Note: You must be registered in order to post a reply. To register, click here. Registration is FREE!
T O P I C R E V I E W
Posted - 02/24/2022 : 00:02:36 Hi there. A basic question? I know the human body is lightly radioactive. So is it possible that the cpm is a little bit higher if you hold the device in your hands instead of laying it on a table (per example). I donít know if this is a stupid question. But whatís your experiences? Thanks in advance. Best regards, Dirk
3 L A T E S T R E P L I E S (Newest First)
Posted - 03/03/2022 : 06:13:51 Hi. Thanks for your explanations and replies. Greetings, Dirk
Posted - 02/26/2022 : 01:23:30 In principle the idea is correct that the human body should put a few extra counts into a Geiger counter. However ...
The main source for the extra counts of radiation is Potassium (chemical sign: K), due to its content of the radioactive isotope K-40. Bananas actually contain roughly 50% more K-40 than the human body (3.6 vs. 2.5 g/kg). This resulted in the (in)famous definition of the "Banana equivalent dose". https://en.wikipedia.org/wiki/Banana_equivalent_dose
It takes some long measurement hours, and some digging into statistics to understand "Standard Deviation" and "Standard Error" before one is able to confirm success!
As the human body has lower K-40 content than a banana, longer times will be needed. Given that the statistic improves only with the square root of the counts, my guess is that at least (!) a week-long experiment, with constant recording, and changing every 20 hours from background to hand-holding will give enough data for a firm conclusion.
If you are not prepared for those long counter-sitting periods, maybe you can put the bar a bit lower: cocoa powder, as you can buy it from the supermarket, has even 4 times higher potassium than bananas (15.2 g/kg). My counter gave this result for switching between background and intimate contact between counter and cocoa powder:
But note the time scale: be patient when the count rate is low! And always verify proper Poisson statistics for your work to be valid, see article.
Posted - 02/25/2022 : 10:10:08 Hi Dirk, probably not. The geiger counter might not be sensitive enough to see the difference.