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(Mis)use of 133Ba as a calibration surrogate for 131I in clinical activity calibrators



Brian E. Zimmerman, Denis E. Bergeron


Using NIST-calibrated solutions of 131Ba and 131I in the 5 mL NIST ampoule geometry, measurements were made in three NIST-maintained Capintec activity calibrators and the NIST Vinten 671 ionization chamber to evaluate the suitability of using 133Ba as a calibration surrogate for 131I. For the Capintec calibrators, the 133Ba response was a factor of about 3 times higher than that of the same amount of 131I. For the Vinten 671, the Ba-133 response was about 7 % higher than that of 131I. These results demonstrate that 133Ba is a poor surrogate for 131I. New calibration factors for these radionuclides in the ampoule geometry for the Vinten 671 and Capintec activity calibrators were also determined.
Applied Radiation and Isotopes


activity calibrators, barium-133, iodine-131, ionization chambers


Zimmerman, B. and Bergeron, D. (2016), (Mis)use of 133Ba as a calibration surrogate for 131I in clinical activity calibrators, Applied Radiation and Isotopes, [online], (Accessed July 17, 2024)


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Created March 1, 2016, Updated February 19, 2017