Thermal Mass Flow Meters By Addmas Measurements

Thermal Mass Flowmeters
AT Thermal Mass Flowmeter is one of the most advanced flowmeter in gas mass monitoring. The sensor of AT Thermal Mass
Flowmeter is related to flow rate of the gas mass and meet the situation which the temperature and pressure is unstable
Principle of operation
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