What type of flow meter cools as heat is removed during fluid flow?

The type of flow meter that cools as heat is removed during fluid flow is the thermal mass flow meter. These devices operate based on the principle of heat transfer. In a thermal mass flow meter, a heated element is placed in the flow path of the fluid. As the fluid flows over the heated element, it removes heat from it. The amount of heat removed from the sensor is proportional to the mass flow rate of the fluid.

This cooling effect results in a change in temperature that can be measured. A control system then uses this temperature change to determine the flow rate of the fluid accurately. This makes thermal mass flow meters particularly effective for measuring gases, where the flow rate can be directly correlated to the heat absorbed by the flowing medium.

While pressure instruments, velocity instruments, and positive displacement instruments are all vital in various applications for measuring flow, they operate based on different principles and do not utilize the heat transfer concept that is critical in thermal mass flow measurement.