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ceandre27
9 Posts |
 Posted - 02/07/2018 : 06:46:22
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Hi ppl!
I just got my GMC-600, and I'm running some tests on them both sametime.
Then, I just noticed something weird on CPM / uSv/h.
On GMC-500+ (M4011 + SI-3BG tubes) I got:
uSv/h: 0.15
1427 CPM after 1 hour
On GMC-600 (SBT-11 pancake) I got:
uSv/h: 0.09
1755 CPM after 1 hour
I know, SBT-11 is more sensitive, but WHY I got lower uSv/h even with MORE CPM ??
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Edited by - ceandre27 on 02/07/2018 06:48:22
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| Reply #1
marzio
Italy
16 Posts |
Posted - 02/07/2018 : 11:30:37
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i hope that this image can help you.
GMC-600+ (LND7317)
your GMC-600 is wrapped in nylon
may it lose sensitivity compared to the GMC-500?
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Marcus |
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| Reply #2
ceandre27
9 Posts |
Posted - 02/07/2018 : 14:13:47
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Hi Marzio!
I open a hole on plastic film at sensor window :)
What I think weird it's ratio CPM x uSv/h, from one unit to another. 600 unit got MORE CPM than, but it's counting LESS on uSv/h unit.
Both turned on same time, side by side. I know which 600 must get more CPM because it's more sensitive, but what intrigues me is the lower uSv / h value
Carlos |
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| Reply #3
marzio
Italy
16 Posts |
Posted - 02/07/2018 : 14:41:22
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hi Carlos,
have you modify the 'calibrate' menu?
the relation among CPM and uS/h can be changed in base of the sensibility of the tube.
if you have changed the relation then try to execute a 'factory reset'.
ciao, marzio
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Marcus |
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| Reply #4
ceandre27
9 Posts |
Posted - 02/07/2018 : 18:53:21
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Hi Marcus,
No, I not changed anything on calibrate menu :|
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| Reply #5
ZLM
1261 Posts |
Posted - 02/07/2018 : 22:03:54
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| ceandre27, each tube has slight different conversion rate. In your case, you can adjust the conversion rate. Go to Init menu and then select Calibration 1, change 300 to 230. |
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Topic |
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GMC-500+ vs GMC-600
