Published online by Cambridge University Press: 18 July 2016
C14 measurements of archaeologic and geochemical samples using sample synthesized benzene in a Beckman LS-100 liquid scintillation spectrometer are reported. Rather high background counting rates of ca. 8 to 9 cpm and counting efficiency of ca. 45 to 48% for 4 cc counting vial of potassium free glass are observed. The counting vial (total volume of 10 cc) is supported by an aluminum bar for geometry control. Background and standard counting rates measured during the past 17 months are listed in Tables 1 and 2, respectively. Slight seasonal variations were observed.