First idea, there are atmospheric tides (two per day) where the barometric pressure is high (i.e. there's extra pounds per square inch of atmosphere between ground and cosmic ray incident flux). So, two dips in a daily cycle is kinda... expected.
And, if solar wind activates upper-atmosphere atoms (adds neutrons, makes 'em slightly radioactive) there might also be a diurnal (once per day) component when those atoms mix with lower atmosphere. With enough phase shift due to mixing time, that can account for the nighttime high.
I would be tempted to bin the data about every hour, rather than every minute. That might remove enough of the noise that you could see something useful. Then compare successive 30-or-so day runs, to see if the daily variation remains.
Looks like fun.
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On a sunny day (Thu, 11 Jun 2015 11:53:52 -0700) it happened snipped-for-privacy@coop.radagast.org (Dave Platt) wrote in :
That is acces refused (think they want money). Anyway I think you could well be right. It also explains why the ramp position is different in winter, and constant at night in winter, as then the thermostat takes over and sets a minimum in that room.
I build a second counter that logs to SDcard, with geo position, so I may run that a while:
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Or maybe use the gamma spectrometer, no website yet, but :
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That one uses a Russian FEU-35 PMT and a plastic crystal from ebay.
But PMTs are sensitive to just about everything...
Maybe the simplest thing is to put the original GM tube it in an oven for a while... have to think about that, just the tube maybe... Small wooden box with heater.... insulated.
I'm a bit confused. I thought he said the experiment ran 24/7 and the graph was data over a year period, "one_year_ticks_minutes_zero_is_midnight.gif". But later he says it is for 100 days. Not that this matters a lot. Then there is a second graph of another data set which shows a rather different shape, "2013_feb2014_GM_tics.png". Even when the first data set is split into two halves the two curves don't look very similar to me.
Rather than sum the two data sets, I would like to see a correlation on them. I think this is simply a rather noisy data set and the "features" don't stand out very much from the noise, at least not in a repeatable way. Kinda like listening to sounds in the forest. Listen long enough and you hear what you want to hear. If the shapes of the data sets don't repeat, they are just some noise.
It was about strange things with the Geiger-Muller detector.... I couldn't see any design related things in the thread, nor do I know Jan Panteltje. My question was just informationally. No reason for blows below the belt.
I couldn't know that his circuit is well known in sed and anyone but me is knowing about his design, etc. ;-)
Low pass filtering his existing data will be more effective. NB he needs to use the solar day for binning correctly not the mean sun.
It would be easier to comprehend if the time axis was calibrated in hours rather than sample ticks. Then it would be obvious if certain features coincided with CH timings and going out to work etc.
That's why your teacher told you to listen before you speak. Better to keep your mouth shut and be thought an idiot than to open it and remove all doubt.
To know if the signals are unusual, you need to have an idea of what is the natural distribution of the variable. For example when counting photons, the data is Poisson distributed and variance = mean. Maybe your data follows a similar distribution, which would explain such low-frequency signal excursions as expected random variations. One way to test this idea would be to plot different combinations of measurements and see if the signal excursions persist. Another interesting plot would be a histogram to see if the data follows a recognizable distribution such as Gaussian, Poisson, etc..
On a sunny day (Fri, 12 Jun 2015 10:49:36 -0500) it happened ChesterW wrote in :
Yes, how's you string theory? I did not win the Euro Jackpot last night, so I am also looking if somebody took all past winning numbers and made a polynomial that sort of gets close to the next one Friday.
To be more specific, I think it makes a lot more sense to look for more down to earth booboos in the design / measurement setup at this point, like temperature and light effects on the GM tube, temperature effects on the electronics, power supply? Software peculiarities, is interrupt priority correct? GM ticks versus internal clock, etc etc (need to explain that peculiar second effect), usage errors: I stop logging some sometimes, ask for status, and even at one point changed GM tube voltage. Since we are talking many percents of deviation from a flat line it is 99.9999 percent certain that the problem is in the setup, not our understanding of the universe. :-)
The thing was just meant as a radiation alarm, not a scientific experiment. But it should be flat within reason. Had it been intended as experiment to detect some effect I would have set it up very differently, see tri_pic
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There you can have a go with all that math, you are most welcome to do that! Data is at bottom page for the last 3 years or so.
just for the giggles ;). This is the data of a given day:
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And this are the counts added up with three or four months worth of data: select time::time as time, sum(cpm) as cpm from radiation group by time::time order by time::time. I think, that's what you have done. The resulting graph:
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I have temperature data at my hands, but only from the outside, not the room where the GM tube is located. Maybe I should plot them side by side.
Regards hmw
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On a sunny day (Wed, 17 Jun 2015 20:54:25 +0200) it happened Michael Welle wrote in :
Very very interesting, Although less distinct, I see a similar ramp around 1000, There are also the peaks earlier, although those get less distinct with more data collected. At at the start of the last picture you can see it is more flat from 0 to 400.
Could well be temperature, do you have a thermostat running at night to keep temperature constant?
I haven't played around much with the data yet. I will do that if I have some spare time at my hands, or if there is a special request.
No, the temperature follows the outside temperature. The only 'thermostat' is the heat capacity of the walls of the building. Here is the temperature curve of that day:
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Regards hmw
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