Thermal Mass
Thermal Mass Meters – Principle of Operation
​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. In a typical thermal mass flow meter, gas flowing over a source of heat absorbs the heat and cools the source. As flow increases, more heat is absorbed by the gas.
​The amount of heat dissipated from the heat source is proportional to the gas mass flow and its thermal properties. Therefore, measurement of the heat transfer supplies data from which a mass flow rate may be calculated.
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These flow meters are designed to accurately monitor and measure mass flow (as opposed to measuring volumetric flow) of clean gases, a parameter that is not temperature dependent. Therefore, the thermal mass flow meter does not require a correction for changes in gas temperature, pressure, viscosity and density.
View our range of thermal mass flow meters.
Thermal Mass Flow Meter Advantages
- Measure gas mass flow rate directly
- Suitable for applications where temperature and pressures fluctuate
- Highly accurate and repeatable measurements with a typical accuracy of ± 1% FS
- Able to measure accurately low gas flow rates or low gas velocities
- Excellent turn down ratio, typically 50:1
- No moving parts
Thermal Mass Flow Meter Limitations
- Gas mass meter use is limited to clean, non abrasive fluids
- Presence of moisture or droplets can lead to measurement inaccuracy
- Thermal properties must be known: variation from calibrated values can cause inaccuracies
- Relatively high initial cost
They are suitable for a variety of processes requiring mass flow measurement and are frequently used for the regulation of low gas flows. Some common gas flow applications for thermal mass flow meters include
- Compressed air flow and distribution
- Natural gas consumption eg for burner and boiler feed control
- Monitoring and control of stack or flue gas (where composition known)
- Landfill gas recovery
- Flare gas measurement
- Gas flow mixing & blending
- Gas leak testing and detection
We offer a wide range of thermal mass flow meters including Compact or SMART with or without ATEX approval.
Need Advice About Thermal Mass Flow Meters?
iCenta is a instrumentation and control solution specialist with experience in control technologies for diverse applications, fluid types and process conditions. Call iCenta now for advice, sales & technical information on 01722 439 880.