A survey of the accuracy of dose calibators at Sydney hospitals

Results of a survey conducted in February 1985 to assess the accuracy of dose calibrations for 10 hospitals in the Sydney area are presented. The assessments were conducted by measuring samples of 131I, sup(99m)Tc, 67Ga and 201Tl in an ionization chamber, previously calibrated with absolute standards of known radioactivity, and the comparing the results with those from the hospital dose calibrators. Most of the dose calibrators surveyed gave results which were within +-10% of the radioactivity of the standard, the exception being the Victoreen Calrad instrument which gave consistently inaccurate results