Radon Graph #13

One Hour measurements compared to 48 hour CRM Averages

Red dots represent 48 Hour CRM averages
All other color dots represent one hour measurements taken at the 6th, 12th, 18th, 24th, 30th, 36th, and 44th hour of monitoring.
94.4% of the one hour measurements will accurately indicate if the 48 hour average will be above or below 4 pCi/l.
87.5% of the one hour tests will be withen 1 pCi/L of the 48 hour average on tests averaging below 6.1 pCi/L.

1001 One hour measurements compared to 143 two day CRM averages
41 one hour measurements tested below 4 pCi/L on homes averaging above 4 pCi/L ( 4% false negative )
No house averaging above 6.1 pCi/L had a one hour measurement below 4 pCi/L
16 one hour measurements tested above 4 pci/L on homes averaging below 4 pCi/L ( 1.6% false positive )
No house averaging below 2.4 pCi/l had a one hour measurement test above 4 pCi/L