Fluorometers measure the fluorescence of algae, dyes or pollutants in the water. This measurement can be used for dye tracing studies, turbidity dredge monitoring, pollutant tracing , or estimating concentrations of phytoplankton and cyanobacteria (blue-green algae) for bloom predictions. These sensors are designed to work with a sonde or connect directly to a data logger. The parameters measured include chlorophyll, blue-green algae, dissolved organic matter, Rhodamine WT, Fluorescein, Phycocyanin, Phycoerythrin, Optical Brighteners, Crude Oil, Refined Fuels, PTSA Dye, Tryptophan, and turbidity.