Laminar Flow Differential Pressure Mass Flow Meter: Technical Principles and Advantage Analysis

2026-02-11

Word Size

Laminar Flow Differential Pressure Mass Flow Meter It is a precision flow measurement instrument designed based on Hagen-Poiseuille’s law. Its technical principle relies primarily on the flow characteristics of fluids in laminar flow—where the fluid moves in layers within the pipe, with each fluid particle following a smooth, straight trajectory parallel to the pipe axis. Under these conditions, the volumetric flow rate of the fluid exhibits a linear relationship with the pressure difference between the two ends of the pipe.

I. Technical Principle:

The laminar-flow differential-pressure mass flowmeter measures the pressure difference across a laminar-flow element and, using Hagen-Poiseuille’s law, calculates the volumetric flow rate of the fluid. Subsequently, this volumetric flow rate is corrected for pressure and temperature to obtain the standard volumetric flow rate and the mass flow rate. The key to this measurement method lies in ensuring that the fluid flows in a laminar regime, thereby maintaining a linear relationship between the volumetric flow rate and the pressure difference and guaranteeing high measurement accuracy.

II. Advantage Analysis

1. High precision: Due to the regularity of fluid parameters under laminar flow conditions, laminar-flow differential-pressure mass flow meters can achieve highly accurate flow measurements. Their measurement accuracy typically surpasses that of conventional differential-pressure flow meters, and they particularly excel in measuring small flows and low-pressure fluids.

2. Rapid Response: The response time of a laminar-flow differential-pressure mass flowmeter is extremely fast, largely due to the rapid acquisition of the pressure difference signal across the laminar-flow element. The propagation speed of pressure waves—also known as the speed of sound—determines the speed at which the pressure difference signal can be obtained, thereby ensuring the flowmeter’s quick response capability.

3. High repeatability: The laminar flow state of a fluid possesses inherent stability, which ensures that the measurement results of a differential-pressure-type mass flowmeter based on laminar flow exhibit high repeatability. In typical environments, gases usually move in a turbulent state; however, the laminar-flow differential-pressure flowmeter uses a laminar-flow element to maintain the gas in a laminar flow state, thereby enhancing both the stability and repeatability of its measurements.

4. Multi-gas adaptability: The laminar flow differential-pressure mass flowmeter can measure a variety of gases without the need for conversion factors. This is made possible by the linear relationship among volumetric flow rate, pressure difference, and gas viscosity as described by Hagen-Poiseuille’s law. As long as the gas’s viscosity coefficient is known, its volumetric flow rate and mass flow rate can be accurately calculated.

In summary, the laminar flow differential pressure mass flow meter—owing to its advantages such as high accuracy, rapid response, high repeatability, and versatility in handling multiple gases—has found widespread application in manufacturing sectors including semiconductors, biopharmaceuticals, new materials, and new energy.

Previous page

None

High-temperature mass flow controller flow meter

Next page

Previous page:

None

Next page:

High-temperature mass flow controller flow meter

Related Products

ACU10FA

ACU10FA

The ACU10FA analog-type mass flow controller features fast response and high precision. It offers a wide control range, with a flow rate capability spanning from 5 SCCM to 30 SLM, and can accurately measure and regulate flows as low as 1 SCCM—making it ideal for controlling even the tiniest gas flows.

Read more

ACU10FD

ACU10FD

The ACU10FD digital mass flow controller consists of a mass flow sensor, laminar flow separator, flow controller regulating valve, and amplification control circuit. It features digital signal input and output, offering advantages such as short preheating time, minimal zero drift, and high reliability.

Read more

ACU10FDR

ACU10FDR

The ACU10FDR low-pressure-drop gas mass flow controller is equipped with a proprietary high-flow electromagnetic valve, making it ideal for controlling mass flow even when system pressure is nearly unavailable. Its minimal pressure differential ensures the least possible impact on the system, enabling precise flow control under near-atmospheric conditions while significantly reducing system response time. We can customize the valve and PID control features based on your specific application parameters, guaranteeing fast, stable performance with minimized pressure loss.

Read more

ACU10FC

ACU10FC

The ACU10FC differential-pressure mass flow controller employs a differential-pressure-based mass measurement principle that features no thermal drift and zero response lag. It can simultaneously display and output parameters such as instantaneous flow rate, totalized flow, pressure, and temperature. When control functionality is required, an electromagnetic proportional control valve can be added, along with built-in PID regulation capabilities. Unlike thermal mass flow meters, the ACU10FC eliminates any additional "specific heat capacity" error when using gas conversion factors. As a result, even if the gas being measured differs from the calibration gas used at the factory, the measurement accuracy remains unaffected.

Read more

ACU10P Series

ACU10P Series

The ACU10P series pressure controllers/pressure gauges feature a straight-through design and cover a measurement range from 100 kPa to 10 MPa (both absolute and gauge pressures are supported). In addition, differential pressure transmitters are also available.

Read more