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Global Radiation monitoring system

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radhoo

Wed Jul 17 2013, 12:07PM

Registered Member #1938 Joined: Sun Jan 25 2009, 12:44PM
Location: Romania
Posts: 701

Proud Mary wrote ...

It would be interesting to monitor activity in the Bega Canal.

With this? :)

Bega:
426879 4265313588106 1208919993 N

Proud Mary

Wed Jul 17 2013, 05:34PM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

I was thinking of the single-ended glass beta-gamma probe type (for example, Centronics B12H) to detect radioactivity in the water as it flows past.

Clearly, there will not be many places on a river or canal where the amateur scientist can set up a permanent or semi-permanent detector in the water, and the Bega where it flows through TimiÅŸoara does not look like one of them, unless you know someone!

Lovely pictures, Radu!

Proud Mary

Fri Jul 19 2013, 02:02PM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

J Environ Radioact. 2011 Jul;102(7):703-12.

Dynamics, deterministic nature and correlations of outdoor (222)Rn and (220)Rn progeny concentrations measured at BacÄƒu, Romania.

Cuculeanu V, Simion F, Simion E, Geicu A.
Faculty of Physics, University of Bucharest, Magurele, RO-077125 Bucharest, Romania.

Abstract
The long-term variation, nature and correlations of outdoor (222)Rn and (220)Rn progeny concentrations measured during the period 1994-2009 were investigated. The time series of data were obtained within the framework of the monitoring program performed by the Environmental Radioactivity Monitoring Station (ERMS) BacÄƒu, a component part of the National Environmental Radioactivity Survey Network (NERSN), coordinated by National Environmental Protection Agency (NEPA). The measuring method is based on the total beta measurements of atmospheric aerosol filters, using a low background total beta counter and ((90)Sr/Y) reference standard. Analysis of the time series of progeny concentrations in the low atmosphere makes evident different patterns of variation of these concentrations: diurnal, seasonal and annual. A possible relationship of progeny concentration increase with global warming is emphasized. In order to find the dominant frequency of the physical processes determining progeny concentration variability the power spectrum has been used. The deterministic nature of the time series of concentrations has been studied making use of the autocorrelation function and stationarity of the original data and of their phase randomized time series. Also, the correlations with meteorological parameters have been investigated using Pearson's correlation coefficient with corresponding level of significance.

radhoo

Tue Sept 03 2013, 01:26PM

Registered Member #1938 Joined: Sun Jan 25 2009, 12:44PM
Location: Romania
Posts: 701

Well, after all this time here are some updates.

I got in touch with Mr. Cuculeanu , and with a colleague of his , both extremely nice people and very helpful. We had the chance to discuss on some of the issues behind my device, their idea was that it will not be extremely accurate, but will work as an indicator of something going terribly wrong. Combined with global coverage should be quite useful.

I got the last modules, and will be putting everything together soon. Here are the Geiger tubes that will be used in the first set of devices:

radhoo

Sat Oct 05 2013, 07:51AM

Registered Member #1938 Joined: Sun Jan 25 2009, 12:44PM
Location: Romania
Posts: 701

I have decided to create three different uRADMonitor devices, that will be part of a single, global radiation surveillance network. From simpler to more complex these are:
- Model A: a small compact detector, this device contains a Geiger counter (SBM-20), a temperature sensor and a network interface. Encased in a small aluminum box, exposing only the DC power connector and the Ethernet port, intended as a fixed monitor. It's main advantage is the relative low production cost, while offering continuous radiation surveillance. The radiation detector is built upon a SBM-20 tube.
- Model B: the same compact size as the above, while also offering a LCD and a built in battery for remote operation. Model B can be used both as a monitor (when connected to the network via Ethernet cable) and as a mobile dosimeter showing the radiation levels on the LCD. Data is centralized only if the device is connected to the network (via the Ethernet cable).
- Model C: the most complex uRADMonitor design, features the same LCD as the previous model, but comes with more features and sensors: a GPS unit for mapping radiation data to location and also for standalone use as a GPS Tracker, a SDCard slot for logging the data when a network connection is not available, a wireless network connection to avoid installing complicated Ethernet cables - only DC power is required. Model C logs data to SDCard when Internet is not available and then uploads the data automatically when a connection becomes available. The wireless connection is via 2.4GHz radio waves to a local receiver connected to the Internet router by cable: so you can mount the uRADMonitor station outside, and have it upload data wirelessly to a receiver placed inside and connected via a short Ethernet cable to your Internet router. Very much like in this diagram:

