Calibration and consistency of results of an ionization-chamber secondary standard measuring system for activity

Calibration in terms of activity of the ionization-chamber secondary standa rd measuring systems at the PTB is described. The measurement results of a Centronic IG12/A20, a Vinten ISOCAL IV and a radionuclide calibrator chambe r for nuclear medicine applications are discussed, their energy-dependent e fficiency curves established and the consistency checked using recently eva luated radionuclide decay data. Criteria for evaluating and transferring ca libration factors (or efficiencies) are given. (C) 2000 Elsevier Science Lt d. All rights reserved.