Determine and monitor the correct transmission
The UV-C light must be able to penetrate the liquid well in order to reach and break down the micro-organisms everywhere. The correct transmission of a fluid, or light permeability, is therefore of great importance. The less light the liquid absorbs, the better the polluting organisms can be reached. A high transmittance means the light penetrates deep into the liquid and the further this light penetrates, the more water can be illuminated at the same time with the same power. The transmission is usually measured over a distance of 10 mm (T10) or 50 mm (T50) and the result is displayed in percentages, so with 90% transmission T10 90% of the light is transmitted through 1cm of liquid.