I completed the PCB design for the uRADMonitor Model A, here a a few pics:

radhoo

Sat Oct 05 2013, 08:58AM

Registered Member #1938 Joined: Sun Jan 25 2009, 12:44PM
Location: Romania
Posts: 701

The Model A first prototype is ready. The board fits the case perfectly and it slides on the side rails when taking it in/out. The software is also close to the finish point and the device is already sending data to the uRADMonitor servers. I am happy with the size of the device, and the rugged feeling given by the robust aluminum case.

For this device I developed a tiny 400V inverter module, all with SMD components including the ferrite choke. No need to wind any other coils with hundreds of turns for ferrite core transformers like I did before. I'm sure this will be a huge time saver.
Simple and elegant, the board has plenty of space for adding all the extra features in Model B. Yes, the same case size will be used. Model B will also feature an LCD display.

The second picture shows the inverter module, just at the right of the Ethernet connector, on top of the red light background.
More details here:

Mads Barnkob

Sat Oct 05 2013, 04:07PM

Registered Member #1403 Joined: Tue Mar 18 2008, 06:05PM
Location: Denmark, Odense C
Posts: 1968

I am looking forward to install one of these outside my flat :)

radhoo

Sat Oct 05 2013, 05:15PM

Registered Member #1938 Joined: Sun Jan 25 2009, 12:44PM
Location: Romania
Posts: 701

Mads Barnkob wrote ...

I am looking forward to install one of these outside my flat :)

Thanks Mads, believe me or not, I am also very much looking forward to that - that is to finally have the entire system finished, checked and ready to go. And for my fellow 4HV'ers my goal is to provide the minimum price possible - covering only the Bill of MAterials.

A few more updates:

While designing the software for Model A, the inverter module required a few precise performance measurements to determine the best combination of duty cycle / frequency, so I put the data into a chart for easier understanding:

More details here:

radhoo

Tue Oct 08 2013, 08:38PM

Registered Member #1938 Joined: Sun Jan 25 2009, 12:44PM
Location: Romania
Posts: 701

As the last step was easy an involved only cutting the lid to make space for the two connectors, Ethernet and DC Power, I had some extra time for a photo session of the device. I also completed a second unit but with a slightly different aluminum case (BTW, I'd like to know which of the two cases you like better), so here are a few pics of the final uRADMonitor Model A, for the global radiation monitoring network (peanuts for size comparison only :) ):

The next few days I'll run tests for checking the quality, the stability and the behavior when exposed to various sources of radiation. Adjustments in software will be added where required.

Construction log is available here:

There is also a FB page some of you might be interested in (community support is much appreciated):

radhoo

Thu Oct 10 2013, 03:37PM

Registered Member #1938 Joined: Sun Jan 25 2009, 12:44PM
Location: Romania
Posts: 701

Here's a data feed from device #3 (the one in rectangular case):
Temperature:

Tube voltage:

CPM:

(*)uSV/h:

The dose in sieverts/h is an approximation. Some people seem to react exaggeratedly to this conversion, resulting in this note (like what other measurement is anything but yet another approximation).

Software not yet complete, so please excuse any issues/ errors you might find. More details in this post:

The units are currently indoors, and temperature sensor inside the casing, so temperature values are higher. The tube voltage has been set to 390V, I find this a convenient choice both in terms of inverter effort and SBM-20 tube's specs on the voltage interval.

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