SEM-S200 Tunnel Airflow Sensor is specifically designed for for the tunnel application, it’s working based on ultrasonic time-difference method, the two ultrasonic probes were installed on both sides of the tunnel wall and face to each other, when tunnel airflow passes between the two ultrasonic probes, the time difference between the round-trip times of the ultrasonic waves transmitted by each other is changed by airflow. By measuring the time difference, the airflow velocity is obtained.
A built-in time delay, variable from 00-99 seconds can be set to prevent very short duration gusts from causing false alarms. Only when wind speed reach preset value limit and last time exceed time delay, will the corresponding relay be triggered.If additional connections are made, the alarm can cause a remote warning light to flash, sound a remote horn or siren, and automatically actuate the crane brakes to prevent the crane from rolling.
Typical Application
Measuring the air velocity and flow direction
Ventilation control in road and railway tunnels or similar structures
Detection of smoke propagation during tunnel fires for efficient fire fighting
