Mass Flow Controller (MFC)

Why choose mass flow control (MFC) instead of volumetric flow control?

Volumetric Flow Controller: Measures the volume of gas per unit time. Its readings are easily affected by ambient pressure and temperature changes. For example, a temperature increase causes gas to expand, so at the same volumetric setting the actual mass of gas passing through decreases; conversely, increased pressure means more gas molecules are contained in the same volume.
Mass Flow Controller (MFC): Directly detects and controls the actual mass of gas. Because mass is not affected by pressure and temperature changes, an MFC can provide a constant, repeatable gas flow under varying environmental conditions, making it the ideal choice for precision applications.

In short: volumetric control focuses on “how much space is occupied,” while mass control focuses on “how much substance is present.” For applications requiring precise chemical reactions or process stability, mass is the critical parameter.

Ultra-high accuracy and fast response

Piezoelectric ceramic elements produce minute deformations under applied voltage, enabling continuous, highly sensitive valve adjustment.
Closed-loop control systems monitor flow deviations in real time and quickly adjust valve opening to ensure the setpoint is achieved precisely.
Supports high-speed measurement principles such as differential-pressure-based methods, delivering excellent dynamic performance.

Exceptional energy efficiency and low heat emission

Zero hold current: piezo valves consume energy only during actuation and require almost no power to maintain position.
Significantly reduces overall power consumption, especially suitable for energy-sensitive applications.
Avoids coil heating, preventing interference with temperature-sensitive process environments (e.g., semiconductor cleanrooms).

Silent operation and high reliability

Fully silent operation, suitable for medical or laboratory environments with strict noise requirements.
Compact structure with very few moving parts, virtually no wear, very long service life, and minimal maintenance needs.

Compact design and flexible integration

Small size facilitates integration into space-constrained equipment.
Supports digital interfaces, easily integrating into Industry 4.0 and smart automation systems for remote monitoring, diagnostics, and data acquisition.

Operating principle and measurement technologies Festo MFCs operate in a closed-loop control circuit: sensors measure the gas mass flow in real time, the controller compares the measured value with the setpoint, and drives the piezo valve for precise adjustment to eliminate any deviation. Common mass flow measurement principles include:

Thermal principle (thermal mass flow): Estimates mass flow from the heat loss or transfer when gas flows past a heat source; widely used.
Differential-pressure principle: Calculates flow by measuring the pressure drop across a throttling element; offers faster response and superior dynamic performance.

Coriolis principle: Measures mass flow directly with extremely high accuracy; suitable for specific high-demand applications. Festo selects the most suitable measurement technology according to the application requirements and combines it with piezoelectric actuators to provide optimal solutions.