Thermal Mass Flow Meter Working Principle

Many mass flow controllers mfc which combine a mass flow meter electronics and a valve are.

Thermal mass flow meter working principle.

Thermal mass flow meters also known as thermal dispersion or immersible mass flow meters comprise a family of instruments for the measurement of the total mass flow rate of a fluid primarily gases flowing through closed conduits a second type is the capillary tube type of thermal mass flow meter. Vortex flow meters are ideal for steam flow measurement because other mass flow meters or volumetric flow meters cannot measure steam. In a typical thermal flow meter gas flowing over a source of heat absorbs the heat and cools the source. Thermal mass flow working principle theory and design.

Thermal mass flow meters employ the thermal dispersion principle whereby the rate of heat absorbed by a fluid flowing in a pipe or duct is directly proportional to its mass flow. Volumetric measurements are affected by all ambient and process conditions that influence unit volume or indirectly affect pressure drop while mass flow measurement is unaffected by changes in viscosity. No temperature and pressure compensation is required. Industrial thermal mass flow meters also known as thermal dispersion or immersible thermal mass flowmeters comprise a family of instruments for precision measurement of total mass flow rate equation of a fluid primarily gases flowing.

As flow increases more heat is absorbed by the gas. Volumetric measurements are affected by all ambient and process conditions that influence unit volume or indirectly affect pressure drop while mass flow measurement is unaffected by changes in viscosity density temperature or pressure. The instrument uses the constant temperature difference method to accurately measure the gas. Gas flows by the heated flow sensor and molecules of the gas transport heat away the sensor cools and energy is lost.

The thermal mass meter measures gas flow based on the concept of convective heat transfer. Differential pressure techniques can be used for indirect mass flow measurement of steam but as mentioned above direct mass flow measurements are much better than indirect mass flow measurement. Thermal mass flow meter is a true mass flow meter. Thermal mass flow sensors measure the mass flowrate of gases and liquids directly.

Thermal gas mass flow meters are designed based on the principle of thermal diffusion.