Model of BF3 neutron proportional Geiger counter
1954
1954
1888
1964-1978
1955
1883-1888
1950-1960
1960
1944
1958
1950-1970
1963
1965
1790-1819
1790-1819
1960-1965
1964-1978
1973
1948
1966
1952
1930
1966
1900-1980
1966