Rhodamine is a red coloured dye frequently used as a tracer dye in water flow, transport and dilution studies. It is highly fluorescent and can therefore be detected in very low concentrations by appropriate instrumentation. It is useful for tracing pollutants, studying aeration, and dispersion as well as many other applications to understand the movement of water.
One of its most common uses is measuring time of travel for surface, ground and wastewater. Time of travel refers to the movement of water borne substances from one point to another in a stream/lake during steady or gradually varied flow conditions. The Rhodamine is injected into the water and the concentration of the dye is then measured downstream using a fluorometer.