In the early 1970's, the Swiss firm mb-microtec in Biederwangen, Switzerland developed the technology to produce light sources so small, they can be installed on the hands and dial of a wristwatch.
These light sources, also known as trasers or GTLS (Gaseous Tritium Light Sources), are independent of a battery or any other source of outside energy, never need recharging or servicing, and do not require the push of a button to activate. They are 100 times brighter than anything comparable, and have an effective life span of more than 20 years. Self-luminous light sources for EXIT signs in places like public corridors or on airplanes to lead people to safety in an emergency during a power failure were some of the early and more traditional applications of this technology. Another common application for tritium inserts was night sights on firearms like this Glock 34.
Decades of research in the field of radioluminescence preceded the development and commercial use of trasers in wristwatches. mb-microtec trasers are tiny glass vials, hermetically sealed, coated on the inside with phosphorescent material, and filled with minute amounts of tritium gas. Electrons emitted from the gas excite the material to emit a permanent, cold light. Depending on the type of phosphorescent material used, trasers can be made to emit light in different colors. Green is the preferred color because the human eye perceives green to be the brightest in dark conditions.
Orange is also available and only slightly less bright. Blue is also an option but primarily used in watches for divers because under water blue remains visible at up to 60 meters in depth--longer or deeper than any other color. The P6500 Type 6 uses green trasers for all but the 12 o'clock position on the dial, which is indicated with orange. The serial production of trasers requires precision technology. Individual trasers are laser cut and sealed airtight so that no tritium gas ever escapes. After continuously improving the production process, mb-microtec today manufactures trasers which measure only 0.5 mm in diameter and as little as 1.2 mm in length. Unmatched in either size (small) or quality (luminosity), mb-microtec's traser light sources are state of the art and without equal in the marketplace.
Tritium (Hydrogen-3) is a radioactive isotope of hydrogen, and composed of one proton and two neutrons. Tritium is not stable but decays to helium-3 with a half-life of 12.3 years. In other words, half the tritium will have become helium-3 in 12.3 years. This transformation process is called beta-decay. In this process no gamma radiation occurs and only a low energy electron is emitted. The tritium is encapsulated in tiny borosilicate glass capsules coated with a phosphorescent paint. These capsules are installed into the bezel, dial, and hour and minute hands of the P6500 Type 6. Beta rays from the tritium gas hit phosphors in the vials, where the radioactive energy is converted to visible light.
Hence the glow you see, even when the watch has been stored in total darkness for very long periods. Traser watches need no external light source to "charge" the paint on the dial or hands in order to glow as do conventional luminous watches. Nor do they require a push of a button to light the dial as do watches with electro luminescence. Tritium has a half-life of 12.3 years, thus in 12.3 years the tritium vials will be half as bright as they were when the watch was new. A wristwatch fitted with tritium vials has a useful glow life of approximately 20 years. A Traser watch stored in complete darkness for several years and with a completely dead battery would look like the watch pictured above.
The Traser P6500 Type 6 Watch features:
- Tritium illumination on the unidirectional GMT bezel, dial, and hour and minute hands
- Continuous tritium illumination for more than 20 years
- Illumination 100 times brighter than other "self-luminous" watches
- No need to push a button or expose to light to activate illumination system
- Date function
- Black polyester 43 mm case and polyamide unidirectional bezel
- Mineral crystal
- Ronda 715 Swiss quartz watch movement
- Water resistance to 30 meters
- Shock resistance
- Black nylon NATO Strap
The stainless steel caseback is laser engraved with the model designation, production date, and other details. The caseback is secured to the case with four screws.
The P6500 Type 6 features a black nylon strap commonly known as a NATO Strap.
The NATO Strap features multiple stainless steel keepers.
The three keepers above the case retain the unused length of the strap when the wristwatch is worn. The NATO Strap is longer than standard so that the watch may be worn over clothing. The extra keepers retain the unused length of strap and prevent it from flopping about during use.
The keeper below the watch is to permit easy removal of the strap.
To remove the strap, simply pull the strap from the keeper.
This will expose the springbars.
Pull the strap from the case.
Removal is very simple. It is just as easy to reinstall the strap. Easy removal facilitates cleaning of both the strap and case.
In addition to being easy to remove, the NATO Strap is also very comfortable to wear, as the buckle is situated on the side of the wrist rather than on the bottom. If you type a lot, you know how much difference this makes.
The Traser P6500 Type 6 is not identical in every respect to the actual watches issued to the United States Military. The US Military were actually issued the Stocker & Yale P 650 Type 6, shown above.
The P6500 Type 6 is identical to the Stocker & Yale P 650 in all but a handful of respects. The P 650 lacks the date function found on the P6500 Type 6. The unidirectional rotating bezel on the P 650 lacks the hash marks below each hour number on the P6500 Type 6's bezel. Otherwise, the two watches are identical. Traser discontinued the P6500 a few years ago and replaced it the P6600, but decided to bring back the P6500 after uproar and high demand from P6500 fans. The P6500 watches we sell are not old stock; they are fresh production from the Traser factory with fresh batteries and tritium elements.
The P6500 Type 6 is a very nice field watch. But for the ultimate watch experience, there is the OMEGA Speedmaster Professional. After exhaustive testing, NASA issued the Speedmaster Professional to its Gemini and Apollo flight crews because of the Speedmaster Professional's reliability in all atmospheric conditions and for its manual-winding c.1861 movement which functions in the weightlessness of space. The Speedmaster Professional features a chronograph that can measure accurately down to 1/5th of a second. A tachometric bezel surrounds the shock-resistant hesalite crystal and permits the accurate measurement of speed. The Speedmaster Professional also features a steel caseback engraved with the famous words that proclaim this wrist chronograph's unique pedigree: "FLIGHT-QUALIFIED BY NASA FOR ALL MANNED SPACE MISSIONS; THE FIRST WATCH WORN ON THE MOON".