I have a radioactivity counter going for a piece of Cs 137. You find it's log here http://a.djk.se/counts.txt
First column is the sequence number. Second column is the timestamp in seconds since 1970 with microsecond precision. I am trying to keep it at 2 seconds. When the ntp correction is done there can be a big timestep like this 33057 : 1324332734.041153 : 6850633 33058 : 1324332818.342256 : 6850938 Third column is the ticks in the geiger tube. Typically 200 per second. Sometimes the rechargeable battery runs out in the counter and then the counts drop. Sometimes data is missing but counts have to be accumulated over several minutes anyway to get statistical precision so this is not a problem. The counter is 32 bit unsigned and will return to zero after 4 billion something. This is close to 8 months. This is a setup trying to determine the variations in nuclear decay over time measured by several people, for example Baurov http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=21399929 Jere Jenkins http://arxiv.org/abs/1106.1470 The measurements are done in central Stockholm, Sweden. I hope to improve this experiment over time. Right now I am just doing preliminary trivial measurements. If anyone could donate one or several better radiation counters to me I would be happy. David David Jonsson, Sweden, phone callto:+46703000370