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Discussion Starter · #21 ·
Fantastic review!

I wonder if you can say the T100 tritium would stay brighter longer (over 25 years) than the T25. Certainly would be another good reason to go T100.
Well, I cannot say for sure, but physics dictate that after 24.6 years (based on the half-life of Tritium at 12.3 years) the T100 would have 1/4 its activity, or the equivalent of T25.

So, yes. I expect the T100 tubes to stay brighter longer.

HTH
 

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Great work. Thank you very much for taking the time to perform this test and post the results.

I recently bought the GSAR (actually MSAR) with the specific requirement for long lasting lume for camping purposes. Although some of the luminova shots are visually appealing, functionality was my primary concern. I am happy to see that tritium has not diminished very much (if at all) on the older tubes.
 

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Discussion Starter · #24 ·
Great work. Thank you very much for taking the time to perform this test and post the results.

I recently bought the GSAR (actually MSAR) with the specific requirement for long lasting lume for camping purposes. Although some of the luminova shots are visually appealing, functionality was my primary concern. I am happy to see that tritium has not diminished very much (if at all) on the older tubes.
Thanks, you're welcome.
 

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Well, I cannot say for sure, but physics dictate that after 24.6 years (based on the half-life of Tritium at 12.3 years) the T100 would have 1/4 its activity, or the equivalent of T25.

So, yes. I expect the T100 tubes to stay brighter longer.

HTH
Actually, it would depend on how they get to 100 mCi.

The 25 or 100 mCi is the measure of how much radioactive material is present in the watch. It can be increased by making the tubes larger so they hold more 3H, or you can put more "regular" sized tubes on the dial.

If you used the same size and type of tubes as on a 25 mCi watch, but put four times as many, the individual tubes would dim at the same rate as before. Although, the cumulative glow would remain four times as bright.

If you use tubes that hold four times as much radioactive material, the tubes would remain brighter than their smaller cousins.

Just and aside - a T25 watch containing 25 millicuries material has 0.000 0025 grams* in its 14 or 15 gas tubes.

_______________________
* or 0.0025 mg (milligrams)
or 2.5 μg (micrograms)
 

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Nice, nice job. As an owner of Luminox & Ball, as well as several conventional lume watches, this confirms my casual observations. In particular regarding tubes whose age are approaching the half-life of tritium. Even though they are noticably less bright than when new, they still easily outperform standard lume after less than an hour of darkness. Well done.
 

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Discussion Starter · #28 ·
Actually, it would depend on how they get to 100 mCi.

The 25 or 100 mCi is the measure of how much radioactive material is present in the watch. It can be increased by making the tubes larger so they hold more 3H, or you can put more "regular" sized tubes on the dial.

If you used the same size and type of tubes as on a 25 mCi watch, but put four times as many, the individual tubes would dim at the same rate as before. Although, the cumulative glow would remain four times as bright.

If you use tubes that hold four times as much radioactive material, the tubes would remain brighter than their smaller cousins.

Just and aside - a T25 watch containing 25 millicuries material has 0.000 0025 grams* in its 14 or 15 gas tubes.

_______________________
* or 0.0025 mg (milligrams)
or 2.5 μg (micrograms)
Excellent points.

As can be seen in the first few shots in my OP (the 15, 30 and 45 minute shots), the T100 watch in the lower right has tubes that are much larger and much brighter than the T25 watches.

This makes me feel safe in suggesting that this style T100 watch will indeed remain brighter longer.

HTH
 

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Great test, thanks very much. I've always been curious about the actual vs. theoretical performance of tritium "long" term.
 

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Actually, it would depend on how they get to 100 mCi.

The 25 or 100 mCi is the measure of how much radioactive material is present in the watch. It can be increased by making the tubes larger so they hold more 3H, or you can put more "regular" sized tubes on the dial.

If you used the same size and type of tubes as on a 25 mCi watch, but put four times as many, the individual tubes would dim at the same rate as before. Although, the cumulative glow would remain four times as bright.

If you use tubes that hold four times as much radioactive material, the tubes would remain brighter than their smaller cousins.

Just and aside - a T25 watch containing 25 millicuries material has 0.000 0025 grams* in its 14 or 15 gas tubes.

_______________________
* or 0.0025 mg (milligrams)
or 2.5 μg (micrograms)
This is the correct statement. There is no such thing as a T100 tube in a watch. The T100 designation refers to total tritium, not an individual tube. Ball is licensed by the NRC to import T100 watches. If there was a T100 tube, a Ball watch could legally only contain one such tube. What you are seeing are actually double tubes which even a T25 watch could have...only less of them. The size, color and gas pressure of the tubes all affect real and/or perceived brightness.
 

