ISO 13164-4:2015描述了通过萃取和液体闪烁计数测定非盐水中氡-222（222Rn）活性浓度的试验方法。 氡-222放射性浓度至少高于0.5 Bq l，可通过使用现有仪器的本试验方法进行测量−1对于10毫升的试样，测量时间为1小时。 本试验方法可成功用于饮用水样品，实验室有责任确保本试验方法适用于未经试验基质的水样。 附录A给出了满足饮用水监测所需检测限的必要计数条件。

This document describes a test method for the determination of radon-222 (222Rn) activity concentration in non-saline waters by extraction and liquid scintillation counting. The 222Rn activity concentrations, which can be measured by this test method utilizing currently available instruments, are above 0,5 Bq·l−1 which is the typical detection limit for a 10 ml test sample and a measuring time of 1 h. It is the responsibility of the laboratory to ensure the validity of this test method for water samples of untested matrices. Annex A gives indication on the necessary counting conditions to meet the required detection limits for drinking water monitoring.