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UnstableIsotope
USA
67 Posts |
 Posted - 12/06/2023 : 08:02:57
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I was playing around with the various "Fast Estimate Time" settings while in dual tube mode with individual tube counts displayed.
If the 60s or Dynamic options are used, CPM1 counts dynamically and CPM2 remains at zero for background levels.
If the 5,10,15, or 30s options are used, CPM2 remains a constant 1 that is added to the total.
This can't be normal operation.
I believe my second tube is working normally as CPM2 will register as high as 70 or so counts in the presence of a Uranium ore sample I have (5500 CPM measured with Ludlum pancake). |
Edited by - UnstableIsotope on 12/06/2023 11:04:41
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| Reply #1
EmfDev
2260 Posts |
Posted - 12/06/2023 : 14:04:05
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| Is it also the case as the latest update? |
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| Reply #2
UnstableIsotope
USA
67 Posts |
Posted - 12/06/2023 : 17:32:38
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| I'll let you know. |
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| Reply #3
UnstableIsotope
USA
67 Posts |
Posted - 12/06/2023 : 19:45:04
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Erroneous CPM2 behavior is still the same in 2.52.
I tested 5,10,15,20 and 30s. All those settings showed the CPM2:1 value.
60 and Dynamic settings still show CPM2:0 for background levels. |
Edited by - UnstableIsotope on 12/06/2023 19:45:47 |
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| Reply #4
ullix
Germany
1177 Posts |
Posted - 12/07/2023 : 00:43:03
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| What is the meaning of "CPM2:1"? |
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| Reply #5
UnstableIsotope
USA
67 Posts |
Posted - 12/07/2023 : 05:44:05
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If you turn on the individual tube count option, you'll see a CPM1:XXX CPM2:XXX shown on the "Large Font" screen. These are the individual counts for each tube. These will display (oddly) even if you are running either of the single tube modes. It only makes sense in dual tube mode.
Obviously, if there are no counts on a given tube, it should show zero. It appears that using anything other than 60 or Dynamic settings for the "Fast Estimate Time" options limits the minimum value of CPM2 to 1. It may also do the same to CPM1. |
Edited by - UnstableIsotope on 12/07/2023 14:38:28 |
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| Reply #6
ullix
Germany
1177 Posts |
Posted - 12/08/2023 : 01:59:26
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I already commented this elsewhere, but the problem here is very likely the same:
These spikes are very likely all a consequence of the inappropriate use of the "Fast estimate". It is a nuisance and should be switched off by setting it to 60 (sec)!
If you wish you can use GeigerLog to simulate the bad behavior of this setting. Don't use it!
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| Reply #7
UnstableIsotope
USA
67 Posts |
Posted - 12/08/2023 : 07:31:43
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| I generally don't use the short estimate windows. They are necessarily less accurate but they should still not show erroneous stuck 1 counts. I wonder if this is some floating point to integer conversion issue in the code that effects any of the short windows. |
Edited by - UnstableIsotope on 12/08/2023 11:56:52 |
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| Reply #8
EmfDev
2260 Posts |
Posted - 12/08/2023 : 11:29:59
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| The stuck 1 count is because 0 radiation is just not right but should not apply to tube 2 or should just show raw data. |
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| Reply #9
UnstableIsotope
USA
67 Posts |
Posted - 12/08/2023 : 11:58:23
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| If that's the case though, why don't the Dynamic or 60s options show the stuck 1? |
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Topic |
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BUG: 500+ Erroneous count "CPM2:1"
