How does a mass flow controller work?

sales01@cxflowmeter.com

Mass flow controllers can be used to control a variety of clean and dry gases, including corrosive and special gases, but the use of corrosive 

and special gases requires the correct selection of models and sealing materials. When ordering, the user should contact the supplier to make

 special instructions when using the gas, so as to avoid serious losses due to wrong selection or sealing material. Generally, the material that

 the mass flow control brake contacts with the working gas is 316L stainless steel, and the sealing material is divided into metal welding, PTFE

 and ordinary fluorine rubber glue. MFCs with metal welded seals for mass flow controllers can in principle be used for any gas, including 

various corrosive and special gases. For highly corrosive gases such as boron tribromide, boron trichloride, hydrogen fluoride and gold used in

 MOCVD

The oxidizing gas is recommended to use a metal-welded sealed MFC.

The mass flow controller is composed of a flow sensor, a shunt channel, a flow regulating valve, an amplifying controller, etc.

The sensor of the mass flow controller uses the principle of capillary heat transfer thermocalorimetry to measure the mass flow of gas (without 

temperature and pressure compensation). The flow signal measured by the sensor heating bridge is sent to the amplifier for amplification, the 

amplified flow detection voltage and the set value are compared with the voltage, and then the difference signal is amplified to control the 

regulating valve. The closed loop controls the flow through the channel to be equal to the set consistent flow. The diverter determines the flow

 of the main channel. The flow indicator matched with the mass flow controller has a voltage regulator power supply, digital voltmeter, setting 

potentiometer, peripheral equipment, built-in conversion and three-position valve control switch, etc.

Mass flow controllers can easily and accurately monitor the flow in pipelines without temperature and pressure compensation. Various gas and

 thermal gas mass flow meters are a new type of flow measurement and monitoring instruments.

The mass flow controller adopts the principle of thermal diffusion, and the thermal diffusion technology has excellent performance and high 

reliability under harsh conditions. Its typical sensing element consists of two thermal resistances (platinum RTDs), one is a speed sensor and the

 other is a self-compensating gas

Temperature sensor for body temperature changes. When both RTDs are placed in the medium, the speed sensor is heated to ambient 

temperature and the other temperature sensor is used to sense the medium temperature. The gas flow through the velocity sensor is calculated

 from the heat transfer from the sensing element. As the gas flow rate increases, the heat carried away by the medium increases. The

 temperature of the sensing filter decreases. To keep the temperature constant, it is necessary to increase the operating current of the mass

 flow controller. The current applied is proportional to the flow rate of the medium.

Mass flow controllers are instruments that measure fluid flow using the principle of heat conduction. The mass flow controller uses the

 constant temperature difference method to accurately measure the gas mass flow. The mass flow controller is small in size, high in digitization, 

and easy to install. The quantity is accurate. Mass flow controllers can be used in actual working conditions of hydrocarbon gas, combustible 

gas and smoke in industrial enterprises such as glass, solar energy, atmospheric monitoring, petroleum and petrochemical, industrial

 production, coal gas pipeline distribution control, carbon metallurgy, gas production and distribution, environmental protection and other 

industrial enterprises Measurement and monitoring of mass flow or volume flow of lower channel gas.

If you want to know more parameters and quotation of liquid gas mass flow controller, please contact winny: sales01@cxflowmeter.com