Taken with a sun nuclear model 1027.
The data is read from left to right and each data point represents one hour of testing.
These were taken 6 minutes apart and the second tape was taken just before the last hour data point was recorded. Note the very different averages. I think the machine started to average the results in the electronics just before the last hour was integrated and recorded.
The graph immediately got my attention. I have not seen this shape of graph with such distinct spikes. When the homeowner was asked about laundry, the time frames that washing was done coincides with these spikes.
These results were printed within minutes of each other after hour #48. Note the very different averages and also note the last hour with a radon measurement of 500 pCi/L.
this shows the data points before and after hour #48. Note the different values recorded for the hours shown.
Has anyone else ever seen something like this?