Fieldmaster Secchi Disk (LSE) Need to determine how clear the water is? Seeing may not be believing. Measure the turbidity or degree of visibility of the water you’re testing with our limnological secchi disk. Just like the professionals, you’ll leave nothing to chance, because this is real equipment for the real world. Results are meaningless if they’re not repeatable and can’t be compared. Our sturdy plastic secchi disk handily meets industry standards. It is 200 mm in diameter (7-7/8”) and has four quadrants, two white and two black. We include 20 meters of 1/8” diameter line on a styrofoam form that will float if dropped in the water. Plus instructions that are written at a basic level.   Most scientists use a Secchi Disk to determine the index of suspended matter in the water. The smaller the index - say, five feet - the more suspended material there is. The water is, obviously, less transparent, with a lower degree of visibility. You can also use a Secchi Disk to measure the depth of light penetration and can derive a rough estimate of the extent of the littoral zone. Or you can use it more prosaically - as a sounding line and weight. You can measure the depth of the water at any given point during your research. Qty :