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 Arkansas 
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Joined: Fri Aug 15, 2014 3:38 pm
Posts: 40
Why is the EPA site in Arkansas such a higher CPM than the NETC ones?


Thu Sep 18, 2014 4:14 pm
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Joined: Fri May 31, 2013 8:12 pm
Posts: 66
Different equipment...different sensitivity. Mostly, EPA uses scintillator detectors and netc stations use geiger counters.

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My Station Location : http://www.netc.com/map5.php?ll=-43.1618524,147.07710599999996 - Tasmania, Australia.


Mon Sep 22, 2014 1:16 am
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Joined: Thu Mar 06, 2014 1:25 pm
Posts: 182
IMO

I do not agree with the filter method of taking readings.

Hot particles will be trapped on the filter, then give a steadily rising particulate count of the aggregate, which is increasing, until the filter is changed.

Well, I guess that's kinda like a lung, which unfortunately can't be changed!

I think it might be better, to see what kinda hot particles are flying by, and being logged by the geiger tube as they pass...

In this manner of logging, you can watch for trends.

With a filter, you could see a rise in activity, then back to zero, and perhaps another rise, or maybe not... ???

My opinion... any thoughts on this?

Best
rc


Fri Sep 26, 2014 5:04 pm
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Joined: Mon Jan 28, 2013 6:51 pm
Posts: 739
Location: Arkansas
The idea of filters came from the EPA, they use filters on their outside unit too.


Fri Sep 26, 2014 10:13 pm
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Joined: Mon Jan 28, 2013 7:40 pm
Posts: 2803
Location: Illinois
Using the filter method also allows for the earliest detection. Using just the geiger counter, you will miss smaller patterns.

I gladly replace the filter whenever I suspect a trapped hot particle, just as I did today.

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MY OUTSIDE RADIATION MONITORING STATION:
South Beloit, Illinois - GMC200 Outside on HEPA air purifier, ground level, facing West.
http://netc.com/chart/view.php?n=1%3AEB5A139C


Sat Sep 27, 2014 5:34 am
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Joined: Thu Mar 06, 2014 1:25 pm
Posts: 182
Tnx guys!

IIRC, there was mention, (I think by Sternglass), that the monitoring agency, at that time, had low readings that were inconsistent, for some reason...

Upon consideration, and further investigation, it was discovered the practice was to have a flat sheet of sticky paper exposed to the sky, in hopes of catching whatever fallout occurred.
It seems, this was ineffective in areas where it was dry, and dusty. Especially when compared to areas of the country that were wet, and rainy.

I'm thinking, (can u see the wheels turning?), some sort of ducted venturi, with the GM tube incorporated within, might give a good depiction of what is flying by, without the distinct measurement of arrival of a hot particle causing the count to rise, and become lodged at that particular level.

Just trying to build a better mousetrap! lol

Golly!
Many thanks to netc and all who participate in providing us an option to what our well paid government agencies should be doing very well, on our behalf.

Best
rc


Sun Sep 28, 2014 2:54 pm
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Joined: Mon Jan 28, 2013 7:40 pm
Posts: 2803
Location: Illinois
Remember better detection without using a HEPA filter would require better/costly equipment. Since most are on a shoestring budget, the HEPA filter and $85 GMC-200 I use make a great choice.

_________________
MY OUTSIDE RADIATION MONITORING STATION:
South Beloit, Illinois - GMC200 Outside on HEPA air purifier, ground level, facing West.
http://netc.com/chart/view.php?n=1%3AEB5A139C


Sun Sep 28, 2014 4:48 pm
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