operates on the principle of heat transfer: it uses a heated sensing element whose temperature decreases as air passes over it. The airflow cools the sensor, and the rate of cooling is proportional to the velocity of the air. By measuring the temperature drop, the thermal anemometer can accurately calculate airflow rates. This principle allows for precise measurements, making thermal anemometers particularly useful in applications where small changes in air velocity need to be detected.

In contrast, the other types of anemometers function on different principles. For instance, a rotating vane anemometer measures airflow by the rotation of a vane that is moved by the wind; the speed of the rotation correlates to the wind speed. A Pitot tube, typically used in aerodynamics, measures fluid flow velocity by converting dynamic pressure into a fluid flow measurement. Lastly, a centrifugal anemometer employs the dynamics of centrifugal force to gauge airflow, which is a fundamentally different method than heat transfer.