Thermometer with separated mercury

Discussion in 'Darkroom Equipment' started by pbromaghin, Jun 15, 2012.

  1. pbromaghin

    pbromaghin Subscriber

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    I came across a really nice Kodak mercury thermometer mounted in a stainless steel protective bracket, but there is a little bit of mercury separated from the main body. How does one go about getting it to join back up?
     
  2. Bill Burk

    Bill Burk Subscriber

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    I've done this with many thermometers but you must be careful because it can break leaving you with a mercury clean-up...

    If spinning it like a psychrometer doesn't work, heat slowly until mercury reaches the top. Now I don't know if the Kodak thermometer has any tiny space at the top for air. If so you may be able to get some bubbles past the mercury and then cool down again. If not then it is dangerous to continue and someone else may have a better idea.

    ps. I work for Kodak but the opinions and positions I take are not necessarily those of EKC
     
  3. George Nova Scotia

    George Nova Scotia Subscriber

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    I've usually been able to shake any bubbles out of mercury thermometers. I had a quick look at the Type 3 I have and there doesn't seem to be much space at the top - if you do try heating I'd be very very careful and go slow. If you hear a snap call your local Hazmat team:sad:
     
  4. KenS

    KenS Member

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    Place the thermometer either in the freezer in an upright position for a few hours or upright on a container with a mixture of crushed ice and salt for as long as it takes for the mercury to recede into the bulb.
    Failing that.. and as a last resort..... holding the thermometer in an upright position, GENTLY tap in up and down onto a wooden table top. The height of half an an inch or so is more then enough. It may take about 15 minutes or more of GENTLE 'tapping'.
    Over many years I have had to perform such a 'rescue' about half a dozen times.

    Ken
     
  5. Bill Burk

    Bill Burk Subscriber

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    Cold and gentle tapping sounds better than heat (which works well for alcohol tank and tray thermometer)
     
  6. E76

    E76 Subscriber

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    I fixed separated mercury in a Kodak thermometer just the other day!

    Try tapping the thermometer on a desk first and see if you can't get most of it back together. If that doesn't work, you can carefully heat the thermometer over the stove until the mercury recombines. Be very careful not to fill the expansion chamber at the top more than two-thirds full or you risk cracking the thermometer.

    I used a combination of both techniques to recombine mine. I do not recommend spinning nor swinging the thermometer as someone else mentioned, as the thermometer could go flying across the room, shattering and spreading toxic mercury everywhere!
     
    Last edited by a moderator: Jun 16, 2012
  7. pbromaghin

    pbromaghin Subscriber

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    I've been spinning and tapping now and then. Thanks to all of you!

    Gawd, I love apug.
     
  8. cjbecker

    cjbecker Member

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    Its not that bad for you.
     
  9. George Nova Scotia

    George Nova Scotia Subscriber

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    Kodak Process Type 3 pdf

    Just for the record:
     

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  10. Bill Burk

    Bill Burk Subscriber

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    Awesome! We were all giving good advice!
     
  11. RalphLambrecht

    RalphLambrecht Subscriber

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    i heard tapping on a towel or a foam padded mouse ad works well!
    that's how my dad, a trained chemist and lab technician did it.
     
  12. pbromaghin

    pbromaghin Subscriber

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    Hey, its fixed!

    I followed those instructions from Kodak, heated it up into the expansion chamber and tapped it on a towel. There was a second separation, very tiny, and I had to get the mercury up into the expansion chamber 4=5 times before it all went back together.

    Many thanks for the great advice from all of you.

    Peter