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Radium - Geiger Counter Measurements

  1. Leica May 9, 2019

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    i can try on banana but i have no lead sheet.

    I test it on my 1980s rolex daydate , the reading was very low. i believe it has tritium on it
     
  2. jshaw083 May 9, 2019

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    To give you some context, here's Table 4 from GK Gillmore et al. (2012) from Environment International; 45: 91-81. He's the same professor from Kingston University who published the report that caused a resurgence in anxiety around radium watches in 2018 (see links below). As you can see, for wristwatches, measurements 2 cm above crystal usually range 0.5-20 uSv/hour range, with 20 uSv/hour being really atypical and high (it was a military watch from the 1940s).

    The articles posted below (Hodinkee, W&W, etc.) I believe are mainly sensationalist. The conclusion from the study is that the radiation levels are acceptable, particularly from later watches post-1950s and non-military watches. Pocket watches are larger and so more radium = higher risk. They concluded the emitted radon levels were the greater concern.

    https://www.hodinkee.com/articles/new-report-shows-radium-dials-might-pose-serious-danger
    https://www.northampton.ac.uk/news/wwii-military-watches-potentially-pose-serious-cancer-risk/
    https://wornandwound.com/new-study-warns-against-radium-dialed-watches/

    Table 4..JPG
     
    Edited May 9, 2019
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  3. Leica May 9, 2019

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    thanks for this data , i will need to test another radium watch to see the difference.
     
  4. AdInfinitum May 9, 2019

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    Yes, tritium lume is comparatively harmless :)

    It was handy of Blancpain to write the radiation limits on their vintage tritium FF "No Raditions" right on the dial...

    [​IMG]
     
  5. jshaw083 May 9, 2019

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    To be clear though....135 uSv/hour is extremely high. That's > 1000 mSV annual exposure at the wrist. You'd likely get a substantial total body dose from that as well...If that reading is true, I'd suggest getting rid of the watch.

    But I doubt that's an accurate reading.
     
  6. Leica May 9, 2019

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  7. Leica May 9, 2019

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    i dont know if it’s psychological but i do headache and arm soreness while wearing it . my friend has a 1960s red sub and i will go over and test it with my counter later.
     
  8. jshaw083 May 9, 2019

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    Are you able to confirm your readings with a different brand of radiation detector?
     
  9. 77deluxe May 9, 2019

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    Red 1680 sub will be tritium
     
  10. jshaw083 May 9, 2019

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    Commercial radiation detectors use a sodium iodide detector that only detects gamma or x-ray particles. It won't detect alpha radiation, and tritium emits 100% alpha emissions. Radium is ~96% alpha with 4% gamma. The gamma is what we worry about and that's what your probably measuring with your detector.
     
  11. AdInfinitum May 9, 2019

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    Steel (at a greater thickness than lead) will do the trick too! ;)
    upload_2019-5-9_15-3-30.jpeg
    From US Dep't Commerce Nat'l Bureau of Standards
     
  12. Leica May 9, 2019

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    l
    i put at 4cm stainless steel metal on top of it and it measure 2-2.3uSv/hr in 3mins testing.

    I will pay a visit to my watchmaker , he said he has radium watches
     
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  13. M'Bob May 9, 2019

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    Just to be clear, as far as you know: top- quality Geiger counters measure just gamma...or gamma and alpha? And, if a device only measures gamma, that's not an accuracy liability for measuring radium watches?
     
  14. Leica May 9, 2019

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    this is the device i measured with, I contacted(sent them a video) the manufacturer if the reading could be faulty they say it looks correct. Did reset , recalibrate, result was consistent.

    https://www.gqelectronicsllc.com/comersus/store/comersus_viewItem.asp?idProduct=5637
     
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  15. jshaw083 May 9, 2019

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    Most commerical detectors (e.g. Radex) only detect gamma. You need specialised devices to measure alpha, and usually the devices that measure alpha only measure alpha, not gamma and alpha. Reason being that we generally "don't care" about alpha radiation, given it only penetrates a few millimetres away from the source. The large alpha particles are block by air, the watch case, and skin. It is believed to largely be biologically harmless (as long as you don't ingest an alpha emitter).

    Generally if you have a radium watch, you only care about the gamma emissions. That's why tritium started being used in the 70s. Tritium emits 100% alpha, so it's considered much safer (and its half-life is 12 years, so this also contributes to the "safety").
     
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  16. M'Bob May 9, 2019

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    Thanks much for the reply.
     
  17. Leica May 9, 2019

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    not inhale , ingest or contact with wound

    but do they travel like dust?
     
    92CA1B5B-90A2-4CE2-A0EC-5121F7DAED23.jpeg
  18. Leica May 9, 2019

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  19. M'Bob May 10, 2019

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    If you open the back of a radium-lumed watch, where there is degradation of that material, there is certainly that possibility.
     
    Edited May 10, 2019
  20. Tony C. Ωf Jury member May 10, 2019

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    Yes, 84 microsieverts is exceptionally high. In my experience, the typical "high" registers are in the 20-30 range, and I have tested dozens of radium dial watches.

    I suppose that the sheer volume of lume on the Enicar was the main problem.