Thermal Mass Flow Meter Technology

inline thermal mass flow meters factory supply

Best Technology Guide to Thermal Mass Flow Meters.

A thermal mass flow meter (TMF) is a flow meter designed based on the principle of thermal diffusion or heat conduction. It directly measures the mass flow of gas without additional temperature and pressure compensation.

The thermal mass flow meter is the preferred gas flow meter in industrial processes. Such as nitrogen, compressed air, natural gas, hydrogen, etc.

Sino-Inst is a professional manufacturer of thermal gas mass flowmeters. We provide thermal mass flowmeters covering DN10~DN4000. Based on many years of experience in gas measurement and control services, we are here to share with you the advantages, principles, applications, etc. of thermal mass flowmeters. We hope it will help you choose the right gas flowmeter.

Featured Thermal Mass Flow Meters

Insertion type thermal mass flow meter — SI-3502 Air Mass Flow Meter

Thermal gas mass flow meter — SI-3503 Gas Mass Flow Meter

DC-S030 series digital communication thermal gas mass flow controller — DC-S030 Series Digital Communication Thermal Gas Mass Flow Controller / Mass Flow Meter

AC-S030 Micro-range Mass Flow Controller-Flowmeter — AC-S030 Micro-range Mass Flow Controller/Flowmeter

DC-B1000 Series Large-Range Gas Flow Controller.png — DC-B1000 Series Large-Range Gas Flow Controller

DC-M500 Digital Gas Mass Flow Controller/Flow Meter

DC-M100 Digital Flow Controller-Flow Meter — DC-M100 Digital Flow Controller/Flow Meter

How Does a Thermal Mass Flow Meter Work?

What is a Thermal Mass Flow Meter?

A thermal mass flow meter is a flow meter that measures the mass flow of a fluid.

A thermal mass flow meter measures the mass flow of a fluid by using the temperature field changes that occur when the fluid flows through a pipe heated by an external heat source, or by using the relationship between the energy required to increase the temperature of the fluid when the fluid is heated and the mass of the fluid.

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Theory of Operation

A thermal gas mass flowmeter is a meter that measures the mass flow of gas using the principle of heat conduction. The sensor of the thermal mass flowmeter consists of two reference thermal resistors (platinum RTD). One is the mass speed sensor T1, and the other is the temperature sensor T2 that measures the temperature change of the gas.

When these two RTDs are placed in the measured gas, the sensor T1 is heated to a constant temperature difference above the gas temperature, and the other sensor T2 is used to sense the temperature of the measured gas.

As the mass flow rate of the gas increases, the airflow takes away more heat, and the temperature of the sensor T1 decreases. To maintain a constant temperature difference between T1 and T2, the heating power of T1 must increase.

According to King’s law of thermal effects, there is a certain mathematical relationship between heating power P, temperature difference △ T (T1-T2) and mass flow Q.

P / △ T = K1 + K2 f (Q) K3

K1, K2, K3 are constants related to the physical properties of the gas.

Specifications of Thermal Mass Flow Meters

Medium	All gases (except acetylene)
Pipe diameter	DN10-80 (Flange type)			DN100-6000 (Insert type)		Split type (support customized)
Flow rate	0.5-100m/s
Accuracy	Compact type: 4-line LCD display
Operating temp.	Sensor		Default type: -10~+200℃
			High temp. type: -10~350℃
	Transmitter		-20~+45℃
Operating pressure	Medium pressure≤10MPa				Medium pressure≤2.5MPa
Power supply	Compact type			DC24V or AC220V≤18W
	Remote type			AC220V≤19W
Response time	1s
Output	4-20mA	Optical isolation, max. load 500Ω
	RS485	Optical isolation
	HART
Pipe material	Carbon steel, stainless steel, plastic, etc.
Display	Compact type: 4 lines LCD display
Display content	Mass flow, standard volume flow, accumulated flow, time, accumulated time, medium temp., standard flow, etc.
Ingress protection	IP67 (sensor part)
Sensor material	Stainless steel			Stainless / carbon steel

Benefits of Thermal Mass Flow Meters

Constant temperature heating design, direct mass flow measurement.
No need for pressure/temperature transmitter.
All products are designed with no moving parts.
Wide range ratio:100:1 is sensitive to flow.
Low pressure loss.
Suitable for all types of single or mixed gas flow measurement.
The measurement results of thermal gas mass flowmeter are not affected by fluid properties (such as temperature, pressure, humidity, composition, etc.).

Thermal Mass Flow Meter Advantages and Disadvantages

Advantages	Disadvantages
Directly measure mass flow without temperature and pressure compensation.	Thermal mass flowmeter responds slowly.
Fast response speed, can reflect flow changes in real time.	High requirements for flow field, need to maintain a stable flow field to obtain accurate measurement results.
Wide measurement range, suitable for a variety of gases and flow ranges.	Requirements for pipeline materials, need to have good thermal conductivity.
Good stability and long service life.	Pulsating flow will be limited in use.
No moving parts, no obstructions, small pressure loss.	Thermal mass flowmeter for liquids is also limited in use for viscous liquids.

Thermal Mass Flow Meter Applications

Measurement of oxygen, nitrogen, hydrogen, chlorine and multi-component gases.
Measurement of blast furnace gas and coke oven gas.
Flue gas measurement.
Aeration and chlorine measurement in biogas and water treatment.
Compressed air measurement.
Flow measurement of natural gas, liquefied gas, flare gas, etc.
Primary and secondary air flow measurement of power plant blast furnace
Flow measurement of underground ventilation or exhaust system.

