Mercury Dosing in Fluorescent Lamps

Low pressure mercury lamps are very efficient light sources, but for the radiation generation they exploit mercury that has a strong negative effect on the environment. Worldwide regulations are pushing for the reduction of mercury content in fluorescent lamps in order to minimize their environmental impact. The trend of Hg content reduction is requiring advanced technological solutions for safe and precise Hg dosing in lamp down to low level. The old liquid mercury dispensing technology, involving risks of contamination with new more reliable and more environmental friendly mercury dosing solutions. The innovative technologies exploiting Hg dispensers based on stable mercury compounds are very reliable solutions for a safe and controlled delivery of small amounts of mercury. The paper will present main methods used to introduce mercury in flourescent lamps, especially focusing on the characteristics of the new Hg dispensers based on inter-metallic compounds that allow to accurately dose mercury even at very low level.