Radiometric calorimetry for the quality assurance of radioisotope products

A twin-cup heat-flow microcalorimeter was designed and manufactured in 183 and has been used consistently ever since to make radioactivity measurements on the pure β emitters. For the high energy β emitters and also the lower energy photon emitters absorbers of copper, lead and tungsten were used, tested to ensure that escaping Bremsstrahlung and other electromagnetic radiations were less than 0.1%. It is concluded that microcalorimetry is a potentially safe, accurate and non-destructive technique for measuring activity. It is also economical, since the entire sample can be recovered, a fact which may appeal to commercial suppliers. 9 refs., 3 tabs., 6 figs