3. Coriolis flow meter vs thermal flow meter
Coriolis flow meters allow the direct measurement of mass flows. Direct mass flow measurement eliminates inaccuracies caused by the physical properties of fluids. Thermal flow meters, on the other hand, allow indirect measurement of mass flows.
Due to the way of measuring, there are fundamental differences between the two kinds of devices, which influence their typical applications.
A thermal mass flow meter employs the fluid’s heat capacity to measure the mass flow rate. With a heater and one or two temperature sensors in the heart of the device, the applied power for heating (with one sensor) or the temperature difference between the two sensors is directly proportional to the fluid mass flow rate. Thermal mass flow meters are mainly used for gases.
Because the Coriolis principle directly measures the mass flow, Coriolis flow meters can be used for both gases and liquids.