| T O P I C    R E V I E W | 
              
              
                | ceandre27 | 
                Posted - 02/07/2018 : 06:46:22  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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                | 5   L A T E S T    R E P L I E S    (Newest First) | 
              
              
                | ZLM | 
                Posted - 02/07/2018 : 22:03:54  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.  | 
              
              
                | ceandre27 | 
                Posted - 02/07/2018 : 18:53:21  Hi Marcus,
  No, I not changed anything on calibrate menu :|
 
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                | marzio | 
                Posted - 02/07/2018 : 14:41:22  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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                | ceandre27 | 
                Posted - 02/07/2018 : 14:13:47  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 | 
              
              
                | marzio | 
                Posted - 02/07/2018 : 11:30:37  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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