The D-FL 220T continuously measures flow velocity and flow direction in tunnels. Its ultrasonic sensors provide reliable measurement across the tunnel profile for tunnel ventilation control systems.
Two identical sensors alternately transmit and receive ultrasonic pulses. The system evaluates the transition times dependent on direction and calculates flow speed.
Key Benefits
- Extremely low maintenance
- Reliable measurement across the tunnel profile
- Stand-alone system, no control unit required
- Simple configuration
- Corrosion resistant against aggressive tunnel atmosphere
- Withstands lavation process in tunnels
- Sensors can be replaced quickly, no tools, no re-alignment required
- Signal transmission
– per 4-20mA analog signal and 2 relays
– per RS 485 bus via MODBUS RTU protocol - Minimal spare requirements.
Applications
Slow measurement:
- Road tunnels
- Railway tunnels
Signals for ventilation control system
- Monitors air flow speed
- Enables control of flow speed in case of fire
