Vraagje: T Swiss made T

Op “het andere forum” staat een draadje over een Red Sub 1680.
Op de foto daarvan zie ik onder op de wijzerplaat staan: "Swiss-T denk ik ook wel te begrijpen, maar wat zijn nu die T-en??
Wat betekent dat?

Hier een kopie van de site van de Fédération Horlogère waar het duidelijk uitgelegd wordt:


“T Swiss Made T” or “Swiss T 25” : what does it mean ?

In order for timepieces to be read in the dark, a luminescent material is laid on the dial indexes and hands. Generally speaking, the emission of light is either of photoluminescent type (determined by a exciting luminous radiation) or of radioluminescent type (determined by the radioactivity of the material).

Timepieces featuring radioluminescent emission are mostly designed for very specific uses : military watches, professional divers watches, etc. In this case, the use of radioactive material is strictly defined by ISO 3157 Standard which allows only two types of radionucleides : tritium (3H) and promethium (147 Pm). It is important to specify that these radionucleides emit a radiation of low energy.

ISO 3157 Standard allows an optional marking for timepieces emitting less than a certain value. The marking may be made on the dial as follows :

deposits activated by tritium : T

deposits activated by promethium : Pm

On the other hand, timepieces with a higher value, such as divers’ watches, must be marked as follows :

deposits activated by tritium : T 25

deposits activated by promethium : Pm 0,5

The indication “T Swiss made T” means that the watch is Swiss and contains a certain quantity of tritium that emits less than 227 MBq (7,5 mCi).The indication "Swiss T to indicate it.

Geweldig Maurits!

(wat kan je hier toch veel leren…).

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En zoek he? http://www.horlogeforum.nl/read.php?2,26466,26466#msg-26466