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martinmo1
1 Posts |
 Posted - 09/26/2021 : 04:59:16
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Hi !
Just bought a new GMC 320 and to test it out, I did a 100 mins time count on my fire detector containing americanium. I'm obtaining the about the same count as background radiation. I'm wondering if that is normal. Looking at you tube, I know that some are actually extracting the americanium from the device to pick up it's radiotion with the GMC so that made me wonder if the reason why I don't detect anything is because my fire detector device is somehow shielded to minimize radiation exposure risk ? Otherwise, could my device be simply defective ?
Thanks ! |
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| Reply #1
ullix
Germany
1171 Posts |
Posted - 09/26/2021 : 23:36:32
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You probably meant Americium? If it is in your fire detector (are you sure it is there?) it likely is isotope 241.
You can read everywhere that this is a "pure" alpha emitter, and alphas cannot be detected in counters with glass Geiger tubes, such as a GMC-320.
However, as much as I know all, no exception, of those alpha emitters can emit gamma through some decay paths, at least through decay of daughter nuclei. Shown next is a gamma spectrum of Am241, and you see some very prominent lines below 150keV, but also some crumbs up to 500 keV.
The very low gammas might not be detectable in your counter, because they may not even pass the plastic of the counter housing. You might see some counts when you take off the back-plate and try again. But, I agree, something higher than background should be visible!
My recommendation is always to do some easy tests using household item containing Potassium. Read details in my "Potty Training" article: https://sourceforge.net/projects/geigerlog/files/Articles/
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| Reply #2
EmfDev
2250 Posts |
Posted - 09/27/2021 : 10:00:23
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Hi Martinmo1, you can watch the following video on how to disassemble the smoke detector to detect the radiation. Although we do not recommend doing it. But if you do, you do not need to remove the metal enclosure after removing the plastic cover.
https://www.youtube.com/watch?v=dvXtJx27ys4&ab_channel=GoProspecting |
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New GMC320 not detecting radiation fire detector
