When choosing a nitrogen flow meter, it is necessary to select the appropriate type based on specific operating conditions (such as pipe diameter, flow rate, accuracy requirements, medium state, etc.). Here are several types of flow meters commonly used for measuring nitrogen and their characteristics:
1.Thermal gas mass flowmeter
This type of flowmeter is based on the principle of thermal diffusion. It directly measures the mass flow rate of gas using the constant temperature difference method, without the need for temperature and pressure compensation.
Features: High sensitivity, extremely low pressure loss, fast response speed, no requirements for installation direction.
Application scenarios: Particularly suitable for precise measurement of small diameters and small flow rates (such as DN8 to DN32 pipes, from micro to hundreds of liters per minute). Widely used in semiconductor, photovoltaic, medical (such as ventilators), laboratory analysis, and industrial process control for nitrogen metering.
Representative product: The thermal gas flowmeter from Angji Instrumentation, which is specifically designed for nitrogen (N2) measurement, features high repeatability and high measurement dynamics.
2. Rotating Vortex Flowmeter
Working principle: When nitrogen enters the flowmeter, the spiral-shaped blades force the fluid to undergo rotational motion, generating vortex flow. The rotational frequency of the vortex flow is proportional to the flow velocity of the medium. By detecting this frequency, the flow rate can be calculated.
Core Strengths:
Stronger low-flow measurement capability: Its flow measurement lower limit is lower, and the range ratio is wider. In working conditions where the flow at the customer site is small or fluctuates greatly, it can ensure more accurate measurement.
High integration: The intelligent instrument integrates a flow probe, a microprocessor, as well as pressure and temperature sensors. It can automatically and real-time track compensation and correction for compression factors, and directly display the standard volume flow rate.
Installation is flexible: It has no moving mechanical parts, is corrosion-resistant, and the dial head can rotate, allowing for installation at any angle.
Applicable scenarios: Particularly suitable for nitrogen measurement scenarios with moderate flow rates, significant flow fluctuations, or high requirements for low flow measurement.
3. Vortex Flow Meter
Working Principle: Based on the Karman vortex street phenomenon, a cylindrical obstruction is vertically inserted into the fluid pipeline. The fluid generates alternating vortices (Karman vortex street) behind it. The frequency of vortex separation is linearly related to the flow velocity of the fluid, and this is used to calculate the flow rate.
Core Strengths:
Resistant to harsh conditions: Excellent heat resistance and vibration resistance properties. Some models can operate stably in environments with temperatures up to 350℃ and strong vibrations.
Good versatility of the medium: Besides nitrogen, it can also be widely used for measuring various gases and liquids such as steam, compressed air, and natural gas.
Long-term stability is excellent: no zero-point drift, a lifetime-effective K coefficient, and low maintenance requirements.
Application scenario: Suitable for nitrogen measurement in medium to high flow rates, large pipe diameters, high temperature and high pressure conditions, or in situations with particularly demanding working conditions.
Selection Suggestions
When making the actual selection, it is necessary to match it with your specific working conditions:
Consider the flow range: If the commonly used flow rate at the site is small or the flow rate fluctuates frequently, a vortex flowmeter is a better choice because it can effectively avoid the problem of the vortex flowmeter being unable to "measure" or "measure inaccurately" at low flow rates.
Consider temperature and vibration: If the nitrogen pipeline has a high temperature (for example, above 80℃) or there is strong mechanical vibration at the site, the vortex flowmeter has stronger tolerance.
Consider the straight pipe requirement: Both flowmeters have certain requirements for the pipeline flow field. Usually, it is necessary to ensure that there is 3 to 5 times the pipe diameter (3 to 5 DN) in front of the instrument and 1 times the pipe diameter (1 DN) in the straight pipe section behind to ensure measurement accuracy.
Post time: Jun-24-2026