Luminous dials have been a staple in the watch industry for decades, providing a convenient way to tell time in low-light conditions. But what exactly makes them glow, and how can you spot the differences between various types of luminous dials?
What Makes Them Glow?
Luminous dials typically contain a luminescent material that emits light after being exposed to a light source. The most common luminescent material used in watchmaking is Super-LumiNova, a non-radioactive substance that glows brightly in the dark. This material is charged by natural or artificial light and gradually fades over time, requiring recharging to maintain its luminosity.
Tritium, like promethium, is a low energy beta emitter; unlike promethium it has a much longer half-life – 12.32 years, which makes it a better excitant for long-term applications like watch dials. Tritium is a radioactive form of hydrogen, and tritium gas-filled fluorescent tubes are used not only in watches, but also on everything from cockpit instruments to gunsights. The best known users of tritium gas tubes for watch dials are Ball, Traser and Luminox.
How To Spot Their Differences
There are several types of luminous dials used in watches, each with its own unique characteristics. Some dials feature a single layer of luminescent material, while others may have multiple layers for enhanced brightness and longevity. Additionally, the color of the luminescent material can vary, with options ranging from classic green to more modern blue or even orange hues.
Another key factor to consider when comparing luminous dials is the application method of the luminescent material. Some dials have painted markers or numerals, while others may feature applied indices or even fully luminescent dials. These differences can affect the overall brightness and legibility of the watch in low-light conditions.
By understanding what makes luminous dials glow and how to spot their differences, you can make an informed decision when choosing a watch with this feature. Whether you prefer a classic look or a more modern aesthetic, there is a luminous dial option to suit your style and functional needs.
