Why the "T" disclosure for Tritium...

[Speed]

I am not near my Mondani Submariner Story Book...thought I would ask...

Why did Rolex label their dials / feel the need to point out their dials were made with Tritium? In retrospect, the T designation on dials makes it nice to ID vintage pieces, but what was the original intent? Was it because Tritium is a dangerous material or??

[winged wheel]

As a nuke worker, I think it's probably because tritium is a radiation source regulated by the NRC, and I would imagine other nations regulatory bodies, as well. If you look at the NRC web sight, half of the industry event are lost or stolen tritium exit signs (walmart being one of the worst offenders). JM $0.02.

Jim

[PhilM]

It's because it's radioactive, therefore it had to be labelled accordingly

[Speed]

Riiiiiiiiight. Thanks!

OK. It's coming back...and the luminosity is now going / gone on many of these prior pieces.

[winged wheel]

12.33 years. It's bound to fade eventually.

[padi56]

Originally Posted by masugu

I am not near my Mondani Submariner Story Book...thought I would ask...

Why did Rolex label their dials / feel the need to point out their dials were made with Tritium? In retrospect, the T designation on dials makes it nice to ID vintage pieces, but what was the original intent? Was it because Tritium is a dangerous material or??

At the time it was law to have any radioactive material clearly stated on dial or on any product. The T Swiss T dials contained the radioactive material Tritium but less than 277 MBq [7.5 mCi].The T > 25 dials less than 925 MBq [ 25 mCi].And there were many cases of dial painters getting quite ill using this radioactive materials .They were encouraged to keep a fine point on their paint brushes by licking the brush end.So it was phased out around 1998 for the much safer luminover

[ersnyder]

Originally Posted by winged wheel

12.33 years. It's bound to fade eventually.

My '89 Exp II is now completely dead. When I first got it about 12 years ago it had some short life to the glow.

[Speed]

Thanks Padi, WW.

Great explanation on the T > 25. I was going to ask Padi.

[RebreatherDiver]

Originally Posted by winged wheel

12.33 years. It's bound to fade eventually.

Yep, no escaping the T 1/2

[larrysb]

Originally Posted by padi56

At the time it was law to have any radioactive material clearly stated on dial or on any product. The T Swiss T dials contained the radioactive material Tritium but less than 277 MBq [7.5 mCi].The T > 25 dials less than 925 MBq [ 25 mCi].And there were many cases of dial painters getting quite ill using this radioactive materials .They were encouraged to keep a fine point on their paint brushes by licking the brush end.So it was phased out around 1998 for the much safer luminover

Uhh, this is absolutely NOT true.

The problem with watch and instrument dial painters was not with tritium, but with RADIUM. It was the "radium girls" case that you are thinking of. Google it, you'll find the details.

Radium produces lots of high-energy decay and is quite dangerous on exposure or worse, ingestion. Radium is radioactive for thousands of years, even though the glowing paint fades in a couple of decades. The radioactive particles banging into the paint degrade and destroy it into a brown, non-glowing mess.

Tritium has an excellent safety record and as far as I can tell, there are no proven cases of a single person injured by tritiated paint for watch illumination. Tritiated paint is no longer available, but tritium tubes and microspheres are readily available and still in use. Even when abused and ingested, the actual risk from tritium is exceedingly low. It is a low-energy beta emitter.

The real problem is that tritium has a half-life of 12.6 years. Every 12.6 years, the illumination will halve in brightness. After 25 years, the light output is essentially zero. Also the chemistry is unstable in the long term. The paints in particular will simply degrade and flake and change colors.

The tubes and spheres are very safe and don't chemically fail, but the isotope itself simply decays below useful levels in a couple of decades.

Because of the radiation-phobes, anything radioactive, no matter how slight, is a regulatory nightmare. There are markets too, which will not buy radioactive devices, even if regulatory approval is possible, period.

Luminova (strontium aluminate with europium dopant) has many advantages over the radioactive tritium. It is chemically stable, completely non-toxic and non-hazardous. It lasts forever (more or less). 50 years from now, it should work about as well as it does today. The downside is it must be charged in bright light and it fades fairly rapidly. However, it will last long enough to provide useful illumination to the majority of watch wearers over the night.

[Yoreese]

I miss the look of my tritium dialed Sub!

[Hawk99]

...And I mean little!!
If I wake up in the middle of the night and take a look to see what time it is, I can see a faint glow of the indicies, but bright enough to make it legible.
Very cool!

[mascot]

So you dont need to "load" it with daylight?

[GeoGio Greece]

Originally Posted by Hawk99

...And I mean little!!
If I wake up in the middle of the night and take a look to see what time it is, I can see a faint glow of the indicies, but bright enough to make it legible.
Very cool!

What have happened to the cyclops eye ? Is the acrylic changed with the Non Date or was is rubbed down ?

...and, do you "charge" it ? There were some posts mentioning that owners 'charge" their watches, but I cannot make mine to glow !

[Hawk99]

Originally Posted by mascot

So you dont need to "load" it with daylight?

No, and it doesn't/wouldn't make a difference. Tritium glows on its own due to its radioactivity nature. From what I understand, it is the radioactivity inherent in Tritium which excites the lume and creates a glow. Holding it up to a light does not do anything.

Originally Posted by GeoGio Greece

What have happened to the cyclops eye ? Is the acrylic changed with the Non Date or was is rubbed down ?

...and, do you "charge" it ? There were some posts mentioning that owners 'charge" their watches, but I cannot make mine to glow !

The original 'top hat' crystal (tropic 127) was changed to a dome style (tropic 19) more commonly seen on the 5513. They are interchangeble on the 1680 and 5513. I just didn't care for the cyclops and love the new clean look.
Tritium dials do not take a charge. You could say they are 'self charging', but it does wear out eventually. The newer dials with luminova DO take a charge and are very bright.

Regards,

[GeoGio Greece]

Originally Posted by Hawk99

No, and it doesn't/wouldn't make a difference. Tritium glows on its own due to its radioactivity nature. From what I understand, it is the radioactivity inherent in Tritium which excites the lume and creates a glow. Holding it up to a light does not do anything.




The original 'top hat' crystal (tropic 127) was changed to a dome style (tropic 19) more commonly seen on the 5513. They are interchangeble on the 1680 and 5513. I just didn't care for the cyclops and love the new clean look.
Tritium dials do not take a charge. You could say they are 'self charging', but it does wear out eventually. The newer dials with luminova DO take a charge and are very bright.

Regards,

Thank you