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Bravo, gaijin--this is a very useful test to see. Thank you for taking the time to do it and post the results here. :-!


Given how Tritium has a relatively short life, you'd figure that they would either design the tritium tubes in such a way as to have a miniature valve for "refilling" by an authorized service center, or a special kind of tube holder that allows for release/replacement without significant effort. But apparently each watch maker has their own way of dealing with it. Unfortunately there is no standard tube design. I know Ball has a service for doing the tritium replacement that is, from what I read once, about $100. I don't know if they simply swap out the dial and hands then recondition the ones with the old tubes for future replacements, or actually do the vial replacement on your specific watch dial and hands.


Anyway, has anyone done this kind of test with just lume adorned watches? I'm curious to know which ones last the longest and which ones were below average.
 

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Discussion Starter · #35 ·
Bravo, gaijin--this is a very useful test to see. Thank you for taking the time to do it and post the results here. :-!

Anyway, has anyone done this kind of test with just lume adorned watches? I'm curious to know which ones last the longest and which ones were below average.
Thank you, and you're welcome.

Food for thought - which exemplar conventional lume watches would you like to see (limit to 10)?

Not hard to do ...
 

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Great test! My very-old mb microtec (I'm guessing it's around 15 years old) has much dimmer tritium glow than my new Luminox 1402, but both always spank all my others, including my new (6 months) Christopher Ward C5 MkII with "superluminova". The reason: I essentially always have long sleeves on. Watches never get charged.

That's the main reason I bought the Luminox; the CW is a nice watch, but utterly useless to me in a dark bar, while watching a play or movie, or to check the time in the middle of the night.
 

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Thank you. Glad you enjoyed it.
Amen brother! The T-100 ROCKS!! I've been a tritium freak for years starting with my first Marathon "field" watch that was issued to me in the Army. I then got on the Luminox bandwagon (still on it) but the new Deep Blue T-100's rule the roost for sure! I sold 4 of my T-25 tubed watches after getting my 2 DB T-100 watches because they are SO MUCH brighter that I didn't want to wear the others anymore! I did keep a few though because of their good looks (IMO) like my Tawatec watches and my 12 year old 3001 Luminox. I'm keeping the Luminox just to see how long the tritium does last, so far it's been 12 years and it has faded some compared to my newer models but I have to have dark adjusted eyes to tell!! It surely hasn't lost HALF of it's potency IMO??
 

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T-100s seem to be the way to go...why not? Brighter, bright longer.
 

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...I'm keeping the Luminox just to see how long the tritium does last, so far it's been 12 years and it has faded some compared to my newer models but I have to have dark adjusted eyes to tell!! It surely hasn't lost HALF of it's potency IMO??
The commonly stated "the half life is 12 years so it will be half as bright in 12 years..." bit is based on an inexact understanding of how radioactive luminous materials work.

It is true that after 12 years half of the original tritium will have decayed to helium, but that does not mean the glow will necessarily be half as bright.

The obvious question is: Is all the original energy of decay being used to produce glow? Surely, the amount of zinc-sulfide will govern this, it can only absorb so much energy. So, first the tritium must decay to the point where the energy output is equal to the energy absorption of the zinc-sulfide before decay will cause a drop in light output.

Then the next question is: Is the total energy output of the tritium really proportional to the light output. I don't know for sure, but it may not be.

Then the date the tritium was produced, the date the vials were produced and the date the watch was placed in your hands all have a major affect on "initial brightness," and the total length of useful life. Military compasses require that the tritium vials be installed on compasses within a few months (60 days, I believe) in order to maximize life, but this does result in higher production costs.
 

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I have the same purpose in mind but after trying out some regular lume watches it looks like I may have to go the trit tube route to get that all night lume and ease of reading the time. My crummy eyesight struggles to make out the time when it's 4-5 a.m. in the morning with regular lume.

This thread certainly makes the case for T-100 tubes but it begs the question if someone uses those in a field style quartz watch. I'd rather have quartz, in this case, for banging around outdoors. I don't really need the added bulkiness of a bezel but would make do if it's the only option. T-100 Deep Blue watches are all mechanical, not to mention pricey and large.

P.S. Thanks having the patience and taking the time to do this test

Great work. Thank you very much for taking the time to perform this test and post the results.

I recently bought the GSAR (actually MSAR) with the specific requirement for long lasting lume for camping purposes. Although some of the luminova shots are visually appealing, functionality was my primary concern. I am happy to see that tritium has not diminished very much (if at all) on the older tubes.
 
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