Abstract: We analyzed the problems existing in the practical application of current standard measurement methods forwater sample gross α and gross β radioactivity in China, and proposed the corresponding solutions. It turns out that: 1) The time interval between sample collection and preparation, and between sample preparation and measurement, are not prescribed. For samples with a higher ²²⁴Ra content such as groundwater or rock formation seepage, the analysis should be performed as soon as possible within 48h after sampling, to accurately determine their gross α levels. 2) For samples with a higher amount of residue, which may affect themeasurement accuracy, the detection limit can be reduced by extending the measurement time and using largermeasuring disks. 3) αsources used to determinethe α, βcrosstalk ratio of measuring instruments are not specified. To avoid the crosstalk ratio difference caused by the use of different alpha sources, low background measuring instruments with a relatively low crosstalk ratio, such as those with a build-in solid scintillator or semiconductor detector, can be employed. In addition, aluminum foil, paper, etc. can shield α rays and reduce the influence of α channel on β channel.

Key words: Gross α, Gross β, Water sample analysis