Water<unk>  Typical applications of water flow<unk>  include: *Plumbing/piping<unk>  *Leak detection *Checking for illegal tapping *Pollution studies *Natural waterflow analysis (rivers, lakes, ocean currents, cave waterflows, karst studies, groundwater filtration, etc.) *Sewer and stormwater drainage analysis Medicine and biology<unk>  may be used for the analysis of blood circulation within various parts of the human or animal body. For example, fluorescent angiography, a technique of analysis of circulation in retina is used for diagnosing various eye diseases. With modern fluorometers, capable of<unk>  single fluorescent molecules, it is possible to track migrations of single cells tagged by a fluorescent molecule (see fluorescein in biological research). For example, the fluorescent-activated cell sorting in flow cytometry makes it possible to sort out the cells with attached fluorescent molecules from a flow.
Dye tracing
Double dye test
Biotelemetry
Intravascular fluorescence
Foerster clamp
Doppler 
Entropy monitoring
Thorpe tube flowmeter