So you just got a great new sports watch, thrilled that it has all the bells and whistles you were looking for—including luminous hands and hour markers, which are probably described in the company literature as “Super-Luminova” coated. And while you may know the effects of the stuff, do you really know what Super-Luminova is?
In the early 20th century, Guido Panerai created some of the earliest luminous watches for use by the Italian navy, using radium bromide and zinc sulphide. He garnered a patent in 1915 and the original Radiomir watch was born. Later, Tritium—a radio-luminescent substance containing tritium—was the substance of choice to coat numerals, markers and hands so they could be read in the dark. But the use of radium posed problems, and its use in wristwatches was banned in the U.S. in 1968 by the National Council on Radiation Protection & Measurements (NCRP). The rest of the watchmaking world soon followed suit. And health concerns began to be raised about tritium, prompting regulations surrounding its use.
Photo-luminescent material provided an answer, since it absorbs light and emits it over time, as opposed to self-luminescent–and potentially harmful—materials. Thus phosphorescent pigment, which can continue to glow for hours, was the material of choice. The downside? Photo-luminescent pigments—like Super-Luminova—must be “charged” with light in order to glow. Watchmakers such as Ball watch and Luminox still employ tritium—in gaseous form in tiny glass tubes—since it doesn’t require any ambient light source to achieve its glow and it poses no health threat when used this way. In addition, its glow is constant, as opposed to Super-Luminova whose glow will deplete over time and need to be charged once again.
Super-Luminova pigments are non-radioactive and non-toxic, and certain grades of new chemical compositions have much greater brightness than previous materials. The pigment operates like a light battery, meaning that after sufficient activation by sunlight or artificial light, it will glow in the dark for many hours—just what one needs when out late trick-or-treating on Halloween night.