salut à tous, je fais mon petit parcour sur l'histoire de la SUB et je cherche les infos sur l'évolution de "SWISS" à "SWISS-T<25" etc. Si quelquin peut me donner un peu d'infos (dates ou modèle de passage de marquage) je serais gré.
Merci par avance

Bonjour
elements de réponse extraits de qualitytime.net. Autres informations disponibles dans le livre ROLEX report, assez facilement trouvable sur la baie.
JP


What does the "T" designation at the bottom of the dial mean?

This refers to the chemical used on the hands and hour markers, which causes them to illuminate. Around 1950, watchmakers started using Tritium as their luminous material, and began indicating the amount of that radioactive material with a designation at the bottom of the dial (i.e. T SWISS T or SWISS T < 25). Around 1998, watchmakers changed the designation to read SWISS or SWISS MADE, when they replaced the Tritium with LumiNova (an organic, non-radioactive chemical), as their source of luminescence.

T SWISS MADE T indicates that the radioactive material Tritium is present on the wristwatch. The amount of radioactive material emitted is limited to a maximum of 25 milliCurie.

SWISS T < 25 more specifically indicates that the wristwatch emits an amount of Tritium that is less than the 25 milliCurie limit.

SWISS T 25 indicates that the wristwatch emits the maximum allowable amount of Tritium (i.e. a full 25 milliCurie).

SWISS (or) SWISS MADE on wristwatches produced after (around) 1998, indicates the presence of LumiNova as the luminous material. (Please Note: "SWISS" or "SWISS MADE" was also the indication on wristwatches produced prior to the 1950s, when Radium was used as the luminous material. However, at that time "SWISS" or "SWISS MADE" simply indicated that the watch was, in fact, made in Switzerland.

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Les Chinois voient l'heure dans l'oeil des chats
Beaudelaire

Super, merci beaucoup
peut-tu me donner le nom exact du livre? merci par avance
je progresse dans ma recherche

auteur John E. Brozek, édité par INFOQUEST à Miami. Y'en a toujours qui trainent sur la baie, par exemple ici
JP

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Les Chinois voient l'heure dans l'oeil des chats
Beaudelaire