Question about "Swiss made" T vs T25

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  1. #1
    G-Shock Moderator stockae92's Avatar
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    Question about "Swiss made" T vs T25

    I already aware of the "T" marking on Swiss Made watches. But when i was looking at this link:

    http://www.fhs.ch/en/faq.php#swiss

    it seems like the "T" is optional

    ISO 3157 Standard allows an optional marking for timepieces emitting less than a certain value.
    So, does it mean the watch marker doesn't have to put the "T" marking on the watch, but its optional. which in turn will means there may be watches with tritium (or promethium) without the marking?

    Also, I wonder if the watches with "T" marking does in fact emit less radiation energy than the ones with "T<25"

    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<25" means that the watch is Swiss and contains a certain quantity of tritium that emits less than 925 MBq (25 mCi).

  2. #2
    G-Shock Moderator stockae92's Avatar
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    Re: Question about "Swiss made" T vs T25

    on Ball watches that light up brighter than a Christmas tree (i.e. Night Train = 100Mc?), the marking on the dial is still "T Swiss Made T"

    so "T" emit less radiation energy "T25" can't be true and the marking on the dial would be optional

  3. #3
    Member lysanderxiii's Avatar
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    Re: Question about "Swiss made" T vs T25

    All timepieces with radionuclides (only tritium and promethium are allowed) shall be marked with the type of radionuclides used.

    According to ISO 3157, there are two type of worn watches with differing allowable activity: normal watches which are allowed 5.0 mCi,and special watches (e.g. divers) which are allowed up to, but not to exceed, 25.0 mCi. The 5.0 mCi is calucalted by dividing the total activity of the batch by the number of watches in the batch, but the total activity of any one watch in the batch cannot exceed 7.5 mCi.

    If the watch emits more than 7.5, but less than 25 it shall carry the "T<25" marking (activity of the watch). If it is is less than 5.0 it carries the "T" (average activity per unit in the batch, but no single unit shall exceed 7.5 mCi).

    Timepieces not intended to be worn or carried are allowed different levels of activity.

    EDIT:
    Ball watches should not be any more active than 25 mCi, it is the more effecient use of the radioactive energy and better phosorescent material that make them appear brighter. At least that is my understanding from Ball's literature.
    Last edited by lysanderxiii; January 18th, 2008 at 20:32.

  4. #4
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    Re: Question about "Swiss made" T vs T25

    Hi Stockae92,

    AFAIK, you're right.

    The "T" marking is optional, unless e.g. the specs in milwatches require it.

    Yes, the watches with "T" marking does in fact emit less radiation energy than the ones with "T<25".

    On the other hand, if the watch emits radiation energy more than 25 mCi, usually there should be warnings, e.g. H3 and/or "triange" nuke mark, yellow circle with red "triangle" nuke mark, red circle with red 3 H mark etc...on the dial, unless it's so called sterile milwatch. Additionally, on the back of the case there should be written the amount of mCi, e.g. 26 mCi and at least in case of US milwatches the NRC Id.

    Hope this helps...
    Cheers,

    MAJJ

  5. #5
    Member lysanderxiii's Avatar
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    Re: Question about "Swiss made" T vs T25

    Quote Originally Posted by MAJJ View Post
    Hi Stockae92,

    AFAIK, you're right.

    The "T" marking is optional, unless e.g. the specs in milwatches require it.
    Not according to ISO 3157. All civilian watches with radionuclides must carry either the "T" or "Pm." See above post.

    All Military watches with radionuclides carry different marking (e.g. the circle T, the red circle 3H, or H3) but are marked just the same.

  6. #6
    G-Shock Moderator stockae92's Avatar
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    Re: Question about "Swiss made" T vs T25

    Quote Originally Posted by lysanderxiii View Post
    EDIT:
    Ball watches should not be any more active than 25 mCi, it is the more effecient use of the radioactive energy and better phosorescent material that make them appear brighter. At least that is my understanding from Ball's literature.
    Ball does mention they have T<100 watches, so i guess they are doing more than T<25

    something like Night Train has so many tubes that it has to be over T<25

    even for the other Balls, like the Hydorcarbon divers, they have more tubes (number and length) than trasers, and they are both T<25

  7. #7
    Member lysanderxiii's Avatar
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    Re: Question about "Swiss made" T vs T25

    even for the other Balls, like the Hydorcarbon divers, they have more tubes (number and length) than trasers, and they are both T<25
    New Hydrocarbons and EMII's are marked "T25". Indicating they emit 25 mCi or less. In fact nothing in there new catalog seems to show the old "T<100" on the dial.

    From what I understand the EU no longer allows anything over 25 mCi.

    something like Night Train has so many tubes that it has to be over T<25

    even for the other Balls, like the Hydorcarbon divers, they have more tubes (number and length) than trasers, and they are both T<25
    They may have more tube and the tube may be bigger, but if the tube make more efficient use of a smaller amount of tritium, they will not be as active. Also, the design of the case, the case materials and the material used in the gas tubes themselves will have an affect on the total measured activity out side the watch.

  8. #8
    Member ballwatch's Avatar
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    Re: Question about "Swiss made" T vs T25

    Ball watches come in two flavors:

    T25: as previously discussed.
    T Swiss Made: 25<T<100

    T Swiss Made on our watches refers to watches between 25 and 100 mCi. This is for USA & Canada import requirements only. They require a distinction between the t25 and T100 levels for nuclear regulation purposes.

    Europe is another story altogether. Nuclear regulation is quite strict there, so we are not currently able to import into several important countries such as France or Italy. But we are hopeful that we will be there soon.

    In future, perhaps the dial markings will change, but for now that is how it stands.

    Regards,
    Jeremy Hogan
    Ball Watch Company

    ...needs to update his signature line.
    July 08 Newsletter: New World Record for Guillaume Néry, Diver GMT, Aviator
    Baselworld 2008 Newsletter: Guillaume Néry, Trieste Chronograph, Moonlight Special
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