As a definitive and unambiguous indicator of a nuclear underground explosion

the noble gas of 37Ar is an important nuclide for on-site inspections under the CTBTO (Comprehensive Nuclear-Test-Ban Treaty Organization). The Institute of Nuclear Physics and Chemistry has developed the movable 37Ar rapid detection system (MARDS) for on-site inspections

in which low level decay counting method is employed for 37Ar activity measurement. Because no stand is available for 37Ar activity measurement

comparison of the 37Ar activity measurement is necessary. In this paper

comparison measurement between INPC and Division of Climate and Environmental Physics

Physics Institute

University of Berne (KUP) is reported. The results show that the method used in MARDS is of great reliability in 37Ar activity measurement. This work can enhance the trust of CTBTO for MARDS and support the potential application of MARDS in on-site inspections.