Application

• Concrete intake channel
• 3.0 x 2.0 m (w x h)
• Partially filled
• Gravel bed

Definition of tasks

• Flow measurement to ensure a minimum water volume required for the fish ladder
• No sensors can be installed on the channel bottom
• Contactless measurement if possible on inaccessible point (risk of vandalism)
• Medium accuracy requirements

Solution

• A contactless surface radar system Type OFR was installed in the fish ladder approach under a bridge.
• The system measures the speed of surface waves resulting from the rough channel bottom (gravel bed). The current flow rate is calulated from this velocity and the current flow level which is measured contactlessly as well.
• The flow rate is passed on as mA signal to a PLC on site which controls the position of a slide valve upstream of the measurement point