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BlueSky
25 Posts |
 Posted - 01/24/2012 : 07:59:26
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I may be reading this wrong..is my uSv/h the same as in theis article of uSv/h?
Japan spike from 1/24 show .099 uSv/h, My coatpocket was .15 uSv/h microseiverts, and my basement showed 30 CPM .09 uSv/h. Isn’t that the same level as the Japan spike shown? Should I be alarmed with .09 reading? Not sure what the rest said on my meter (if it was .099 or not, but was definitely .09)
enenews.com/radiation-spikes-thoughout-tokyo-area-after-yesterdays-quake-charts
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Edited by - BlueSky on 01/24/2012 09:18:14
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Odiez1
73 Posts |
Posted - 01/24/2012 : 09:54:14
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Where are you? In Japan? If your basement was 30CPM, that's WELL within a 'normal' range. I have troubles accepting the conversion of CPM to uSv/h considering the equipment being used here. The Sievert unit of measure must be calibrated against a source which has an exactly known amount of emitted radioactivity, AND a detector (scintillator/ GM tube) with a exactly know efficiency.
en.wikipedia.org/wiki/Sievert
Can we say that the GMC-300 is perfectly calibrated against an NIST registered source (usually Cs137), and that the M4011 tube's effeciency for that kind of Gamma?
Then you open the real can of worms, because once calibrated, YOU CAN'T SAY SOMETHING IS .0xxx uSv/hr UNLESS YOU KNOW IT IS Cs137. Any other isotope (Sr90, Am241, Co60 etc..) will emit different Gammas and not be converted properly to Sieverts.
Sorry.. I wouldn't worry about any CPM under 40, personally. Don't EAT/Drink anything that would read over 40, don't be in a room with CPM over 60 for very long.
Go watch Antiprotons on youtube. ;-) |
-Odie |
Edited by - Odiez1 on 01/24/2012 09:59:19 |
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Odiez1
73 Posts |
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ZLM
1261 Posts |
Posted - 01/24/2012 : 10:46:58
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I agree with Odiez1.
The CPM should be used as reference since uSv/h has many factors affect its conversion accuracy.
The normal range CPM on GMC-300 is 15~40. Mostly it is in a 15~25 CPM range. If your get a consistant CPM reading over 60, then the background radiation is higher than normal. But that does not mean dangerous, but it is good to know where has higher radiation than normal
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| Reply #4
BlueSky
25 Posts |
Posted - 01/24/2012 : 11:23:25
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| Thanks guys, Im in Eastern PA, I'm really starting to figure this all out... |
Edited by - BlueSky on 01/24/2012 11:25:39 |
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Are my uSv/h readings looking correct ?
