A thermal anemometer is a device used to measure the speed of air or gas flow. It operates on the principle of heat transfer, where a heated element cools down as air passes over it. The rate of cooling is proportional to the flow velocity, allowing for accurate measurements. These instruments are commonly used in various applications, including meteorology, HVAC systems, and industrial processes. They can provide real-time data and are valued for their sensitivity and precision in detecting low flow rates.