[dbostedo]

That means 12.3 years from now, the tritium lume brightness will be half what it is today.

Well, it means that the amount of radioactive tritium will be half of what it is today. I'm still not certain the it means the lume brightness will be half. And this might be more of an academic/theoretical concern... but...

I think I asked this in another thread, but does anyone know if it takes ALL of the initial radioactivity to reach some maximum brightness? Or is there "excess" radiation initially in the tubes? Do radioluminescent materials "max out" in brightness, or get continually brighter with more radiation?

 

[MX793]

Well, it means that the amount of radioactive tritium will be half of what it is today. I'm still not certain the it means the lume brightness will be half. And this might be more of an academic/theoretical concern... but...

I think I asked this in another thread, but does anyone know if it takes ALL of the initial radioactivity to reach some maximum brightness? Or is there "excess" radiation initially in the tubes? Do radioluminescent materials "max out" in brightness, or get continually brighter with more radiation?

I'm not sure brightness (candelas, lumens, whatever) is necessarily linearly related to the amount of radioactive material present.

Additionally, how the eye perceives brightness is not linear. It's more logarithmic. If you reduce the amount of light (candelas) from a source to half, the human eye generally does not register the source as half as bright. It would appear dimmer, but brighter than half.

 

[andycoulson1.ac]

I'm not sure brightness (candelas, lumens, whatever) is necessarily linearly related to the amount of radioactive material present.

Additionally, how the eye perceives brightness is not linear. It's more logarithmic. If you reduce the amount of light (candelas) from a source to half, the human eye generally does not register the source as half as bright. It would appear dimmer, but brighter than half.

I think we went through this in detail in an older thread. I think it may even have been you who I discussed this with. I think we found several scientific papers on the matter and concluded that if you are really interested in how it is perceived it is impossible to say but depends on colour, ambient light, how adjusted your eyes are to the ambient setting, and maybe a couple of other things.

I don't think there is 'excess' radiation when new. I also think there is some complicated maths about the radiation being blocked by the hydrogen in the vial, and also any other gasses present. It all got very complicated and there were lots of graphs. Also there will be tritium escape through the side of the container (very very small amounts).

I think your perception of light levels differ also dependent on your mental and emotional state. It is impossible to say one thing looks 50% as bright as something else. That is a meaningless statement. You can only say something looks lighter or darker.

If my memory is correct it is far too complicated to say for sure, and all we can say is that it gets less bright over time, but we are talking years (not months or decades) before you notice a change.

 

[dbostedo]

I think we went through this in detail in an older thread. I think it may even have been you who I discussed this with. I think we found several scientific papers on the matter and concluded that if you are really interested in how it is perceived it is impossible to say but depends on colour, ambient light, how adjusted your eyes are to the ambient setting, and maybe a couple of other things.

I don't think there is 'excess' radiation when new. I also think there is some complicated maths about the radiation being blocked by the hydrogen in the vial, and also any other gasses present. It all got very complicated and there were lots of graphs. Also there will be tritium escape through the side of the container (very very small amounts).

I think your perception of light levels differ also dependent on your mental and emotional state. It is impossible to say one thing looks 50% as bright as something else. That is a meaningless statement. You can only say something looks lighter or darker.

If my memory is correct it is far too complicated to say for sure, and all we can say is that it gets less bright over time, but we are talking years (not months or decades) before you notice a change.

Those are good points, and the eye/brain are always adjusting and compensating for various factors. But you could take people out of it, and just measure the light level as a starting point. I'd just be curious to see the measured light output of a tritium tube when it's brand new, vs 12 years later. How someone actually perceives that light is a bit different question (that I'd also like the answer to, but would be harder to get I'd think).

 

[andycoulson1.ac]

Those are good points, and the eye/brain are always adjusting and compensating for various factors. But you could take people out of it, and just measure the light level as a starting point. I'd just be curious to see the measured light output of a tritium tube when it's brand new, vs 12 years later. How someone actually perceives that light is a bit different question (that I'd also like the answer to, but would be harder to get I'd think).

The decrease in light emitted over 12.32 years (the half life of tritium) is actually greater than half, because the phosphorous coating of the tube degrades slightly too. I think there are other small effects, but in general the absolute amount of light energy emitted will be just less than half of when new.

I did dig out multiple scientific papers and a study by manufacturer for an old thread, but it was with an old account and I can't locate it now.

 

[mkfarin]

I've been asking about tritium on here and most people recommend not to purchase it as it dies down in about 10 years and some don't replace the vials. What other products are out there that will illuminate say for a night out (maybe 7 hours or more) and also last longer than 10 years?

