Intercomparison of ionization chamber calibration factors in the IAEA/WHO network of SSDLS

In 1995 an intercomparison of ionization chamber calibration factors was performed. It was open to Member laboratories within the IAEA/WHO Network of SSDLs. The aim of this exercise was to test a new quality audit system for these laboratories. The intercomparison has 17 participating laboratories; calibration factors for 24 ionization chambers were checked. The participants were asked to calibrate the ionization chambers both in terms of air kerma and absorbed dose to water. The results show that most of the SSDLs perform air kerma calibration of acceptable quality, while some misunderstandings regarding calibrations in terms of absorbed dose to water were discovered. This type of intercomparison will from now on become a normal service of the Network secretariat in collaboration with the IAEA dosimetry laboratory. It will be expanded to cover all Member laboratories which perform therapy level ionization chamber calibrations as part of their normal service. (author). 6 refs, 3 figs, 1 tab