Tritium paint has been suited for the hands and lots of of watches since the 1930’s. At first this technology was Top Magic formula and restricted to use on military watches. https://www.californiasurvivor.com/
Tritium paint on watches is a mixture of tritium and phospor. Tritium is naturally radio-active and desires no external source of light or charge to work. Tritium does not light. Mainly because it decays, tritium gives off beta radiation, which are a group of thrilled electrons that in change excite the electron in the phosphor atoms making them emit photons, or light. Because they returning to their ground (non-excited) state, the phosphor glows. Phosphor can be excited by UV light from direct sunlight or other light resources. Thus, the tritium coloring relies on tritium radioactivity to help make the phosphor glow in the dark, no charge from external source of light.
Tritium, has a fifty percent life of 12. 3 years, a half-life is simply time it can take HALF of the tritium to decay. So as long as there is enough tritium in the paint, the watch will glow for years.
Scheduled to the toxicity of tritium based paint, a new technology was developed by mb-microtec in Swiss. This uses tritium gas sealed in vials. The principle is the same however the tritium gas triggers the coating on the vial to glow. The levels of radiation are so small that they pose no risk to the wearer. This technology has been used in the Traser H3, Luminox and Marathon military designer watches. In recent times SRB of Canada allow us a similar system, this is employed by manufacturers such as Smith and Wesson, Rescuer and NITE. SRB tritium is not as yet as well developed as the mb-microtec technology, only offering around 80 – 90% of the luminescence.
The main good thing about tritium in armed forces watches is that there is no additional drain on the watch power supply to power the night time light source, however these watches do have a drawback in that they could be picked up at great distance by night perspective equipment. Hence, it is important that these watches are protected during military functions at night.
As the technology has become cheaper it is finding its way in the civilian market. A large number of sportsmen such as fishers and shooters wear tritium based watches with Luminox and Traser being the most popular.
Annually more and more manufacturers are bringing new tritium pieces onto the market. Since the tritium light resources from SRB become more popular and along with less costly production in China, it won’t be long before we come across tritium used in purely civilian watches.