Knuckle-dragger question about tritium sights

Is there anything aside from a broken tritium vial that can cause night sights to stop glowing?


How old are they? Tritium is a radioactive isotope. I don’t know it’s rate of decay, but after several years it will probably lose it’s brightness.


Time. Tritium are really only good for about 10 years mebby 15 on the outside. As @Levi2 said it is radioactive and they do decay, the process of decay is what give off the light (actually it is a beta emitter with very low energy) , I want to say the half life is 12 . something years.




It sounds silly, but if you have the sight outside or under a light, does it glow more?

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I should’ve mentioned both of the sights in question are brand new.

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From what I found…I believe coated on the inside of the vial is a photoluminescent compound. The luminous compound is activated by the tritium, so you shouldn’t have to charge it. If you charge the light source with a light and it glows, the compound works, but there is insufficient decay to keep the compound activated. Basically, this would mean the initial electron activity of the tritium was low, or the tritium is old in it’s “lifespan”. Also, there is no law or standard for the birthyear to be noted on the vial.


I believe the age. Once they get more than 10 years old they glow less.

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Lifespan is roughly 12 years. My 15yo ones still glow a little…

There may be a date code on the side which might indicate when they were made. Trijicon ones usually have it. If they are “new”, and they are not bright, then they would be defective.


@MarkinMT is correct. The half life of tritium is ~12.3 years, and full life of ~24 years. If the tritium was pulled, the vial assembled, and you bought it on the same day, you would get the full years use. However if the vial sat assembled on a shelf 5 years before it was put in a sight, another year before you bought it and had it installed, you would only get ~6 years of use before the 50% mark.


Those you need to “charge” are an old phosphor (sp) type that will glow for a while after exposure to light. Tritium glows all the time. You will not seethe tritium effect unless it is DARK. Then it will be glowing little dots. As noted, the glow will gradually diminish as the sights age.

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