Papp Z, Daróczy S
Isotope Laboratory, Kossuth University, Debrecen, Hungary.
Health Phys. 1997 Apr;72(4):601-10. doi: 10.1097/00004032-199704000-00012.
A new grab sampling method has been developed for the simultaneous measurement of radon decay products and thoron decay products in air. It is based on direct beta counting of filtered aerosol sample over successive time intervals by end-window Geiger-Muller counter. Defined solid angle absolute counting was used to evaluate the efficiencies for the decay products one by one. Absolute activity concentrations can be determined with less than 10% systematic error. Glass-fiber filter, high sampling flow rate, and long duration of sampling can be used, as a result of which the detection limits are about 0.1, 0.2, and 0.01 Bq m(-3) for 214Pb, 214Bi, and 212Pb, respectively. Indoor saturated activity concentrations were measured in 86 buildings in Ajka town, Hungary, where industrial wastes rich in uranium had been used as building materials. Elevated radon decay product levels were found in houses built before 1960. Radon gas concentration was also measured simultaneously in 26 cases and the minimum, maximum, and average values of the equilibrium factor were 0.17, 0.73, and 0.40, respectively.
已开发出一种新的采集采样方法，用于同时测量空气中的氡衰变产物和钍衰变产物。该方法基于通过端窗盖革 - 米勒计数器对过滤后的气溶胶样品在连续时间间隔内进行直接β计数。使用定义的立体角绝对计数法逐一评估衰变产物的效率。绝对活度浓度的测定系统误差小于10%。由于可以使用玻璃纤维过滤器、高采样流速和长时间采样，因此对214Pb、214Bi和212Pb的检测限分别约为0.1、0.2和0.01 Bq m(-3)。在匈牙利阿伊卡镇的86栋建筑物中测量了室内饱和活度浓度，那里富含铀的工业废物被用作建筑材料。在1960年以前建造的房屋中发现氡衰变产物水平升高。还同时在26个案例中测量了氡气浓度，平衡因子的最小值、最大值和平均值分别为0.17、0.73和0.40。
