Thermal flow sensors are a type of flowmeter that measures the flow rate of gases or liquids based on the principles of heat transfer.

These sensors use a heated element and one or more temperature sensors. As the fluid flows past the heated element, it draws heat away, causing a temperature change that is directly proportional to the fluid's mass flow or velocity. A key advantage of this technology is that it has no moving parts, making the sensors highly reliable and ideal for measuring very low flow rates.