For those of you unsure of what tritium is, have a look at the wikipedia link for tritium.
"Tritium illumination is the use of gaseous tritium, a radioactive isotope of hydrogen, to create visible light. Tritium emits electrons through beta decay, and when they interact with a phosphor material, fluorescent light is created, a process called radioluminescence."
Tritium markers provide a futuristic glow, which I find helpful to locate my keychain or flashlights in low lighting conditions. They can come in a variety of colours, I find they can be decorative, looking quite pretty and 'cool'. Do note, certain colours will be less bright than other other colours. The following chart indicates the relative brightness levels of various colours.
Tritium markers are self illuminating, it does not need a power source, nor do they need to be 'charged up' with light (as with normal glow-in-the-dark items). They will continually provide their illumination for many years. The half life of tritium is 10-12 years, which means after 10-12 years it will be half as bright.
Do be aware, tritium does emit a small amount of beta radiation, however the amount of radiation produced is considered very minor and is unlikely to affect your health. Have another look at the wikipedia entry for more information on this, here is an excerpt:
"Tritium presents no external radiation threat when encapsulated in non-hydrogen-permeable containers due to its low penetration depth, which is insufficient to penetrate intact human skin. The primary danger from tritium arises if it is inhaled, ingested, injected or otherwise absorbed into the body. This results in the emitted radiation being absorbed in a relatively small region of the body, again due to the low penetration depth. The biological half-life of tritium—the time it takes for half of an ingested dose to be expelled from the body—is low, at only 12 days. Tritium excretion can be accelerated further by increasing water intake to 3-4 liters/day.
Direct, short-term exposure to small amounts of tritium is relatively harmless. If a tritium tube should break, one should leave the area and allow the gas to diffuse into the air. Tritium exists naturally in the environment, but in very small quantities."
Despite the reassurances that it is safe, if you are truly paranoid about the minor radiation released, you could consider keyfobs filled with glow powder instead. However, these glow-powder keyfobs/markers, need exposure to light in order to be 'charged up'. They can initially be brighter than tritium, but with time the luminescence will fade. I find after an hour (or even less), the tritium will be brighter than the glow-powder keyfobs.
You can buy these tritium markers/keyfobs from a variety of places. Ebay, online websites, and through sellers on cpfmarketplace.com. Most tritium markers come packaged and ready to use. You can also buy the tritium vials on their own (available in various sizes), and it is possible to install these vials, yourself, into clear empty keyfobs (sold separately). Some flashlights have milled tritium slots, to allow you to install a tritium vial into the flashlight body. A popular 'glue' to install these vials is norland 61. It sets very clear and does not change colour or fog with time. A UV source is required to accelerate the set of norland 61.
Here is a current photo of my of tritium markers.
They are listed as follows from left to right:
-small betalight kit marker (green)
-merkava II tritium glow-ring (green)
-self installed 23x3 tritium in clear case (white)
-self installed 23x3 tritium in clear case (green)
-rainbow keychain marker
-clear case nite glow-ring (blue)
-green case nite glow-ring (green)
-blue case nite glow-ring (blue)
'standard' nite glow-rings
These comes in green, blue or pink casing. They can be bought from cpfmarketplace, ebay, other online sources
'Special' clear-casing nite glow-rings
These come in a clear case instead of the coloured cases. I believe these are a special edition that can only be found through 'merkava' at cpfmarketplace. As these cases are clear, they are meant to allow more light through than the coloured cases. In my opinion this difference is minimal, and I actually prefer the more colourful cases myself. I believe they come in 5-6 different tritium colours.
Small betalight kit marker
I bought these from ebay. I believe they come in a variety of other sizes and colours. As the tritium contained with this marker is fairly small (5mmx1mm), it is not as bright as the others. It is significantly smaller than the nitek markers.
Merkava II tritium glow-ring
These are assembled by merkava at cpfmarketplace. They are relatively diminutive in size, and the 23x3mm tritium contained within is fairly bright. If you look at the photo, you can tell it has not help up very well on my keychain. It has become heavily scratched and a crack has developed, this is only after 7-9months of usage.
'Rainbow' keychain marker, cast within acrylic
These feature tritium vials, manually cast in acrylic. They are hand made by iknitsteel at cpfmarketplace. However he is no longer making them until further notice. Check out his thread for some of custom jobs he has done, they are quite amazing. Another maker (mattrg), has taken up the void iknitsteel has left... I can not comment on the quality of mattrg's work as I have not personally bought from him yet.
|As you can see there is limited illumination from the side profile|
As these are made to order, they are customisable; you can have various colours and multiple tubes of tritium. The one I have consists of 5x1mm tritium vials of seven various colours. I find this version aesthetic and colourful, however it does not provide the best illumination when viewed on the profile shot. In my opinion a 23x3mm tritium source provides better illumination.
23x3mm tritium vial self installed in clear acrylic case
I bought the tritium vial from merkava, the clear acrylic case from LESLIEx317537, the norland 61 from RocketTomato; all from cpfmarketplace. At the moment this is my tritium keyfob of choice. It is slightly wider than the merkava II marker, however I find it more robust and does not scratch as easily. It does take some effort to order the items separately, and glueing the tritium into the clear case, does take some practice and forethought. If you want something ready and pre-made, this is not for you.
This list is far from complete, you may find other various versions of tritium markers from other online sources (often hong kong based websites that also sell flashlights). Tritium vials are sometimes used in fishing, and you may find them available at some fishing websites (e.g. tritium-max betalight). There are some makers who offer tritium encased within a titanium shell (e.g. bart, farid, g1k).
CPFmarketplace forum with sales threads of previously mentioned sellers:
TiGlow from bart
Steve Ku's sales thread on cpfmarketplace dealers corner: