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Hi all, I have this lovely 806 I bought on SC a while ago and it has service replacement hands (not sure when this was done). I think these are tritium based on the fact that they give off a dim glow and don't seem to respond to a charge from bright light. However, they look so new that I'm doubting it. Would anyone be able to confirm if these are tritium or luminova please?
https://farm2.staticflickr.com/1821/...f0e31a9d_b.jpg
https://farm2.staticflickr.com/1788/...417624b4_b.jpg
Look like luminova to me...
2 tests:
1. If left face down overnight do they still glow with the same intensity? If so likely to be trit.
2. Do they glow under UV light? If so they are likely Luminova.
2 is not true. UV can excite the lume in trit.
Trit lume is a luminescent material and the trit to excite that material (and a binder to hold it together). The lume can be excited by light, but the glow fades quite quickly.
Dave
Go by test 1 above. Put the watch in a box and open it up hours later in the pitch black. If the hands are glowing (of their own accord) then they're almost certainly tritium. If they need to be excited by an external light source and fade away in the dark, then they're probably not.
OK, thanks guys. I'll give it the dark test.
I am not sure these tips are very useful. I find this works for me. Hold it up to a light bulb in a dark room, then turn off the light.
Old Tritium hands usually glow for a shortish period when charged under bright artificial light or UV and die within about 30 seconds, unless its Rolex or Tudor then its dead as a door nail.
If its Luminova and charged in the same way it will glow brightly and should continue to do so for some considerable time
The colour looks very similar to the luminova used on the likes of modern CWC divers, so luminova is my best guess.
As others have said, test the glow and see what happens.
My bet is on later service luminova hands.
If your arm glows in the dark it’s tritium.
Sorry, couldn’t resist it...
Simon
Shouldn't the central seconds hand have a small arrow tip?
Yes, this seems to be the case as I left them overnight and viewed in a dark room - absolutely nothing.Quote:
Originally Posted by JasonM
There are some NOS tritium replacement hands on eBay for circa £300 but I'm not sure if that would be a wise move.
Sent from my SM-G950F using Tapatalk
That would be the case for most/all Tritium hands too. The 12.5 year half life has expired on most.
Quote:
Originally Posted by simonsays
Just in case there is anyone in doubt, 12½ years isn't a cut-off time. The lume should be present for many more years in proportion to activity of the Tritium as it decays:
However, the phosphor will also degrade with time and make the situation worse. There is more in a previous thread: How long can tritium lume last?
In particular, the OP may be interested in:
Quote:
Originally Posted by bobc
As I understand it, (and whether the science is true or not I don’t know) the phosphorous used in certain Tritium mixes notably that in old Omegas will charge under light. 1970,80,90 Rolex will not. I have not seen any Tritium hands that will hold charge independently for more than a miniute or so. The Tritium is effectively dead. Luminova will go for quite a while.
That graph looks to have errors on the x axis to my eye. It should continue to jump in 12.5 year increments, not double like that for that curve. It is clearly wrong at 49, 98 years and upwards. While some active tritium remains indefinitely, in practice after 2 half lives ie 25 years there isn’t sufficient activity left to excite the phosphor in any meaningful way so the lume can be considered dead.
Quote:
Originally Posted by PickleB
You're right, it's a crap graph...sorry about that. Here's a better one:Quote:
Originally Posted by Padders
As for 25% of the original activity not being enough to excite the phosphor, I'd have to ask why. If the phosphor were fresh I'd simply expect it to be a quarter as bright (probably not very useful, but not dead). I suspect (but don't know) that degradation of the phosphor plays a significant role. That's for Tritium paints, I'm not sure whether the same is true of GTLSs. I've still got 10 years to go before I can report if my Traser watch is still glowing (albeit very weakly) after two half-lives.