Anthropomorphic models for checking the calibration of whole-body counters and activation analysis systems

Three models of the human body have been made for checking the calibration of whole-body counters and activation analysis systems. Their weights are 41, 67 and 110 kg. Each contains simplified forms of lungs, bones, thyroid, kidneys and liver and has a chemical composition similar to that of the ICRP standard man. In addition traces of toxic elements such as Cd and Hg have been included in various organs. The composition of the manikins has been measured at four centres where activation analysis in vivo has been carried out. The potassium contents have been measured at three other centres. Differences between measured and actual contents have often been much larger than quoted uncertainties of the measurements, 20-50% for Na, Cl and P. For K, differences did not exceed 17% but are still often greater than the expected uncertainty. The greatest errors usually occurred with the smallest manikin.