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Sharynf1952
USA
2 Posts |
 Posted - 11/30/2019 : 22:04:35
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Hello. I was wondering if there is a setting to see if it's detecting, Gamma, Beta, or X -ray radiation. Or, am I supposed to know the range, and be able to self-categorize? (I see these types are listed in the User guide); in particular interested in Gamma. Just had radioactive Iodine treatment for thyroid cancer and those around me in the house think I'm a walking Chernobyl. Even though doctors have said it's OK after 3 to 7 days. I also read half-life of I-131 is 8 days, so that would be 40 days till 'back to normal'. Am trying to take readings to confirm. Got the tech's reading of me from four feet. It's a little hard to get back to the counter from 4 feet to take a reading, so will probably start at one foot and take a reading once a day for the next 30 days. Again, I still am not sure if I need the CPM's or the mRems... ??? |
S. Fernandez |
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| Reply #1
Sharynf1952
USA
2 Posts |
Posted - 11/30/2019 : 22:36:09
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All Forums
GQ Electronics Forums
2.GQ Geiger Muller Counter
Is my wall radioactive?
This link referred me to "User" Illex? and Sourceforce website ; and thank you; so it's reading both...
Interesting to see that readings on the device are room temperature dependent.
S. Fernandez
Concord, California US |
S. Fernandez |
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| Reply #2
ullix
Germany
1171 Posts |
Posted - 12/01/2019 : 05:26:12
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Hello Sharyn, first let's send you our well-wishes for a successful treatment! Despite the seriousness of this treatment, it surely cannot do any harm being curious about what is going on in oneself; and you do seem to be of the same opinion.
First, a Geiger counter, by its physical design, cannot distinguish between the radioactive events. Therefore, there cannot be a setting of any kind to distinguish between them, neither in the GQ counters, nor on any other device on earth working on the Geiger principle.
Gamma and X-ray is physically the same. The names are typically used to distinguish between the energies of those electromagnetic waves: X-ray is used for low energy, and Gamma for high energy radiation, but there is no border defined by any physical principle, and so there is a wide grey zone where either word is used. Typically X-ray is associated with man-made radiation in a doctor's office, and gamma with natural or technical things (minerals, nuclear power station, ...). Things get more murky when you deal with astronomy.
But Geiger counter also cannot distinguish between high and low energy - a count is a count. (Though Geiger counters do have a different sensitivity for different energies, but this is a another matter).
Iodine 131 is a pure beta radiator, but it decays to an excited state (a state of high energy) of its daughter nuclei Xe-131, and this atom looses its extra energy by pure gamma radiation. While I-131 has a half-live of ~8days, the half life of the excited state of Xe-131 is very short. Xe-131, after it lost the excitation, is a stable atom.
So, in principle you could detect both beta and gamma on yourself. However, beta radiation has a limited range, i.e. it is absorbed quickly by any material, even air. In tissue, the range is perhaps 1-2mm only! As I131 is injected into your body, the beta radiation might not even be able to cross your skin, let alone coming from the thyroid to the outside! Even a detector able to discriminate between beta and gamma (which a Geiger counter is not), is unlikely to even see any betas outside of your body.
More on this topic in Wikipedia, and in my "Potty Training ..." article on Geiger counter and some basic physics of radiation https://sourceforge.net/projects/geigerlog/files/Articles/
For the practical problem of measuring your body's radiation, I suggest to use my program GeigerLog, which allows live recording and visualizing in graphical form. You could connect the counter with a USB cable - a length of 4 feet is standard and even 8 feet should work -- and sit at the desktop or laptop computer and watch the screen. You could add comments to the recording (like distance, head, chest, feet,...) so you can later replay and reanalyze the data. The program is open source and available here: https://sourceforge.net/projects/geigerlog/
Be careful on interpreting the data: should the data suddenly drop from a high count rate to a very low count rate, it might be because the counter cannot keep up! There is a very long thread here in the forum on this topic. Should you experience anything like this, just keep the counter further away from your body; perhaps much further away, like 8 feet instead of 4!
All the best!
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| Reply #3
EmfDev
2250 Posts |
Posted - 12/02/2019 : 11:17:43
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| Hi Sharyn, we hope everything goes well with your treatment!. Thank you ullix for the very wonderful information as I also learned a lot from you. |
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newbie to GMC-300E+
