THE REAL TRUTH ON LUMINOUS WATCHES
If you are often caught staring at luminous watch, admiring its glow, you are not alone.
While most of the watches for men today utilize fluorescent luminous materials such as Superluminova, LumiBrite etc, do you know watches in the earlier hey-days use radioactive luminous materials such as radium and tritium for luminous purposes?
RADIOACTIVE LUMINOUS MATERIALS
Radium was first used with zinc sulfide in the early 1900’s to produce luminescent properties in watches. As its luminescence was weak, more amount of radium is required to emit decent luminescence in watch’s markers. While the radium was enclosed in the watch case and was too low to affect wearers, the heavy exposure of radium posed an extremely dangerous work hazard for watch lumers. This also explained why tritium was used which had much lower levels of radiation.
Despite many watch manufacturers claims, tritium generally does not provide the brightest luminescence in watches and due to its half life longevity, its luminescence will run out in 10-20 years. However, the biggest advantage of tritium is that it does not need any ambient light source to charge itself and will provide a constant luminescence throughout, providing unlimited visibility at all times. A point to note that, as the luminescence of tritium depletes, it creates a nice patina that enhances the beauty of older watches.
FLUORESCENT LUMINOUS MATERIALS
Used in many unique vintage watches today, fluorescent luminous material is a much safer alternative. After a brief exposure to sunlight or artificial light, it provides an stronger initial luminescence where many lume lovers enjoy. The glow intensity will begin to taper off, becoming less luminous for the next 6-8 hours. Another advantage of fluorescent luminous materials is that they have a sustained glow intensity, losing only 5% of its maximum brightness over 10 years.
Fluorescent luminous materials such as Superluminova are widely used in today’s top watch brands such as Panerai.