The author investigated the use of commercially available continuous radon monitors (CRM’s) and S-Chamber E-PERM’s® using short term electrets to measure the 222 radon and 220 thoron emanation from concrete and granite counter tops. The performance of CRM’s and E-PERM’s® placed in 3 to 23 liters metal accumulator chambers sealed to a building material were compared to the total emanation rate of the building material when the material was placed in a sealed 122 liter chamber. Concrete slabs were constructed that had radon only versus 222 radon and 220 thoron and 219 action to determine the test equipment response to these isotopes. A thoron chamber was constructed to test the detectors response to thoron and the reduction in response to thoron when the detectors were placed in diffusion barriers. Accumulator and sealed chamber tests on three different granites found significant variation in emanation rates depending on what side of the granite was tested.
Bill Brodhead
WPB Enterprises, Inc., 2844 Slifer Valley Rd., Riegelsville, PA USA
wmbrodhead@gmail.com, www.wpb-radon.com