The Scanner Unitscanner

The Scanner is installed in fish ladders, pools, traps or similar places where all the fish in the river have to pass. It consists of two scanner plates (20 x 60 cm) inside a frame, the distance between them being from 10 to 45 cm. Inside the scanner, light diodes send infra-red light beams to receivers on the other side.

When a fish swims through the net of light beams, the resulting silhouette image is used to count and estimate the size of each fish. Each individual image is memorised in the control unit so that the counting can be verified afterwards.

 

The Control Unitcontrol_box

The Control Unit receives the information from the scanner and stores it. It can be connected to a computer for processing the data as often as required.

The temperature of the water is measured at programmable intervals and the date and time of day that each fish passes the counter is also recorded. In this way their movements can be correlated with environmental factors.

The power supply consists of solar panels and a deep cycle battery.