Another crucial aspect of UV disinfection is the liquid’s transmittance. The UV-C light has to be able to penetrate the liquid to reach the micro organisms, of course, even those far away from the lamp. The less light the liquid absorbs, the better the organisms are reached. With high transmittance, the light can deeply penetrate the liquid. The farther the light penetrates, the higher the emitted UV dosage to the medium.
Transmittance is usually measured over a distance of 10 mm (T10) or 50 mm (T50), and the value is usually shown in percentages.