Mass Flow Meters

Thermal sensor consists of two sensing elements - a velocity sensor and a temperature sensor that automatically corrects for changes in gas temperature(figure1). The transducer electronics heats the velocity sensor to a constant temperature differential above the gas temperature and measures the cooling effect of the gas flow. The electrical power required to maintain a constant temperature differential is directly proportional to the gas mass flow rate.
In order to keep the stable temperature between Ts and Ta, circuit should be provided higher power. The range of power is related to the mass flow rate of liquid. Through test the output of power can get the mass flow rate. Furthermore, the heat on the heated velocity sensor bring by the move of gasses not cause the heat exchange. So this kind of flowmeter can measure all kinds of gases. The table of AT Series Thermal Mass Flowmeter please see figure.