Thermal mass flow meter

We supply inline or insertion probe thermal dispersion flow meter for gas or air measurement. It is a perfect solution for gas or air measurement from small pipelines to large pipelines, ducts or stacks. It can take measurement of LPG,compressed air, CO2, biogas, natural gas, O2,BF gas (Blast furnace gas) ,combustion air, flare gas,He gas , Nitrogen gas and so on. Silver Automation Instruments supply different type thermal mass flow meters for various industrial gas applications, such as micro flow rate thermal mass flow meter, high temperature type, in-line type thermal flow sensor or insertion probe thermal mass flow meter.

Thermal mass flow meter Features

Direct mass or standard volumetric gas flow measurement, no temperature or pressure compensation required
Low end sensitivity, can detect gas leakage
Gas flow metering with low pressure drop
Low price cost gas or air mass flow measurement instrumentation
High accuracy gas flow meter, which can reach to 1% of reading, and 0.5% of full range
Easy to install the thermal mass flow sensor also thermal flow transmitter with easy to read user interface and parameter configurations
No moving parts and durable construction mass flow meter
Max bear temperature is 300℃,572°F, so it is a kind of high temperature gas flow meter
Thermal mass flow transmitters with different output, such as 4-20mA, pulse, also alarm switches output, it can even have Hart protocol, or Modbus RTU communication

How it works?

Thermal mass Flowmeters are designed to use the thermal properties of the fluid which is being measured. The typical industrial flow meter has two sensors one which is heated and another which remains unheated. This Device is accurately designed to measure the temperature of the fluid. It has a valve that allows the fluid to enter for it to be evaluated by the sensors. The heater sensor receives the heat but as heat increases some are lost in the flowing fluid However, the temperature measurements in the flow sensor take a record of this heat.

The fluid flow is determined by the heat input used by the transmitter and temperature measurements. Thermal dispersion flow meters are usually used in the gas flow because of their reliability and efficiency.

When determining the lost temperature emphasis is laid upon the thermal properties of the fluid and the design of the sensor. These variations can be facilitated by various temperature ranges and pressure changes. Therefore, it is very important to know the composition of the fluid so that proper and accurate measurements can be taken.

In most cases, thermal gas mass flow meter works best in a clean fluid which is free from impurities,such as air flow meter or compressed air flow meter. It is better to take the actual measurement of the fluid without necessarily mixing them up so that you can obtain accurate results. If the actual gas is not pure chances are that you will not get accurate measurements.


It has no moving parts which imply it requires less maintenance

which consequently lowers maintenance costs.

Thermal gas flow meter is also very reliable and accurate for applications that have fluctuating pressure and temperature.

It is highly accurate and it shows some consistency in repeatable measurements.

It has an impressive turndown ratio of 50:1

Thermal dispersion mass flow is good at measuring gases with low gas velocities

It also measures gas mass flow rate directly

From these advantages it is clear that is is a very reliable gas or air flow measuring instrument that requires users to be keen on detail if they want accurate readings. If you are looking for accuracy especially for pure gases then this is a perfect choice. On the other let us have a look at its limitations.


Relatively high initially costs

It is only limited to non -abrasive clean fluids so that it can take accurate measurements.

Inaccuracy can be caused as a result of variation from calibrated values. Therefore, it is vital to know the thermal properties of the fluid.

Perhaps, the flowmeter is very sensitive which requires pure and specific thermal properties. However, this limitation does not apply to automotive engines.

How to use Thermal Flowmeters

It is normally used for clean gases such as nitrogen, ammonia, helium and other pure industrial gases. Other mixtures like biogas can only be measured after determining their respective composition. The good thing is that it is entirely dependent on thermal properties. It can also be used in petrochemical plants so long as the thermal properties of the gas are known. Some corrosive gases such as by sulfide can only be measured after determining its composition properties. This is quite an impressive system for those users who can measure pure gases because you are guaranteed accuracy in the values.


This instrument is very reliable in mass flow measurements. The following are common applications.

Landfill gas recovery

The gas leak testing and detection

Gas flow mixing and blending

Flare gas measurement,flare gas flow meter

Natural gas consumption for boiler feed control and burners,natural gas flow meter

Compressed air flow and distribution.

It is also used in industries such as pulp and paper, metals and mining, water and waste, food and beverage, chemical, power, gas, and oil.

Application Cautions for Thermal Flowmeters

Non-abrasive fluids and those that are capable of coating the sensor can adversely affect the flow measurement. The sensor will have to be regularly cleaned which will increase its maintenance costs. Additionally, if the components vary from the calibrated values it can make the device to be highly inaccurate. It is not suitable for fluid which has varying compositions. Gases with droplets and aerosols also compromise the functionality of thermal flow meter because they require large energy to heat up.

Therefore, when using this device it is important to stick to known specifications so that it can work optimally. Ensure the purity of the fluids is always maintained to avoid inaccuracy. This will help in accurately calculating the mass flow rate. Some industries require precise accuracy so that it can help in the management and monitor of its systems.