Fluorometric in situ measurements of water currents and mingling of waters in cases of heavy turbidity as in coastal shoal areas

By means of the in situ pulse-light fluorometer Variosens the fluorescent substance uranin was used to detect small water bodies. In mixture with a big river (Elbe) a quantity of 40-g uranin only was sufficient for tracer activities during 2 h and was a factor of about 50 above basic noise. It has been found that uranin in turbid water is highly superior to all kinds of rhodamine.