A couple of folks have said you can buy it out there. Where and under what market name?

 

[Charlie_Kilo]

A couple of folks have said you can buy it out there. Where and under what market name?

For DIY, Amazon & eBay to name a few. Problem is finding the exact size you need, assuming these are intended for a watch.

The other alternative is to send your watch to Bonding Co. LTD in Hong Kong and have them re-lume your watch. They are legit. As of earlier this year, cost was $190 plus return shipping.

 

[mkfarin]

For DIY, Amazon & eBay to name a few. Problem is finding the exact size you need, assuming these are intended for a watch.

The other alternative is to send your watch to Bonding Co. LTD in Hong Kong and have them re-lume your watch. They are legit. As of earlier this year, cost was $190 plus return shipping.

Wow thank YOU for the info. A really great idea.

 

[MissileExpert]

Well, it means that the amount of radioactive tritium will be half of what it is today. I'm still not certain the it means the lume brightness will be half. And this might be more of an academic/theoretical concern... but...

I think I asked this in another thread, but does anyone know if it takes ALL of the initial radioactivity to reach some maximum brightness? Or is there "excess" radiation initially in the tubes? Do radioluminescent materials "max out" in brightness, or get continually brighter with more radiation?

"Max" depends on the amount of radioactive tritium loaded into the tube and the concentration per volume of the tube. The amount of tritium in a 0.1 ml tube will appear much brighter than if it were loaded into a 1.0 ml tube.

The level of lume decreases in a geometric fashion, since the amount of tritium is reduced by half every 12.3 years. At 12.3 years, the lume level would be 50% of time zero, but at 98.4 years (4 half lives), the lume level is 6.25% of the time zero lume level. The amount of lume is determined by the amount of remaining radioactive tritium. Whether it's still useful as lume is a combination of where you start with and how sensitive your eyes are to the wavelength of light emitted and how sensitive your eyes are to light.

 

[dbostedo]

"Max" depends on the amount of radioactive tritium loaded into the tube and the concentration per volume of the tube. The amount of tritium in a 0.1 ml tube will appear much brighter than if it were loaded into a 1.0 ml tube.

The level of lume decreases in a geometric fashion, since the amount of tritium is reduced by half every 12.3 years. At 12.3 years, the lume level would be 50% of time zero, but at 98.4 years (4 half lives), the lume level is 6.25% of the time zero lume level. The amount of lume is determined by the amount of remaining radioactive tritium. Whether it's still useful as lume is a combination of where you start with and how sensitive your eyes are to the wavelength of light emitted and how sensitive your eyes are to light.

I get all that, but I'm still not sure I have an answer, though @andycoulson1.ac provided his take from prior digging.

What I'm asking is more about the radioluminescent material lining the tubes. Does that material max out, and is there a chance it's maxed out when a tube is new? In other words, if I took an existing brand new tube, and doubled the amount of tritium in it, is it capable of getting twice as bright, and would it?

 

[Sokpuppet1]

Maybe a stupid question—are there watches that use both Tritium and Superluminova, to capture the benefits of both? Heck, add Indiglo and you’ve got a watch that’s ready for the blackest night.

 

[MX793]

Maybe a stupid question—are there watches that use both Tritium and Superluminova, to capture the benefits of both? Heck, add Indiglo and you’ve got a watch that’s ready for the blackest night.

I've seen tritium indices combined with SLN on bezels. Can't say I've seen tritium indices combined with SLN lume plot indices.

 

[Earthbound]

There is no comparison. Certainly tritium is way better throughout the night. Why anyone defends lume is beyond me. That being said, yes in 20years it will have to be replaced. If that’s too much effort to put forth down the road, don’t buy a watch with it. I view it this way. In twenty years I would have to service my Rolex 2x at a cost of $800 each time and not have the watch for a couple months each time. That sounds like quite a sacrifice yet people still love their Rolexes!

 

[MissileExpert]

I get all that, but I'm still not sure I have an answer, though @andycoulson1.ac provided his take from prior digging.

What I'm asking is more about the radioluminescent material lining the tubes. Does that material max out, and is there a chance it's maxed out when a tube is new? In other words, if I took an existing brand new tube, and doubled the amount of tritium in it, is it capable of getting twice as bright, and would it?

