Jeff Liebermann Inscribed thus:

On Fri, 23 Apr 2010 16:00:06 +0100, "N_Cook"
wrote:

Now there is no thorium loaded gas mantles around these days

Ummm... check out the gas and kerosene mantles from China. Some are
hot:

http://www.tradevv.com/chinasuppliers/yansong_p_4e599/china-Gas-mantle.html
Incidentally, I once sacrificed one of my radioactive thorium Coleman
lantern mantles and ran a side by side comparison of the brightness
with a current non-radioactive zirconium mantle. The radioactive
mantle was MUCH brighter.

nor radium
dials , what is commonly around to give an above background check that
they are working ?

I like to use KCL (potassium salt, lite salt, or low-sodium salt). The
Potassium 40 is radioactive (450pCi/gram):
http://802.11junk.com/jeffl/crud/salt.jpg
http://www.angelfire.com/electronic/cwillis/rad/nosalt.html
It's not very hot but works well enough with a GM tube. Also lots of
fun going to the market with my 1950's GM counter. I once found some
brand of sea salt that was really hot, but it had been withdrawn or
recalled before I could return to buy some.

While at the market, try brazil nuts, acorns, and bananas. K-40 but
only when grown with massive overkill doses of fertilizer. Also try
cat litter. They all show up hot with my scintillation counter, but
are very weak with the GM tube.

If you go to the hardware store, check out the high phosphate
fertilizer. The stuff has uranium, K-40, thorium, radium, and who
know what else in it.

While at the hardware store, see if they have any tungsten stick arc
electrodes. They have some Thorium mixed in.

At home, if you have a dark colored granite counter top, you'll find
it somewhat radioactive from uranium.

http://greenbuildingelements.com/2009/03/27/granite-showrooms-continue-selling-radioactive-granite/
The problem isn't so much the radiation. It's the radon gas that it
produces.

Got any pottery or kitchen plates with a yellow or bright orange glaze
(Fiestaware)? If so, they're uranium oxide.

Got any old cameras or eyeglasses made between WWII and about 1980?
Most lenses have thorium mixed into the glass to increase the index of
refraction. These are really weak and will only show up on my
scintillation counter.

Got a heavy scotch tape dispenser with a sand-epoxy mix in the base?
The sand has thorium mixed in.

Got an old static eliminator for removing the static electricity from
old vinyl records? If so, it's quite hot with Polonium.

Mo
http://www.kronjaeger.com/hv-old/radio/src/index.html
http://www.anythingradioactive.com/radsamples.htm
http://www.physics.isu.edu/radinf/natural.htm See section on food.

Hey Jeff,
I've several old valves (Tubes) that are marked as containing "Radio
Active Material" with a "Do not Break Glass" and a yellow sticker on
them. CV number marking. Any ideas ?
They are stored in a box somewhere. If I can find them I'll come back
with the CV numbers.

--
Best Regards:
Baron.