| T O P I C R E V I E W |
| mobiusloop |
Posted - 09/24/2012 : 13:58:11
As the maximum cpm currently possible is 65,535 and the conversion factor coded into the GMC-300 for the m4011 tube appears to be 300, the maximum level of radiation reportable before overflow is about 218 uSv/hr. Although I would never want to be in a situation where the meter read that high, the 218 uSv/hr limitation appears to be below the 1,000 uSv/hr of other manufacturers.
Perhaps my calculations are incorrect. |
| 4 L A T E S T R E P L I E S (Newest First) |
| mobiusloop |
Posted - 09/25/2012 : 05:19:29
Thank you. |
| ZLM |
Posted - 09/24/2012 : 20:26:18
For GMC-300, the maximum CPM is 65,535. User has no way to change it.
There is one way to extend high range detection: change to a low sensitivity tube and then recalibrate the reading.
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| mobiusloop |
Posted - 09/24/2012 : 16:27:53
If you are referring to changing the cpm to uSv/hr ratio using the calibration utility, this will not appropriately address the 218 uSv/hr limitation. For example, if I were to change one of the ratios to 100 cpm = .666 uSv the maximum uSv/hr would be approximately doubled to 437 uSv/hr but this would be 100% too high and be very inaccurate. Raising the uSv/hr using the calibration routine does not appear to address the maximum CPM limitation of 65,535.
If you mean the maximum CPM can be increased, the calibration utility does not seem to provide for this. Is there a user accessible utility that can be used?
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| ZLM |
Posted - 09/24/2012 : 16:07:25
The GMC-300 can be re-calibrated to different range.
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