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[Phys-L] Re: Survey Meters



Interesting thought, that there is an equilibrium level of radon and
decay products in the room, and pasted on a TV screen.
What John called an initially stable level - though stability of a
decaying species sounds paradoxical.

I suppose the measured count rate from a wipe should be proportional
to the screen area. But then, the Buda initial count at 300 cpm
would be from a big, big screen TV compared to my test wipes
starting at 100 cpm?

Though I calibrated my survey meter, there's still the issue of
relative detector sensitivity/efficiency of course.

Brian
p.s. Apologies for reading my mail in reverse time order - a
function of Eudora.

At 11:22 AM 10/19/2005, Mike Edmiston, you wrote:
This means the data represent either the gammas or the betas (usually
gammas) from 214-Pb and 214-Bi, which, as I mentioned, are typically
what one examines when trying to detect radon.

Radon does indeed have a half-life of 3.8 days. If it's present at a
steady rate in the room, and assuming the CRT display is always on, then
an equilibrium ratio of radon daughters exists on the screen.
//
Michael D. Edmiston, Ph.D.
Professor of Chemistry and Physics
Bluffton University
Bluffton, OH 45817
(419)-358-3270
edmiston@bluffton.edu


The half life of radon is 3.8 days, and this half life
is about 40 minutes.....
Is this the radium a, b ,c, c', d route?


Brian Whatcott Altus OK Eureka!


Brian Whatcott Altus OK Eureka!