Routine Use of Ionization Chamber Method for C14 Assay

Abstract
The design and routine use of apparatus for the measurement of amounts of C14 down to a specific activity of the order of 10−9 curie per gram is described. Use is made of an ionization chamber containing the sample to be analyzed (as CO2) and a Lindemann electrometer. The auxiliary electrometer circuits and the apparatus for handling the CO2 gas are also presented. The method is in regular use in the radiation laboratory for the routine analysis of samples obtained from biological tracer experiments. A comparison with other methods of C14 detection is included.