title: Activity measurement of 85Kr diluted by a large volume balloon technique.
abstract: The National Metrology Institute of Japan (NMIJ) participated in the CCRI(II) Key-comparison of (85)Kr activity measurement. The absolute internal gas-counting method was used, with a set of proportional counters of different length. The original (85)Kr gas was diluted by a factor of 2x10(5) in order to achieve the suitable activity concentration for the proportional counters. A new dilution method was introduced, based on a large-volume balloon and gravimetric determination of the dilution volume with small uncertainties.
authors.affiliation: National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan. a.yunoki@aist.go.jp
authors.forename: Akira
authors.initials: A
authors.lastname: Yunoki
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamada
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kawada
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Unno
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sato
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Hino
mesh_terms: D019411:Clinical Laboratory Techniques / Q000592:standards; D004784:Environmental Monitoring / Q000379:methods; D005740:Gases / Q000032:analysis; D007564:Japan; D007727:Krypton Radioisotopes / Q000032:analysis*; D008722:Methods; D035501:Uncertainty; D014894:Weights and Measures
chemical_list: D005740:Gases; D007727:Krypton Radioisotopes