Summary of "Thermal Mass Flow Meter / Controller (Principle of operation)"
The video by Bronkhorst High Tech, a market leader in thermal mass flow meters and controllers, explains the operating principle of their EL-FLOW series thermal mass flow controller (MFC). Key technological concepts and product features include:
- Power and Status Indication: The EL-FLOW MFC operates on 15 to 24 Vdc, with LED indicators showing operational status (green LED means ready for use).
- Internal Electronics: Utilizes surface-mount device (SMD) technology for compact and reliable electronics.
- Measurement Principle: Combines a patented laminar flow element with a thermal mass flow sensor inside the instrument.
- Sensor Design: Features a thin capillary tube with a heater and two temperature sensors. When no flow occurs, both sensors heat evenly, indicating zero flow.
- Flow Control Mechanism: The instrument receives a setpoint (via PC, PLC, or analog input), which is compared to the measured flow. A PID controller adjusts an electromagnetic coil that moves a magnetic plunger against a spring to open or close the control valve.
- laminar flow element: Provides a predictable flow resistance, enabling calibration on nitrogen and modeling for other gases.
- Thermal Measurement: A portion of the gas cools one temperature sensor, while the other measures gas heated by the heater. The temperature difference correlates directly to the mass flow rate based on energy conservation.
- Control Feedback Loop: The microprocessor continuously adjusts coil current to maintain the plunger position and achieve stable, precise gas flow control within milliseconds.
- Application and Support: Bronkhorst emphasizes their expertise and willingness to collaborate to optimize customer processes.
Main Speaker/Source
- Bronkhorst High Tech (company presentation)
Category
Technology