Based on our many years of experience in gas measurement services. We have compiled and summarized the media suitable for thermal mass flow meters for your reference:

Gases Commonly Measured with Thermal Mass Flow Meters:

Oxygen (O2)
Nitrogen (N2)
Carbon dioxide (CO2)
Hydrogen (H2)
Chlorine gas,
Argon (Ar)
Helium (He)
Natural gas,
Liquefied gas,
Compressed air
Multi-component gas measurement of biogas,
Methane (CH4)
Aeration and chlorine measurement in water treatment,
Gases,
Carbon dioxide gas flow rate during beer production,
Gas flow during the semiconductor chip manufacturing process,
Gas flow measurement in solvent recovery systems
Blast furnace gas,
Coke oven gas,
Flue gas,
During the gas process, air,
Calcining furnace flue gas,
Combustion gas measurement in coal-fired boilers.
Smoke flow (speed) measurement of smoked meat (CEMS)
Primary air, secondary air,
Mine ventilation or exhaust system flow,
Gas flow (velocity) measurement in heating, ventilation, and air conditioning systems
And many more… (Comments are welcome to add)

If you are not sure whether you can choose a thermal mass flowmeter for your measurement conditions, please feel free to contact our Sino-Inst technical engineers!

Our Advanced Service Solutions for Thermal Mass Flowmeters

Inline Compressed Air Flow

A Compressed Air Flow Meter is a digital flow meter that works for the air compressor. Thermal mass, vortex, and DP flowmeters are common gas flow sensors.

Air consumption is an important info for industrial inline gas flow pipes. Compressed air is the most expensive form of energy in manufacturing plants. And compressed air accounts for up to 20% of the overall energy costs.

So, It is important to measure compressed air flows precisely in all conditions. This can improve the energy efficiency of compressed air systems while reducing costs.

Natural Gas Flow

Natural gas flowmeter is an online flowmeter used in natural gas pipelines. For example: thermal mass flowmeter, ultrasonic natural gas flowmeter, natural gas turbine flowmeter, intelligent gas vortex flowmeter and differential pressure flowmeter. These are the most common online natural gas flowmeters with digital display.

Choose a suitable natural gas flowmeter according to the measurement conditions of the natural gas pipeline. For example: pressure, temperature, straight pipe length, pipe diameter, insertion or remote installation, etc. If you have any questions about natural gas flowmeter, please contact us.

Thermal Mass Flow Meter Price

Sino-Inst is a manufacturer of thermal mass flow meters. We offer a variety of mass flow meter products and a full range of consulting services for flow measurement solutions, instrumentation, sub-assembly, design and fabrication, engineering, calibration and certification.

Thermal mass flow meter price is decided by your measurement details. Please offer your information like:

Measurement medium:
Pipe caliber:
Measure temperature:
Measure pressure:
Installation method:
output signal:
Material requirements:

All these parameters will affect the price. But we will surely offer you the best price.

Difference Between Thermal Mass Flowmeter and Vortex

inline thermal mass flow meters split type

A vortex flowmeter is a volume flowmeter. A thermal gas flowmeter is a mass flowmeter. The measurement principles of the two are different.

Vortex flowmeter is widely used and can measure gas, liquid, and steam. A thermal flowmeter can only measure gas.

A vortex flowmeter is much cheaper.

A vortex flowmeter has requirements for the installation of the straight section of the measuring pipeline, usually 10D in front and 5D in the back. The thermal mass flowmeter has no restrictions.

More about Vortex Flow meters

Difference Between a Thermal Mass Flow Meter and a Mass Flow Meter

What is the difference between a thermal mass flow meter and a mass flow meter?

The thermal method is only applicable to gases. It uses the different ways in which different gases conduct and absorb heat to measure the heat transfer or heat loss from heating to induction, thereby obtaining the corresponding flow rate.

A common mass flowmeter refers to a Coriolis flowmeter. The Coriolis flowmeter uses the Coriolis principle (the interference of the Earth’s rotation on the curved motion of matter) to directly measure the mass of the fluid flowing through, and can measure gases and liquids.

More about Coriolis Mass Flow Meters

Technical Support

Thermal mass flow meters measure a flow rate based on convective heat transfer. Fluid properties are some of the many factors that influence convection. Each gas has unique properties, which is why these flow meters are calibrated for a specific application. You wouldn’t want a meter calibrated for an air application placed into a natural gas application without recalibration or some type of field adjustment if applicable.

Thermal flow meters are at the forefront in flow measurement for emissions reporting and energy management projects. Some popular applications include monitoring gas fuel flow to a combustion source to report SO2 emissions, stack gas flow in power plants as part of a continuous emissions monitoring (CEM) system of NOX and SO2 and flares in a gas field that need to be reported to environmental authorities. These applications prove difficult for many flow meter technologies.

The thermal flow switch is designed based on the principle that the temperature change of the probe generates a temperature difference. The probe has a built-in thermal sensor and two thermal sensors in contact with the medium.

When the thermal flow switch is working, the heating sensor emits a constant amount of heat. When there is no medium flowing in the pipeline, the heat received by the thermal sensor is a constant value. When there is medium flowing, the heat received by the thermal sensor will change with the flow rate of the medium, and the thermal sensor converts the temperature difference signal into an electrical signal. When the flow rate reaches a certain set value, the thermal flow switch outputs a switch signal.