A brief comment by DOXA about the luminosity of tritium equipped watch dials (applied, coated or using vials), has started a heated debate on several forums, we like to thank all contributors and kindly ask everybody to stay civil no matter how this discussion evolves.
The statement made by DOXA is about the limit of the application of a maximum of 25mCi radioactive compound on wrist watch dials, this limit was taken in consideration while designing the DOXA SUB800Ti and this has 3 reasons;
1. Tritium compounds are radioactive, and it is believed that 25mCi is the maximum radiation found in nature under normal circumstances, obviously laboratories, power plants etc.. (Not really considered Nature) have their own standards, limits and do not comply with the above. For this reason, Swiss watches manufacturers were forced by the FHS and by public more than 20 years ago to limit the application and the emission of luminous substances used on watch dials to a maximum of 25mCi.
2. Radium, Tritium and other radioactive luminous substances used on wrist watch dials that exceed the 25mCi are banned from import in many countries around the world. In some countries, the usage of radioactive substances is entirely banned in the wrist watch industry.
3. Finally and most important is the compliance to military specifications, which dictates the above limit by applying the following measuring procedures:
So whether there is an exception to the above limits, and whether other brands comply and whether their customers care about the above limits, it is their choice, and DOXA will by no mean debate, argue or get involved in any discussions about applications that exceed the 25mCi limit. What really is important to DOXA, is to comply with the above guidelines, and to offer a solid tool watch that is safe to use, and finally be able to submit to NATO defense departements a reliable wrist watch that complies with the US and NATO MIL-SPECS. It has also been taken in consideration that the 800Ti must incorporate arabic numeral indexes in order to comply with the above SPECS, which was taken care of on the submitted samples.
3.6.1 Contamination. Completed watches shall be tested for contamination after having been
subjected to all the environments of table I. They shall be wiped with a Metricel GN-6 or
equivalent wipe, moistened with deionized or distilled water. Within 1 minute of wiping, the wipe
shall be placed in a scintillation counter. Each resulting wipe shall indicate a removable
contamination level of not more than 100 disintegrations per minute (dpm).
3.6.2 Long term contamination (Qualification only). Completed watches shall be packaged in
accordance with 5.1 for a period of not less than 90 days. They shall then be wiped with a
Metricel GN-6 or equivalent wipe moistened with deionized or distilled water. Within 1 minute
of wiping, the wipe shall be placed in a scintillation counter and the disintegrations measured.
Each resulting wipe shall indicate a removable contamination level of not more than 100 dpm.
3.6.3 Diffusion. Completed watches shall be submerged in a measured volume of distilled or
deionized water, equal to approximately 10 times the volume of the watch, for 24 hours at
23 °C ± 1 °C (73 °F ± 3 °F). The watches shall then be removed from the water and the water
measured for radioactive content. The diffusion of contamination into the water shall not exceed
50 nanocuries per 24 hour period (see 3.5.5).
The above is an excerpt of the MIL-SPEC Document W46374G
copyright: Defense Standardization Program Office (DLSC-LM), Ft. Belvoir, VA 22060-2533, USA
We like to thank everyone for their contribution and emphasize, that DOXA reserves the right to remove offensive postings or postings containing incorrect information.