SECONDARY STANDARD INSTRUMENTS FOR ACTIVITY MEASUREMENT OF PURE BETA EMITTERS A REVIEW

This paper reviews the use of calibrated ionisation chambers and counters for the standardisation of the activity of pure or nearly pure beta emitters with maximum beta energies in the range up to 700 keV approximately. With minor exceptions, only those instruments are considered which permit the attainment of reproducibilities well within ±2 per cent and their designs are discussed for their stability, sensitivity and ease of operation. So far no instrument combines these three characteristics in a really satisfactory manner but further improvements seem possible, and would be desirable. © 1969.