Secchi Disk – For Measuring Water Turbidity

A Secchi disk is an 8-inch (20cm) disk with alternating black and white quadrants. It is lowered into the water of a lake until it can no longer be seen by the observer. This depth of disappearance, called the Secchi depth, is a measure of the transparency of the water.

This simple-to-use Secchi disk (E46L) allows quick determination of turbidity or degree of underwater visibility in natural water supplies. It consists of a braided, stretch-resistant line and a weighted 20cm diameter black and white disc that sinks parallel to the waters surface.