Abstract
In liquid scintillation measurement, counting rate is affected not only by the quenching but also by other causes such as nonhomogeneity of specimen and chemiluminescence. In this work, a method is presented to detect the affected samples automatically by using the double ratio technique of which standard curve is approximated with a polynomial of the external standard ratio. The deviation was calculated as the minimum distance from the standard curve to a plot of measured sample, which shows a discrepancy of a sample in the pulse height spectrum of beta-decay nuclides. When the discriminating level was set at 0.02 in the deviation, adsorption of specimen or chemiluminescence could be detected practically. Reliability of the presented method and setting of discriminating level were discussed.
