N2 Mass Flow Controller

In industrial production, nitrogen (N2) is one of the most commonly used protective gases, purge gases, and carrier gases. To achieve precise, stable, and reproducible nitrogen usage, a Nitrogen Mass Flow Controller (N2 MFC) is required.

Here you will quickly understand its purpose, principles, and key parameters, making it easier for you to choose a correct N2 mass flow controller.

Where is N2 mass flow controllers commonly used?

• Nitrogen mass flow controllers are widely used in the following situations:

• Semiconductor and Photovoltaic Industry: Precise Control of Nitrogen Flow in Thin Film Deposition (CVD/PVD), Diffusion Furnace, Etching, and Annealing Processes

• Laser cutting and laser welding: as an auxiliary gas, controlling the stability of nitrogen flow directly affects the quality of the cutting section

• Food packaging (MAP modified atmosphere packaging): precise ratio of nitrogen filling in the packaging machine

• Lithium battery production: nitrogen supply for cell drying room and injection workshop

• Heat treatment furnace: control of the mixing ratio of nitrogen, hydrogen, and argon in controlled atmosphere heat treatment

• Laboratory and analytical instruments: carrier gas and purge gas for gas chromatography (GC) and mass spectrometer

• Chemical reactor: Inert gas protection and displacement of reaction kettle

• 3D printing (metal additive manufacturing): maintenance of nitrogen atmosphere in the forming chamber

 If your process requires a nitrogen flow rate that is "repeatable and not affected by temperature and pressure fluctuations", then a mass flow controller is more suitable than traditional rotor flow meters and float flow meters.

Working principle of N2 mass flow controller

The mainstream N2 mass flow controller adopts the thermal principle (capillary thermal diffusion).

Simply put, the working process involves a small amount of nitrogen flowing through the sensor capillary tube, which is wrapped with two sets of heating resistance wires. When gas flows, it takes away heat, causing a change in the temperature difference between the upstream and downstream resistors, which is proportional to the mass flow rate. The controller compares the sensor signal with the set value, and then drives the electromagnetic proportional valve to adjust the opening until the actual flow rate is equal to the set flow rate.

The advantages of the thermal principle are:

• Directly measure mass flow rate (in sccm, slm, kg/h) without the need for additional temperature and pressure compensation

• Wide range ratio, precise control even for small flow rates

• Fast response, usually stable within 1-2 seconds

 This is also the biggest difference between it and a "volumetric flowmeter" - the mass flow rate will not drift due to changes in on-site temperature and pressure.

Main technical parameters of N2 mass flow controllers

 When selecting, it is recommended to provide the following information to facilitate our recommendation of suitable models:

•  Your actual application

• Actual maximum and minimum flow range

• Inlet pressure and outlet back pressure

• Gas purity (ordinary nitrogen or high-purity nitrogen)

• Do you need a communication interface (PLC docking)

• Interface size and installation method

Do you need a quotation or technical consultation for N2 mass flow controller?

Silverinstruments.com provide N2 mass flow controllers with multiple ranges and interfaces, supporting non-standard customization, stable delivery time, and rich export experience, covering markets such as Southeast Asia, the Middle East, Latin America, and Oceania.

If you are working on project selection or want to compare prices and delivery times, please feel free to leave a message below or send us an email directly:

 We will reply within 12 hours and provide detailed product specifications (PDF) and quotation.