Radon is a naturally occurring radioactive noble gas that decays from uranium and radium deposits. 222Rn (T1/2 = 3.8235 days) is dissolved and transported by ground water passing through rocks and soil containing such substances. In a geological system where there are hot springs, sources of natural gas or some crude oil reservoirs it is highly probable that elevated levels of 222Rn in the water occurs.
The RAD-7 detector manufactured by DURRIDGE COMPANY Inc. is utilized to measure radon activity in-air and in-water. The highly handy detector makes use of gated α-spectroscopy to perform the 222Rn activity measurements. This solid state detector has an internal hemisphere of 0.7 l volume. The closed loop aerator process is utilized to extract the 222Rn from the water sample. The RAD-7 detector (RADH2O-kit) can perform a measurement within 30 min with the sensitivity range that matches or exceeds that of the liquid scintillation methods.