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Re: Fire Alarms?

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  • Robert Atkinson
    Hi Keith, It s not all Americans here ;-) Am241 also has a weak gamma emission, very handy for checking thin crystal NaI(Tl) scintillators like the
    Message 1 of 14 , Mar 1, 2007
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      Hi Keith,
      It's not all Americans here ;-)
      Am241 also has a weak gamma emission, very handy for checking thin
      crystal NaI(Tl) scintillators like the Mini-Instruments 44A. These ae
      sometimes called LEG detectors and used to detect Pu and other low
      energy gamma emitters.

      Robert.

      --- In CDV700CLUB@yahoogroups.com, "Keith Watt RN" <webs@...> wrote:
      >
      > Hi, we had the local fire department round today and they replaced
      all
      > our old fire alarms, these are the type powered by a small 9 volt
      > battery.
      >
      > The alarms were some 15 years old and I decided to pull one of them
      to
      > pieces. The chamber that has the source was dismantled and a
      threaded
      > object about 1/8th inch by about 1/4 inch long was removed. This
      source
      > appears incredibly hot when put next to my counter on a pancake
      probe.
      > The counter reads over 100,000 CPM, but what ever the source is, it
      has
      > no penetrating ability, the count dropping to background levels
      with
      > just a piece of polyethylene or paper inserted between the source
      and
      > the pancake.
      >
      > The question is, what are these sources in the smoke alarms and if
      they
      > appear so hot, how dangerous are they - do I dispose of this source
      > carefully or is it really benign?
      >
      > Keith.
      >
    • Geo
      I can t comment too much on this but see no reason that I can t repeat some history. I used to make a brass holder for the pellets removed from smoke
      Message 2 of 14 , Mar 1, 2007
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        I can't comment too much on this but see no reason that I can't
        repeat some history.

        I used to make a brass holder for the pellets removed from smoke
        detectors, providing a large enough item that it wouldn't get lost
        and had a flat base for positioning for experiments. Also the pellet
        was covered by a very thin Mylar window so the particles and rays
        could get out but no possible dust could escape. It was beautiful,
        functional and safe. I called it the Safe Alpha Source.

        Problem is, it is illegal to dismantle smoke detectors in America
        WITHOUT A LICENSE, so I was busted by the NRC. Busted hard. This was
        some years ago but I still live under the threat of prosecution.

        They had no problem with my product, they told me they approved of
        it and thought it was cool, all I had to do was purchase a $6,000
        USD LICENSE per YEAR. For an item that cost me 8.00 and I was
        selling for 15.00, after an hours worth of lathe work. Not to
        mention eBay fees etc. It was a labor of love that could have turned
        into HARD LABOR for me, at no profit.

        Sometimes I seen like a nanny when I caution about safety or
        legality, this is the reason why.

        Have fun

        Geo

        --- In CDV700CLUB@yahoogroups.com, "Robert Atkinson"
        <robert8rpi@...> wrote:
        >
        > Hi Keith,
        > It's not all Americans here ;-)
        > Am241 also has a weak gamma emission, very handy for checking thin
        > crystal NaI(Tl) scintillators like the Mini-Instruments 44A. These
        ae
        > sometimes called LEG detectors and used to detect Pu and other low
        > energy gamma emitters.
        >
        > Robert.
        >
        > --- In CDV700CLUB@yahoogroups.com, "Keith Watt RN" <webs@> wrote:
        > >
        > > Hi, we had the local fire department round today and they
        replaced
        > all
        > > our old fire alarms, these are the type powered by a small 9
        volt
        > > battery.
        > >
        > > The alarms were some 15 years old and I decided to pull one of
        them
        > to
        > > pieces. The chamber that has the source was dismantled and a
        > threaded
        > > object about 1/8th inch by about 1/4 inch long was removed. This
        > source
        > > appears incredibly hot when put next to my counter on a pancake
        > probe.
        > > The counter reads over 100,000 CPM, but what ever the source is,
        it
        > has
        > > no penetrating ability, the count dropping to background levels
        > with
        > > just a piece of polyethylene or paper inserted between the
        source
        > and
        > > the pancake.
        > >
        > > The question is, what are these sources in the smoke alarms and
        if
        > they
        > > appear so hot, how dangerous are they - do I dispose of this
        source
        > > carefully or is it really benign?
        > >
        > > Keith.
        > >
        >
      • mdi48161
        I was wondering if the electronics could be used for other projects. Does anyone have information on the specs for the detection circuitery? Thank you Edward
        Message 3 of 14 , Mar 1, 2007
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          I was wondering if the electronics could be used for other projects.
          Does anyone have information on the specs for the detection circuitery?

          Thank you

          Edward
        • DH
          ... material ... They shouldn t have said gold. Now some yahoo will try recovering gold from them. Which will work, but..
          Message 4 of 14 , Mar 2, 2007
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            --- In CDV700CLUB@yahoogroups.com, lnmolino@... wrote:
            >> Ionization technology also includes a chamber containing radioactive
            material
            > incorporated into a gold matrix.

            They shouldn't have said gold. Now some yahoo will try
            recovering gold from them. Which will work, but..
          • DH
            ... circuitery? See http://www.eskimo.com/~eresrch/detecting_random.pdf for a good analysis. Its an open-chambered ionization meter.
            Message 5 of 14 , Mar 2, 2007
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              --- In CDV700CLUB@yahoogroups.com, "mdi48161" <mdi48161@...> wrote:
              >
              > I was wondering if the electronics could be used for other projects.
              > Does anyone have information on the specs for the detection
              circuitery?

              See http://www.eskimo.com/~eresrch/detecting_random.pdf
              for a good analysis. Its an open-chambered ionization
              meter.
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