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How hot is too hot? Geiger counter and radium.

  1. Spartcom5 Oct 19, 2020

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    Yes yes I know another radium thread. But I do have a genuine question. I have recently acquired a few watches and one in particular gives me concern. I have not owned a watch this hot yet. It makes my counter go crazy. It gives off a reading of 2300 CPM when placed against the crystal of the watch, when held about 8 inches it still goes above background levels, and it reads 100 CPM when placed against the case back. This to me still seems very high? Does anyone know if this is safe enough to wear at these levels? Most of my other radium watches are a fraction of this one, most being 500-800 CPM.


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  2. Tony C. Ωf Jury member Oct 19, 2020

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    14.37 is high, but I've seen higher. I wouldn't worry about wearing such a watch, but I would take it off before sleeping, and make sure that the crystal is fully intact.
     
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  3. BrianPankow Oct 19, 2020

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    If you’d like to see if any radioactive material is making it out of the case lightly wet a tissue with some alcohol and give the watch a wipe down. Take your wipe and counter to a low background area and see if you get any reading from the tissue above background. If nothing, you should be good. I would advise against taking the watch apart. Radium is a major concern in taken internally.
     
  4. JwRosenthal Oct 19, 2020

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    What is the watch?
     
  5. Vintagewtchzilla Oct 20, 2020

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    well that's in lower range of radium dials , my lowest watch has about 12 and the highest shoots beyond 30 millisivat but that is still a kindergarden when compared to a friends blancpains.

    don't worry too much and read the extensive threads about radium from start to end this will answer your questions
     
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  6. mzinski Oct 20, 2020

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    Wow! You must mean microsievert (μSv/h). 30 millisievert (mSv/h) is 30,000μSv/h - this is nearing the allowable dosage yearly by radiation workers.

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    I was just inspecting an old Movado with radium Arabic numerals the other week. My geiger counter shot up to 70μSv/h. If I were to have this on me continually, crystal facing my skin, I would be exposed to approximately 613mSv in a year (70μSv/h x 24hr x 365days). At 14μSv/h, you could hypothetically wear your watch ~3,600 hours in a year until you reach the maximum allowable exposure for radiation workers. So - take it off at night and don't eat it, you'll probably be okay.

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  7. Vintagewtchzilla Oct 20, 2020

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    lol yes micro ... not milli .... my bad.