【摘要】 本文叙述了一个用于测定呼气的改良型双滤膜装置。改良型双滤膜装置是在通用型双滤膜装置上加入了一个气溶胶输给系统,因而显著降低了原装置的壁吸附,大大提高了灵敏度。根据本文采用的程序能测出²³²Th 在人体内最大容许体负荷量的0.03%。本方法不但能测定呼气（气土）,还可以测定环境空气中的氡、（气土）浓度。本文详细介绍了该装置的原理、设备、计算方法以及测定结果。更多还原

【Abstract】 A modified double filter device for measuring the thoron in exhaled air is described.An aerosol supply system was added to the common double filter system.It greatly reduced deposition on the wall of the previous device so that it significantly increased its sensitivity.Using the procedure presented in this paper,0.03% of the maximum permissible body burden of thorium can be measured.This method can be used for measuring not only the thoron in exhaled air,but also the radon and thoron in environmental air.The principle,equiPment,calculation method and measuring results are described in detail.更多还原