... Breitling watches , can you tell when Breitling stopped using Radium and started using Tritium ? , my guess is somewhere in the mid 50ies but it may help to date watches if we can narrow it down to a year or 2 years. As Radium was radio active and Tritium a safe replacement I can only assume there was a 'cut in' date where all watches from that point on contained Tritium instead of Radium on the dial and hands
edit : Radium , not Barium !
there is only one possibility: To believe what is written on the dials! Most probably Breitling was one of the first to use Tritium for their dials and hands and to mark this on the dials with a ' T ' added to ' Swiss Made '.
As another result (vide viewtopic.php?f=11&t=19598&start=15
) shows, I have good experience in directly contacting the manufacturers of products as the best way to get clear answers.
The Swiss Manufacturer of RADIUM, TRITIUM and LUMINOVA is
(RADIUM CHEMIE A.ZELLER & CO.)
RC TRITEC AG
and I contacted already beginning of 2008 its CEO and owner Mr. Albert Zeller to possibly get some information about the use of RADIUM, TRITIUM and LUMINOVA in the watch business. Reason: My 1955 Navitimer with the all black dial had ' Swiss Made ' without the ' T ', but the 1962 Navitimer dial had the 'Swiss Made T '.
Here is the result of the phone conversations + email exchange with this extremely nice and obliging elder gentleman:
a) Although TRITIUM was already available in the early 60s, certainly not every manufacturer of dials or
hands immediately started to use TRITIUM instead of RADIUM.
b) A missing ' T ' on the dial does not necessarily mean, there was not TRITIUM used resp. there was still
RADIUM used, because marking the dial with a ' T ' was purely volontary.
c) Since 1975 there exists the ISO 3157 ( International Standard - Radioluminiscence for time measuring
instruments - Specifications). Thus only since then manufacturers of watches are liable to mark the dials.
Don't waste your money for a Geiger counter but much better "waste" it for a bottle of single malt that you can drink on a cosy evening while deliberating how you can use your Troll Spray on MrGoodfornothingMichaelWhatshisface.