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Comparison of NIST and manufacturer calibrations of 90 Sr+ 90 Y ophthalmic applicators
Author(s) -
Soares C. G.
Publication year - 1995
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.597416
Subject(s) - nist , calibration , dosimetry , nuclear medicine , physics , range (aeronautics) , nuclear physics , nuclear engineering , medical physics , medicine , computer science , engineering , aerospace engineering , quantum mechanics , natural language processing
Since the resumption of the NIST calibration service for 90 Sr+ 90 Y beta‐particle ophthalmic applicators, 65 sources have been calibrated using the revised technique [C. G. Soares, Med. Phys. 18 , 787–793 (1991)]. For 59 of these sources, the manufacturer's calibration results were available for comparison to the NIST calibration results. The 59 sources represent eight different manufacturers, only one of which is still selling new sources. Manufacturer calibration dates range from the present back to 1954. The results of the comparisons are presented, broken down by both manufacturer and calibration date; there are interesting and significant trends in both, with average differences of 20% not uncommon. The obsolete unit, “roentgen‐equivalent‐beta” (reb), in which some of the manufacturer calibrations are expressed, is discussed, and a factor (0.00982 Gy reb −1 ) for its conversion to absorbed dose is suggested.