Forums Latest Auctions Members

How do you tell if replacement hands are later tritium, or superluminova?

  1. rcs914

    rcs914 Mar 5, 2018

    Posts
    1,770
    Likes
    2,287
    So I realize that at least the minute and hour hands on my 145.022-76 are replacement, but what I've been unable to determine is if they are superluminova, or if they are tritium hands that are from the late '80s early '90s. What's interesting is that all three hands appear to be the same "whiteness" but when you hit the dial with a blacklight the chrono hand intensity and drop off matches the dial, not the hour and minute hands. For the chrono hand and the dial the glow fades after about 30 seconds. For the hour and minute hands it takes about 10 minutes. Because the glow still fades quickly (basically totally gone after 15 minutes) it makes me wonder if the hands are still tritium, but just much later production. Anyway, since any thread is useless without Pics, lets progress to those:

    Watch in normal light:

    20160520_131440_001.jpg

    Watch in direct sunlight:

    Speedmaster hands.jpg

    Immediately after 30 seconds of direct UV exposure:

    IMG_20180305_110149.jpg

    30-45 seconds after the above picture:

    IMG_20180305_110222.jpg

    A 30 second video showing the decay:



    And a shot after 10 minutes:

    IMG_20180305_111627.jpg


    Any thoughts?
     
    M'Bob likes this.
  2. Foo2rama

    Foo2rama Keeps his worms in a ball instead of a can. Mar 5, 2018

    Posts
    12,526
    Likes
    17,318
    HOur and minutes appear to be luminova. Tritium will sometimes hold a minor charge to about 30 seconds max. Maybe very very feint to about a minute max.
     
    M'Bob likes this.
  3. rcs914

    rcs914 Mar 5, 2018

    Posts
    1,770
    Likes
    2,287
    See that's what I've thought since I bought the watch, but I would think that luminova hands would hold a "charge" longer than 10 minutes. That last pic is quite dim in person - my pixel 2 autoset that exposure to f/1.8 1/15 sec at ISO 4800. But also they should always have some dim glow if any of the tritium was still active (ie if the hands were from 1990, they would be approximately 1/4 their original amount) but that wouldn't translate into a longer excitement period from UV exposure I don't think).
     
  4. Foo2rama

    Foo2rama Keeps his worms in a ball instead of a can. Mar 5, 2018

    Posts
    12,526
    Likes
    17,318
    Tritium does not take a charge like luminova. The decay of the Tritium lights up the compound. The compound will store a little bit.
     
  5. 10H10

    10H10 Mar 5, 2018

    Posts
    498
    Likes
    1,030
    How about a geiger counter close to the dial, that's what I do...
     
  6. COYI

    COYI Mar 5, 2018

    Posts
    335
    Likes
    363
    I thought geiger counters were only useful for detecting radium lume (not tritium)?
     
    timecube, rcs914 and Foo2rama like this.
  7. M'Bob

    M'Bob Mar 5, 2018

    Posts
    3,362
    Likes
    6,559
    Had a guy at a local hospital check my Tritium watches with a Geiger counter. No response.
     
    timecube and Foo2rama like this.
  8. rcs914

    rcs914 Mar 5, 2018

    Posts
    1,770
    Likes
    2,287
    I wonder if the tritium gas vials give off any detectable radiation? I'm guessing not.
     
    timecube likes this.
  9. Mouse_at_Large

    Mouse_at_Large still immune to Speedmaster attraction Mar 5, 2018

    Posts
    1,822
    Likes
    4,391
    I don't think it's quite that simple. To generate illumination, the tritium decay must react with a phosphor material. True, the half life of tritium is 12.32 years, but the drop-off in light produced is also affected by degradation of the phosphor material https://en.wikipedia.org/wiki/Tritium_radioluminescence
     
    Foo2rama likes this.
  10. Foo2rama

    Foo2rama Keeps his worms in a ball instead of a can. Mar 5, 2018

    Posts
    12,526
    Likes
    17,318
    No vials in anything but some luminox watches I think. Tritium from a 70’s Watch I doubt would read above background.
     
    Seaborg and timecube like this.
  11. wsfarrell

    wsfarrell Mar 5, 2018

    Posts
    1,934
    Likes
    2,769
    The hands look similar in the first photo, but the sweep hand looks a little darker than hour and minute in the second photo. Your glow test confirms with 95% certainty (to me) that sweep is tritium, hour and minute are luminova.
     
    BatDad and Foo2rama like this.
  12. rcs914

    rcs914 Mar 6, 2018

    Posts
    1,770
    Likes
    2,287
    That was sort of an aside, just wondering about if they give off anything detectable. You can get tritium gas vials in any number of ways. Ball watches for example have dials where they are lit up like a Christmas tree. My Prometheus Jellyfish also has tritium gas vials for the markers.
     
  13. rcs914

    rcs914 Mar 6, 2018

    Posts
    1,770
    Likes
    2,287
    Yeah, that's what I thought too. Just annoying that the hour and minute were replaced at some point in the past. Can't imagine there was any real need for it.
     
    Bryan likes this.
  14. M'Bob

    M'Bob May 21, 2020

    Posts
    3,362
    Likes
    6,559
    For those checking with a UV light: how long do you expose the luminous for during your test, and is using a UV light give different results from putting it under a focused and strong common light source?
     
  15. BatDad

    BatDad May 21, 2020

    Posts
    755
    Likes
    2,176
    Some signs I also look for on Luminova hands, aside from the black light test, - they appear to be consistently Super White, with a slightly greenish lume tinge.

    If I see anything that’s bright - I start to form the opinion - likely new and worth a closer look
     
    M'Bob likes this.
  16. SkunkPrince

    SkunkPrince May 21, 2020

    Posts
    98
    Likes
    73
    Tritium from 1995 even in a vial does not glow hardly at all.

    The Speedmaster is perhaps the worst of Omega's modern lines to have a glow worth a damn. That is one of the reasons I got rid of the Speedmaster I owned from the late 90s through about 2015. Lume sucked, even if it was Super Luminova.
     
    M'Bob likes this.
  17. BatDad

    BatDad May 21, 2020

    Posts
    755
    Likes
    2,176
    Seconds under the UV light. Doesn’t seem to need more.
    I haven’t noticed different decay rates, but my limited experience shows me it takes much longer to get a level of brightness using a ‘normal’ light source
     
    M'Bob likes this.
  18. M'Bob

    M'Bob May 21, 2020

    Posts
    3,362
    Likes
    6,559
    Also, looking at the photos above...I wonder if they're representative: under the UV light, does Tritium tend to glow Hulk green, whereas Luminova, that much lighter shade?
     
    BatDad likes this.
  19. timecube

    timecube May 21, 2020

    Posts
    388
    Likes
    473
    Tritium only decays via a single weak β, so the radiation is barely able to penetrate a few microns of lume, much less the crystal. Even fresh tritium won't show on a conventional Geiger counter. And its only decay product (deuterium) is stable.

    Radium OTOH emits α and γ, and most of its daughters are are also radioactive.
     
  20. BatDad

    BatDad May 21, 2020

    Posts
    755
    Likes
    2,176
    That’s consistent with what I’ve seen. Others who seen more watches will have more experience - but my observation is that it’s glaringly obvious.

    A $10 Blacklight torch does wonders. But can also confirm expensive mistakes :)

    My older relumes (prior to folks working out the tritium like formula) are very ‘messy’ under B/L
     
    M'Bob likes this.