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Bobakman
USA
97 Posts |
Posted - 03/27/2023 : 19:33:12
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What is the GMC600+ maximum data recording time for each sample interval? I found only this in the manual: "NOTE: The history data memory will be used as a ring buffer. Once the end of the memory is reached, the oldest data will be over written. Carefully select the data saving interval to save memory space." I can't "carefully select the proper data saving interval" if I do not know the memory limitation as it relates to the time interval. I am thinking of recording the radiation data of a 12+hour flight and would like to know what the maximum recording time is prior to data being overwritten in the "ring buffer"? I would like to know the maximum recording time for one second and one minute sample intervals. Bob |
“If you want to find the secrets of the universe, think in terms of energy, frequency and vibration.” Nikola Tesla |
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Reply #1
ullix
Germany
1171 Posts |
Posted - 03/27/2023 : 23:48:48
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It depends!
Due to the storage algorithm of the GMC counters, no firm prediction can be made. More on this complicated mess in the GeigerLog Manual chapter "Appendix E – GMC Device: Internal Memory, Storage Format and Parsing Strategy".
But by experience the GMC-600 counter will last for a full day in CPS saving mode. But then you should do a History read-out. You don't need to hurry; do it once you have settled in the hotel room.
During the flight days you want the CPS mode in order to also catch the Xray checks. The CPM mode will last for even an extended vacation.
I suggest to erase the memory before you start.
To you and anyone else: I am very interested in all flight data; please post at the GeigerLog discussion site. https://sourceforge.net/p/geigerlog/discussion/
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Reply #2
ihab17
Italy
218 Posts |
Posted - 03/28/2023 : 05:42:24
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quote: Originally posted by Bobakman
What is the GMC600+ maximum data recording time for each sample interval? I found only this in the manual: "NOTE: The history data memory will be used as a ring buffer. Once the end of the memory is reached, the oldest data will be over written. Carefully select the data saving interval to save memory space." I can't "carefully select the proper data saving interval" if I do not know the memory limitation as it relates to the time interval. I am thinking of recording the radiation data of a 12+hour flight and would like to know what the maximum recording time is prior to data being overwritten in the "ring buffer"? I would like to know the maximum recording time for one second and one minute sample intervals. Bob
I don't think you'd run out of memory as I have been testing the device lately with a radioactive Iodine 131 contaminated cloth, with CPS=7000 for more than 12 hours, saving data every second, and the device didn't have any memory issue and didn't fill it. Also the battery seems to be fine (almost fully charged) even if my display never turns off, and I left it for more than 12 hours. |
Edited by - ihab17 on 03/28/2023 05:43:43 |
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Reply #3
Bobakman
USA
97 Posts |
Posted - 03/28/2023 : 15:07:59
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Thanks. I plan on starting the data acquisition on the tarmac at departure and ending it upon arrival at the gate. So looks like I should be OK baring any aircraft pressurization issues or events. If I do end up successfully preforming this Ullix I will definitely post the data at Sourceforge. Bob |
“If you want to find the secrets of the universe, think in terms of energy, frequency and vibration.” Nikola Tesla |
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Reply #4
ullix
Germany
1171 Posts |
Posted - 03/28/2023 : 23:53:27
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Bob, go for it at a leisurely pace, you'll have enough memory capacity in the counter. The benefit of starting the counter at home and stopping in the hotel is that you also get the background at both locations.
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Reply #5
Bobakman
USA
97 Posts |
Posted - 03/29/2023 : 06:51:10
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quote: Originally posted by ullix
Bob, go for it at a leisurely pace, you'll have enough memory capacity in the counter. The benefit of starting the counter at home and stopping in the hotel is that you also get the background at both locations.
Thanks Ullix this is a good point and one less thing to do while shuffling at the airport. I am now retired so I should take " leisurely" to heart LOL! Bob |
“If you want to find the secrets of the universe, think in terms of energy, frequency and vibration.” Nikola Tesla |
Edited by - Bobakman on 03/29/2023 18:50:46 |
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Reply #6
Bobakman
USA
97 Posts |
Posted - 03/29/2023 : 09:16:26
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One other question. Do you have a list of recommended settings I should make or verify in my 600+? Currently I have Fast Estimate time set to 60 Seconds and the tube dead time is enabled at 40Micro Seconds per the LND 7317 Spec sheet. I just want to ensure that the data is not skewed in anyway due to my 600+ settings. Bob |
“If you want to find the secrets of the universe, think in terms of energy, frequency and vibration.” Nikola Tesla |
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Reply #7
ullix
Germany
1171 Posts |
Posted - 03/30/2023 : 00:04:16
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quote: I just want to ensure that the data is not skewed in anyway due to my 600+ settings.
Good point. FET=60 (to switch it off) and tube deadtime DISABLED.
If the firmware does not allow to disable then set it to the shortest time available. Given the count rates you have to expect, it should not matter anyway. But the firmware has so many problems, I don't trust it. |
Edited by - ullix on 03/30/2023 07:48:41 |
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Reply #8
Bobakman
USA
97 Posts |
Posted - 03/30/2023 : 14:07:38
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quote: Originally posted by ullix
quote: I just want to ensure that the data is not skewed in anyway due to my 600+ settings.
Good point. FET=60 (to switch it off) and tube deadtime DISABLED.
If the firmware does not allow to disable then set it to the shortest time available. Given the count rates you have to expect, it should not matter anyway. But the firmware has so many problems, I don't trust it.
Great Thanks! Bob |
“If you want to find the secrets of the universe, think in terms of energy, frequency and vibration.” Nikola Tesla |
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