I understand now. It depends on the lining they use, but some phosphorescent compounds will wear out over time. The MB-Microtec tubes (Ball, Traser, Marathon, etc) use Zinc Sulfide as the coating. It's hard to say what life it has. UV exposure from sunlight probably has a greater effect on life than the tritium radiation.

There is a theoretical max brightness. If the phosphorescent coating is completely excited by tritium, then that's your max brightness. Whether you get to a max brightness is a function of how much tritium and how much coating is present in the tube.

 

[chopy_ro]

I've been asking about tritium on here and most people recommend not to purchase it as it dies down in about 10 years and some don't replace the vials. What other products are out there that will illuminate say for a night out (maybe 7 hours or more) and also last longer than 10 years?

Well, nothing beats LED ! 😜😜
Jokes aside, C3 Superluminova is a good option.

 

[dbostedo]

Whether you get to a max brightness is a function of how much tritium and how much coating is present in the tube.

Yep - that's exactly what I'm curious about...

 

[Mark Greenman]

Tritium is where its at for all night lume.

This is probably the best video on it. Basically, C3 starts out WAY brighter then Tritium, but within 20 minutes after charging, it has degraded to the level of Tritiums brightness. After 20 minutes, the C3 is continuing to dim...while Tritium is remaining at constant brightness. Go to bed at 11pm and wake up at 4:37am, there will be no comparison...the Tritium is quite bright. Not only has the Tritium not faded, but now your eyes, having just awoken in the dark, are very sensitive to light, making the Tritium seem all the brighter.

One aspect thats often overlooked is 'out and about at night' brightness.

When out and about (work, bars, theaters, play, driving) one is not sitting around charging up their watch with UV light. Its simply being passively charged from any ambient light. And at night, this passive charging breaks down.

Leave my moderately lit house 7pm, drive 30 minutes in my dark car to my favorite bar across town to meet a friend...already the C3 watch is pretty dim. Spend 2hrs in a dim bar before going to a dark nightclub... C3 will be dead, whereas Tritium will be totally visible.

That scenario mixes and matches pretty easily. Camping and going on a night hike after cooking over the campfire? Driving to Dinner then a movie? Visit to the theater followed by late dinner? Driving from LA to Vegas at night? Theres many scenarios where one is out at night, without the practical ability to be charging a C3 watch.

These are the times where Tritium really shines. No matter what or when, if its dark, you can read a tritium watch.

 

[INAMINUTE]

Tritium is where its at for all night lume.

This is probably the best video on it. Basically, C3 starts out WAY brighter then Tritium, but within 20 minutes after charging, it has degraded to the level of Tritiums brightness. After 20 minutes, the C3 is continuing to dim...while Tritium is remaining at constant brightness. Go to bed at 11pm and wake up at 4:37am, there will be no comparison...the Tritium is quite bright. Not only has the Tritium not faded, but now your eyes, having just awoken in the dark, are very sensitive to light, making the Tritium seem all the brighter.

One aspect thats often overlooked is 'out and about at night' brightness.

When out and about (work, bars, theaters, play, driving) one is not sitting around charging up their watch with UV light. Its simply being passively charged from any ambient light. And at night, this passive charging breaks down.

Leave my moderately lit house 7pm, drive 30 minutes in my dark car to my favorite bar across town to meet a friend...already the C3 watch is pretty dim. Spend 2hrs in a dim bar before going to a dark nightclub... C3 will be dead, whereas Tritium will be totally visible.

That scenario mixes and matches pretty easily. Camping and going on a night hike after cooking over the campfire? Driving to Dinner then a movie? Visit to the theater followed by late dinner? Driving from LA to Vegas at night? Theres many scenarios where one is out at night, without the practical ability to be charging a C3 watch.

These are the times where Tritium really shines. No matter what or when, if its dark, you can read a tritium watch.

I have many watches with great lume, and only one with Tritium tubes. My Davosa Argonautic Lumis with Tritium kicks the other's ar5es

 

[WanderingFool]

This was recently discussed on another thread. Personally, tritium is a loser for me. I have an Armoirlite that is eight years old and is is drastically less bright. Those that say it’ll have to be replaced in 24 years I think are overly optimistic by at least 12 years. On a recent thread someone posted that Ball quoted $20 per tube which would cost him about $1000 on his watch. Regardless, ran into this new watch...

LEDs on all the time and apparently battery lasts three years.

 

[Mark Greenman]

I have many watches with great lume, and only one with Tritium tubes. My Davosa Argonautic Lumis with Tritium kicks the other's ar5es

Thats a cool model, I didn't even know there was a nice tritium swiss diver other then Marathon.