【摘要】 <正> 由于大气环境中氡(气土)浓度比矿井中的浓度低3～4个数量级,因此要求测量方法灵敏度高、本底低以及能在测氡时排除(气土)的干扰,在测(气土)时排除氡的干扰。目前国内测氡普遍采用的活性炭吸附-加热解析-电离室静电计测定方法,不仅速度慢而且操作过程较长,人为影响因素难于控制。其它测(气土)方法如静电计法、闪烁室法、活性炭滤纸法等灵敏度也较低。美国能源研究和发展管理署保健和安全实验室(HASL)的大体积双层滤纸法(ERM-2型及ERM-3型)灵敏度虽较高(0.01pCi/1),但测定时间仍过长,且装置也较庞大。更多还原

【Abstract】 This paper describes a Balloon method for the measurement of radon and thoron in environment. The absolute efficiency was calibrated by a standard radium source and compared with the activated charcoal absorption method. The sensitivity for measurement of radon is rather high (1 × 10-14Ci/l) and quick (the measurement can be done within 25 min.). The sensitivity for measurement of thoron is 1×10-13Ci/l. The installation is simple, and the method is suitable to measure the concentration of the radon and thoron in environmental air.更多还原