This document specifies a test method to determine radium-226 (²²⁶Ra) activity concentration in all types of water by emanometry.

The test method specified is suitable for the determination of the soluble, suspended and total ²²⁶Ra activity concentration in all types of water with soluble ²²⁶Ra activity concentrations greater than 0,02 Bq l⁻¹.

The decay chains of ²³⁸U and ²³²Th are given in Annex A. Figure A.1 shows the ²³⁸U and its decay chain.