Forel-Ule scale

In the Forel - Ule scale is a measuring method, the color observed a body of water can be determined; it is used in applied limnology. With the help of different inorganic salts a color palette is generated in the water tubes and compared with the color of the water. The result is a color index for the water.

It was originally developed by François- Alphonse Forel. Three years later, the German Limnologist Willi Ule refined this method. This scale is used now little more, because it is very approximate and depends on the observer and his subjective perception of color. It was later replaced by the so-called platinum - cobalt scale that is less subjective.