Rudjer Bošković Institute Radiocarbon Measurements II

Dušan Srdoč, Adela Sliepčevic, Josip Planinic, Bogomil Obelic, Branko Breyer
1973 Radiocarbon: An International Journal of Cosmogenic Isotope Research  
The present list contains dates of samples measured since our previous list (R., 1971, v. 13, p. 135–140). As before, age calculations are based on the Libby half-life 5568 ± 30 yr, and reported in years before 1950. The modern standard is 0.950 of the activity of NBS oxalic acid, giving a net counting rate of 21.68cpm. The background count is measured by a series of inactive samples such as marble, anthracite, petroleum coke, and old natural methane. Background count of these samples give a
more » ... e samples give a mean value of 6.05cpm. It is observed that marble always gives the highest value of background count while natural methane gives the lowest. Results, however, are within ± 1σof the mean value.
doi:10.1017/s0033822200001314 fatcat:tpjcd6mjgrb5dg43oiqh544jke