26th – 27th July, 2011


Heavy rain last night at about 11:40PM till about 12:15AM.

For those readers who have visited the Radiation Network map and wonder how this information relates to the numbers in the little circles on their map here is an explanation:
The numbers on the map are in Counts-per-Minute (CPM) units. Meaning how many “clicks” of the geiger counter are received each minute. μRoentgens/hr (the units used in my data are roughly equivalent to CPM for my geiger tube. ie: 15μR/hr equals 15.75 CPM. So when they say the warning level is 100CPM a reading of 105μR/hr would be equivalent. If you watch the map refresh for a few minutes you will notice that the readings change at a given circle. This means that if you happen to view the map when the reading is at 33 CPM, that’s what you take away. However you may view it when it is reading 23CPM so unless readings are consistently high you can’t extrapolate to the whole day’s background from one viewing of the map.
That is why in the above charts my data is presented as 60 minute averages. Meaning that each point is the average reading for the past hour from that time. This gives a good idea of what is going on with the radiation trends.
Below is a chart of today’s data presented as one minute readings (the same type of data on the Radiation Network map. Notice that there are spikes of over 100. Compare the chart at the top of this page with this one.

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