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Meicool
1 Posts |
 Posted - 11/04/2023 : 18:20:33
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When I start the counter in a regular environment, it goes up to 240 CPM.????
please advise |
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| Reply #1
BlatantBarnacle
USA
7 Posts |
Posted - 11/05/2023 : 08:36:24
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| I'd be interested in a response to this as well. I'm getting spikes of 180-300 in a rural area. |
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| Reply #2
EmfDev
2157 Posts |
Posted - 11/06/2023 : 14:53:52
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| What units are those and does it only happen at startup? Or even after few minutes? Also please try to do a factory reset. |
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| Reply #3
BlatantBarnacle
USA
7 Posts |
Posted - 11/06/2023 : 16:14:41
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quote:
Originally posted by EmfDev
What units are those and does it only happen at startup? Or even after few minutes? Also please try to do a factory reset.
No, not during or at startup. Just random readings. I just got the meter yesterday.
I've gotten many spikes of 180-200-220-300cpm.
I saved my real time readings and downloaded my internal memory incase my readings are concerning. Ill take your advice and do a factory reset.
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| Reply #4
EmfDev
2157 Posts |
Posted - 11/06/2023 : 16:30:31
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| Yeah let me know if this happens anywhere without reason and if it still happens even after the factory reset. |
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| Reply #5
BlatantBarnacle
USA
7 Posts |
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| Reply #6
ullix
Germany
1115 Posts |
Posted - 11/21/2023 : 02:18:09
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@BlatantBarnacle: I took your data and analyzed them in GeigerLog. I show data from the 19th; those from the 18th are basically the same.
The time course is shown in the next picture, CPM in dark blue, CPS in magenta. Overlaid to the CPM is a yellow-framed curve, which is a Moving-Average over 1000 sec.
On first glance there is nothing wrong. The count rate is quite stable with an overall average of CPM=41.8. The min-max of CPM is 3 ... 79, also nothing extraordinary. The Moving-Average shows just the expected wiggle-pattern; there are no obvious deviations.
You never mentioned what counter you use, but assuming you measured background, then most likely you used a GMC-600?
Spikes as seen in this time course are normal for radioactivity. However, after having looked at myriads of such curves, some features do look a bit suspicious. The critical check is to apply the Poisson test.
GeigerLog can do this with the click of a button, and this is the outcome:
In one word: it looks awful!
Just so you can see how far this Poisson test is away from ok, here is the recent result from a GMC-300S counter, also measuring background; this one is like a text-book example:
If you don't know "Poisson", then you find further info in the GeigerLog manual (https://sourceforge.net/projects/geigerlog/), and in particular in my article "Potty Training" (https://sourceforge.net/projects/geigerlog/files/Articles/)
I have now seen many times that the GMC-600 counter is significantly distorting signals, and this seems to be the case here as well. It is not due to its pancake tube, as the same tube in other companies' counters behaves normally!
I could imagine that the very high spikes of CPM=300, which you mention, is due to this constructive defect on the GMC-600 counters.
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| Reply #7
EmfDev
2157 Posts |
Posted - 11/21/2023 : 14:39:22
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| Hi Blatant barnacle, what firmware version is installed on your device? |
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| Reply #8
BlatantBarnacle
USA
7 Posts |
Posted - 11/22/2023 : 10:50:44
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Thanks for the break down ullix. Do you mean it's not safe when you say it's awful? This stuff is way above my head, but I'm trying to learn.
EmfDev Rev 2.49.
2 days and 14 hours worth of readings in one csv. If anyone is curious.
https://drive.google.com/drive/folders/1wo5nM7uVuFBFbBw848RN9OtaoggX6QhK?usp=sharing
I will attempt wrapping my counter in lead mats with a clear memory and see what readings I get. |
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| Reply #9
EmfDev
2157 Posts |
Posted - 11/22/2023 : 12:45:32
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| Hi BlatantBarnacle, we have a newer update. Please email me or support with your serial number and I can generate the update for you. |
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| Reply #10
ullix
Germany
1115 Posts |
Posted - 11/23/2023 : 00:27:49
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quote:
Do you mean it's not safe when you say it's awful?
What do you mean: "safe" in which respect?
All evidence points to a design deficiency of the GMC-600 counter. What you observed are way-off readings which may be a direct consequence of this flaw. You can't hurt yourself by using this counter, but whether the counter delivers what you expect may be questionable.
Neither you nor Meicool have stated which counter you are using? Please, state; including firmware version!
P.S. the best format for sharing is the "bin" file. The CSV is in a really bad format, and takes too much effort to interpret. GeigerLog can read the bin file without problems.
P.S. For starters I recommend by "Potty Training" article https://sourceforge.net/projects/geigerlog/files/Articles/
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| Reply #11
BlatantBarnacle
USA
7 Posts |
Posted - 11/23/2023 : 08:58:38
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This is a GMC-600+ rev 2.49.
My apologies, I thought you were saying that the amount of radiation I may be receiving is awful or it could be a possibly defect.
I'll get the update from EmfDev and hopefully get some good readings. |
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| Reply #12
BlatantBarnacle
USA
7 Posts |
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| Reply #13
ullix
Germany
1115 Posts |
Posted - 11/29/2023 : 01:06:12
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@BlaantBarnacle:
Time course, Average, and Max are completely ok.
However, the Poisson check reveals that the data are bad!
This confirms again that the GMC-600 has a major design fault! I had demonstrated in the past that such deviations can result from too much capacitance in the anode voltage circuitry. This is a defect caused by wrong engineering, and cannot be fixed by software, aka firmware.
Use a different counter; you will never be able to judge the validity of data created with this counter!
You can test it yourself: install GeigerLog (https://sourceforge.net/projects/geigerlog/), activate "GMC counter", download the history, and push the "Poiss" button.
EDIT
I forgot: I noticed that during the first about 6 hours the count rate slowly crept up. Was there a reason for it, like you moved the counter to a different location? If not, it also is not a good sign, like a Warm-Up effect? |
Edited by - ullix on 11/29/2023 01:30:41 |
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| Reply #14
ihab17
Italy
213 Posts |
Posted - 11/29/2023 : 06:13:34
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quote:
Originally posted by ullix
However, the Poisson check reveals that the data are bad!
This confirms again that the GMC-600 has a major design fault!
Same as my case, so mine is not a defective unit-bad luck, rather than a defective product by design |
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| Reply #15
BlatantBarnacle
USA
7 Posts |
Posted - 11/29/2023 : 07:57:59
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| Thanks for checking the data again ullix. No, I hadn't moved it. I have it hanging on the wall a foot to my right. |
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Readings are to High
