I know I could look up the answer on the web, but I thought it was a good Forum topic....I have wondered.....
Suppose an AD has two IWC AT 2000 watches. One is placed in the store window and receives a good dose of direct sunlight every day. Another is placed in the safe and is never removed from it's box.
After a year both watches are sold. Does the Aquatimer which resided in the safe have more lume than its sunburned brother? Is there any difference? Should there be a difference?
Hello Alan,
This is indeed a very nice question. I found the answer on Wikipedia:
For those who don't want to read the entire article: This activation and subsequent light emission process can be repeated again and again, and the material does not suffer any practical aging.
You do realise though that your question is higly hypothetical. I don't think any AD would have a IWC AT 2000 in the store window for a year :-)
Kind regards,
Clemens
I guess the question is - what causes SuperLuminova to decay over time, if at all...
from an earlier post:
i think this was Michael's response: www.iwc.com/forum/en/discussion/1589/
"Super-LumiNova® vs. tritium
Science wasn't my best subject at school, so I stand to be corrected here by our chemists and physicists.
However, it is my understanding that Super-LumiNova® doesn't have a life (it continues indefinitely) and is not radioactive, but it does have to be "charged" by light to be activated, will not glow as long as tritium after a charge, and can appear green-ish. However, it can be much brighter than tritium --which for some people is great and to others is an unnecessary distraction.
Super-LumiNova® is a relatively new development and is made of photoluminescent crystals (anorganic pigments) which operate like a "light battery". Foreign atoms built into the crystals act as activation, storage and luminous centers.. The more intensive and the longer the activation or "charging" lasts, the more electrons are lifted up. After a storage phase these electrons fall back to the ground level and emit the energy loss in form of visible light
Super-LumiNova® pigments are free of any radioactive substances. After sufficient activation by sunlight or artificial light Super-LumiNova® crystals emit light in the dark and remain visible for an entire night. This activation and subsequent light emission process can be repeated indefinitely, and the material does not suffer any aging.
Tritium, on the other hand, is an unstable isotope of hydrogen. Tritium’s half life is approximately 12.3 years and it decays at a rate of approximately 5.5 percent per year (very technically, every year 5.5% of the parent H3 (Tritium) decays into the daughter He3 (Helium-3)). This is why watch dials and hands using tritium “wear out”.
It is my understanding this this decay causes phosphor to "excite", producing luminesence. While as a practical matter this can be safe, in extremely large quantities or if ingested, tritium is considered a carcinogen.
There's advantages to both, but I suspect tritium will be soon be gone...not just for iWC, but generally."
I have read at various watch forums too that there is 'no sufficient data that Superluminova decays over time" or the like...
as an aside, I think this is a very interesting and useful website, although I cannot as yet vouch for its accuracy:
Thanks guys. I used the AT as the example because I think it is entirely possible that a dealer could have an inventory of 10 watches with one watch assigned to the window while all the others are sold over time and inventory replaced.
Perhaps I should have used my DFB Doppel as an actual example as I was told by the store owner in Vienna that they had two watches for sale. One had been in the window for close to a year before it was sold. My watch then replaced it and I bought it a few months later.
Maybe the better question would be what effect the heat from the sun through glass would have on watch oils over time?
I guess the answer would be that the oils would dry up faster, and thereby making the watch go faster ?
Cellar asked this a while ago too: www.iwc.com/forum/en/discussion/23077/?page=4
[b][i]Save for the hottest days?
47.1C/116.8F here yesterday and today will be the fourth day over 40C. Anything with a bracelet takes time to cool down once you get out of the heat.
I know IWC test there oils to 60C but I do wonder how long the oil stays on parts when the temperature is at consistent high temperatures.
Cheers from the cellar
[/i] [/b]
Hello Alan,
My guess is that a watch in a window store would age more than a watch in a cool box in a safe. Straps and maybe the dial will also suffer from the radiation of the sun and could change color. I have seen that IWC performs tests to advance the ageing process and see what the effects are on the watches.
The glass of the window store and the crystal on the watch will block all UV radiation but the watch may get warmer due to the sunlight.
Kind regards,
Clemens
well i got my Aquatimer chrono back in april. but i notice my Lume only last about 1hr.. and it starts to get really weak.. and after about 2hrs.. it is quite dark... how long is it suppose to last???
Several questions (superLuminova), (oil at different temperature) have been answered extensively. Just a few additions.
The time that the lume consisting of SuperLuminova glows in the dark is limited to a few hours, because as explained it has to be turned on by a light source. For Tritium this is different. The lume is continuously emitting light but after a bit more than 12 years ( half time life of Tritium), the glowing in the dark has been reduced to 50%, making it hardly possible to read the watch at night. Tritium is a gas (H3) that can escape from the watch by vaporisation. It is radioactive but relatively harmless compared to the Radium-226 lume that has half life time of 1600 years. Radium and Tritium loaded watches are not produced anymore and also for repair IWC uses only the non-radioactive SuperLuminova.
With regard to the lubrication of the watch movement at extreme temperatures, it is clear that the oil has to withstand more than in regions with average temperatures. But there is more. The balance spring and balance wheel will expand and shrink at extreme temperatures, making the watch less accurate. With the arrival of special alloys in which iron and steel were avoided for a great part, the watch industry especially in Switzerland developed alloys such as Nivarox for the balance spring and Glycodur for the balance wheel. These alloy metals did hardly expand or shrink between minus 20 ° and plus 40 ° Celsius. Moreover, their sensitivity to magnetic forces was extremely reduced as well. Paillard, Guillaume and Straumann were the leading scientists to develope these metals now nearly a century ago.
Special about the IWC vintage Ingenieurs from the 1950-60ties is that IWC used the maximum possibilities to produce watches that were extremely accurate and a-magnetic, by chosing the best available materials and solutions to make an Ingenieur extremely accurate. To study the details of this, which I did, is extremely interesting and revealing.
Kind regards,
Adrian,
(alwaysiwc).