ISO 11665-9:2019

ISO 11665-9:2019 is an international standard that details a method for determining the free radon exhalation rate of building materials. Specifically, it focuses on measuring the exhalation of Radon-222 (222Rn) using Liquid Scintillation Counting (LSC) or gamma ray spectrometry. The standard also clarifies that the exhalation of Thoron (220Rn) does not interfere with the test results.