Preparation and use of standards for a comparison exercise among users of 131I capsules in South Africa

Two comparison exercises were conducted, one year apart. For each one, four 131I capsules were calibrated using the previously determined calibration factor. These capsule standards were sent to different provinces in South Africa where they were measured by all participating facilities. The results indicated that more than 90% of the participants showed deviations from the certified value of less than 10%.