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 Why are netc readings higher than 
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Joined: Fri Jan 31, 2014 5:28 pm
Posts: 42
This site is similar to netc:

Why are readings on some stations on netc so much higher? sets an alert when station counts are over 100, while on netc, many stations are green with averages counts in the hundreds. Is it a difference in the software? I'm just guessing, but perhaps one is reporting peak cpm, while another takes an average over several hours or days.

The reason I'm asking is people are starting to freak out after the May 22 Fukushima webcam footage showing a red glow that some say was a fire, and then finding this site which seams to confirm their worst fears. Most don't understand that natural radon can cause readings to go up and down, and that if the cause was man made isotopes like Cs, then an isotope analysis can distinguish between the two. A smoking gun as it were. No one is reporting upticks in Cs.

Wed May 28, 2014 7:18 am

Joined: Fri Jan 31, 2014 5:28 pm
Posts: 42
Thinking about it, the average readings on netc that are in the hundreds would totally make sense if the detectors were reporting results on the x0.1 scale.

Wed May 28, 2014 9:52 am
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Joined: Fri Nov 01, 2013 1:07 pm
Posts: 126
Location: St. Charles, IL
Green doesn't mean "good" and we should not compare what is going on here on this site elsewhere because this site should be thought of as an early warning / detection site. As I understand it, Green means the counts are within N.O.R.M. range over period of last 30 days. The icons/colors change - which represent degrees of overall increase - when the CPM exceed the N.O.R.M. over last 30 days period of history. So today, my station reads in the 20's and my location is currently set to green status. If tomorrow or even later today an unusual plume that is packed with bad stuff makes it my way, my counter will increase and set off an alarm condition. This is because the CPM is outside of N.O.R.M. which is maintained in NETC's database. The appropriate alarm condition that is triggered will correspond the degree of elevation which will be automatically applied based on NETC's algorithm and the color status/icon on the map will change accordingly. If the elevation remains constant over a period of time (I believe always taking last rolling 30 days of measurement into account), well eventually my icon will revert back from whatever elevated status was applied - to a Green status and my new N.O.R.M. may end being in the 50's or 60's or whatever number going forward. What matters here is that I am alerted to the fact a spike has occurred allowing me to take whatever precautionary measures I can take and monitor CPM ups/downs going forward.

Like has been said before, NETC will show many spots in Fuku as Green status. Obviously we all know Fuku is in bad shape, so how could status be set to Green? Well, hopefully this explanation satisfies that question....GREEN DOES NOT NECESSARILY EQUATE TO GOOD.

There is a comprehensive discussion thread on this very topic: This site publishes the EPA sites counts as a courtesy service but mainly consists of private monitoring stations (like myself and many others) who have their own equipment/configuration some which are collecting data inside private residences, others who have stations outdoors with HEPA filters similar to that of what the EPA uses. NETC private stations begin with a "1" for the ID. EPA sites begin with a "5" for station ID. EPA sites having been going up and down over last 6 months. What is good about us private station monitors is when EPA is offline whether due to legitimate malfunction or some bureaucrat decides to throw the switch to the off position, we still can be empowered with the tools/technology to self-maintain.

The moderators will surely jump in here to clarify further, but in a nutshell what other sites do/how they do what they do, etc. can't be directly applied here for these reasons and probably others I failed to mentioned. If I am wrong in any of my understanding, the experts will chime in. Just a user here so pardon if I made any mistakes in my response.

Hope this helps.


Wed May 28, 2014 1:58 pm

Joined: Thu Mar 06, 2014 1:25 pm
Posts: 182
am, afaik, this site's readings, posted from GM counters in the vicinity of daiichi, showed little, or no increase in rd levels, at that time... although they re, in fact, darned high!

Myself, I watch for changes... Today, there are 9 stations in usa that are at the radcon 4 level.
On a scale using netc alone, that is bad.

Good luck on that!

Wed May 28, 2014 2:19 pm

Joined: Fri Jan 31, 2014 5:28 pm
Posts: 42
Thanks EB789320, I do believe you helped answer my questions. After taking another look at the map, it appears that private sites with id's starting with 1 typically have double digit readings, like in the twenties, while EPA sites, with ids starting with 5, typically have reading in the hundreds.

This kind of makes sense, because the sensitivity of a detector affects the number of counts per minute, so EPA detectors must be about an order of magnitude more sensitive than what most consumers can afford. I also visited the EPA RadNet website showing the monitoring stations which was kind of interesting.

The youtube video that used the netc map and claimed that the Billings MT reading of 600 was proof we were getting fallout from a unit 4 fire, didn't mention that this number was actually really close to that stations 30 day average. It caught my attention because I used to live near there.

Thanks again!

Wed May 28, 2014 7:45 pm
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