Tritium lighting watch

Tritium illumination

— illumination method used in clocks with arrows. The light sources in such systems are miniature flasks mounted on the hands and dial markers filled with tritium, a radioactive isotope of hydrogen. From the inside, the flasks are covered with a phosphor, which glows under the influence of decaying tritium.

We emphasize that such systems are absolutely safe: the radiation does not even go beyond the flasks, not to mention the watch case, and the amount of tritium in the flasks is negligible, and it does not pose a threat even if the flasks are damaged and leak (which in itself is very unlikely) . At the same time, such illumination has a number of practical advantages. So, it does not require power and is suitable for watches with any type of mechanism; and the brightness of tritium is noticeably higher than that of a conventional luminescent coating, moreover, it does not depend on the length of stay in the dark. However over time, this brightness still decreases due to the gradual decay of the "fuel" — however, this happens very slowly: in order for the backlight to dim by half, it takes about 12 years, and for a complete loss of efficiency — at least 20. But the unequivocal disadvantage of tritium systems is high cost.