In the world of watches, phosphors play a vital role in improving visibility, especially in low light conditions. So what is what is lume on watch? simply put watch lume refers to the phosphorescent luminescent substance that coats the dial and hand of a watch. This lume watch has developed from the original radioactive radium to a less toxic compound. So in this comprehensive guide, we’re going to delve into what lume is on a watch, how long watch lume last, how watch lume works, tritium vs luminova, and everything else about luminous watch.

What is lume on a watch?

Nowadays, a luminous watch is a watch that glows in the dark, even in a dark environment such as when you’re scuba diving or in the middle of the night, it can easily allow you to see the time. The most common type of watch lume comprises pigments based on photo luminescent materials. This is a non-radioactive substance, similar to radium, which applies to watch hands, watch bezel and dials and glows in the dark by absorbing and re-emitting light. Photo luminescence is the activation of luminescent materials when exposed to natural or artificial light, which emits light.

The radium mentioned here was the material used for luminous watches in the early 1900s, but because radium is radioactive, this radioactivity can remain for decades and can be harmful. Watches manufacturers therefore realized that accessories such as radium-coated dial hands were not sustainable.
So they started looking for an alternative material and found tritium. Tritium, a radioactive isotope of hydrogen, is a safer alternative to the banned radium, which was commonly used in luminol until 1998.
And today’s watch fluorescents are the photoluminescence just mentioned, but this material only lasts for about 7 hours. The search for new luminescent materials continues, resulting in the discovery of Luminova, Super Luminova, and tritium tubes.

Luminova and Super-LumiNova

In 1941, a Japanese man named Kenzo Nemoto started a luminous paint business. During World War II, he supplied the Japanese military with glow-in-the-dark paint business. After the war, the Japanese military’s need for this service decreased, so he painted watch hands and upper scales on watch faces, and further developed phosphorescent pigment technology. Luminova, the technology, was officially named, patented, and licensed to other watch brands and manufacturers in 1993.
The Swiss company RC Tritec AG was established and registered as Super-LumiNova in the same year, granted a license to manufacture and distribute LumiNova. The Super-Luminova is therefore a Japanese invention but Swiss made.

Tritium tube watch

Tritium tubes are now used differently than tritium as a fluorescent agent as mentioned above. In the past, tritium was applied directly to watch dial with no protection. In contrast, tritium is now made into a gas and sealed in a tube, making it virtually risk-free.

Tritium is sealed in a tube as a gas, this is called a tritium tube, tritium gas tubes are usually mounted on faces or watch hand. The luminous principle of tritium tube is that the inner wall of the tube is coated with phosphorescent material in the mineral glass washed into the gaseous tritium, tritium and phosphorescent material react to produce a cold light source, this light source does not have dazzling light and heat dissipation, so there is no need to rely on any source of light, to achieve the self-luminescence of zero energy consumption. Tritium watch can withstand deep-sea operations, high vibrations, and harsh extreme environments, and can emit light for up to 25 years. That’s why some dive watch now has tritium tubes on the watch hand and hour marker on watch dial.

How long does watch lume last

As mentioned earlier, in the absence of light, luminova watches typically glow for about 7 hours. However, the luminescent coating of super-lumiNova lasts for the entire life of the watch. This is because it works like a battery, storing energy and emitting light continuously and repeatedly. Tritium watch can glow for up to 25 years. Hence, the customer can customize and design the watch according to their needs by choosing the right luminous material.

How does watch lume work?

The photo luminescent material stores luminous watch work on the principle. In the watch industry, this material is referred to as phosphorescent material. In a dark environment, a watch accessory coated with phosphorescence, such as a watch hand or hour marker on dial, slowly releases the light.

Tritium vs luminova

Tritium and luminova are two common luminescent materials used in watches. Both materials use phosphors in the luminescence process, and the principle of luminescence is that the luminova material undergoes some chemical reaction. Luminova is typically printed or coated on the dial, whereas it is in powder form. However the luminova watch hand or hour marker need other light source to charge. Tritium is a gas encapsulated in a tube, typically mounted on a dial, and does not require an external energy source.

About Super-LumiNova

The super-LumiNova discussed RC Tritec AG, a Swiss company produces earlier. We will provide a comprehensive introduction to Super-Luminova, aiding customers in making informed decisions.

Super-Luminova is available in a variety of colors with the following color codes:

C1 – White, approximately 31% as bright as C3

C3 – yellow, the brightest

C5 – yellowish-green with 89% brightness

C7 – green with a brightness of 84

C9 – blue-green with a brightness of approximately 83

BGW9 – light blue-white, about 95% as bright as C3

Old Radium – appears as an aged/vintage tritium fluorescence during the day, but glows a bright yellow-green color at night.

Old White – off-white during the day, yellow-green at night

Super-LumiNova grades:
Standard
Grade A
Grade X1
Grade X1 is the latest formulation of SLN. According to RC Tritec, X1 grade provides a 60% increase in brightness after two hours. This increase is based on a comparison between standard and X1 grades.
Note: Not all colors/pigments are available in all grades. For example, C3 (green) is available up to X1 grade, but BGW9 (white) is only available in standard or A grade.

Conclusion-Watch lume

Watch lume is an essential feature that improves the readability of a watch in low light conditions. For watch enthusiasts and potential buyers, it is important to understand the longevity, principle, and function of luminescence. As a professional watch factory, we can customize luminous watch according to customers’ needs and help customers create own watch brand.

At present, our luminous materials include Hong Kong Luminous (colors from HN1, HG2, HL3, HK7, SG-2, SO-02, etc.), Japanese Luminous (J-24B), Swiss Luminous (DS-1, DS-2, DS-3, C3, BGW9, etc.)