| Abstract: | Conclusions High accuracy can be obtained with the relative method of determining -radiation activity on a scintillation counter only when the samples are precisely positioned, especially for small distances between the source and the radiation detector. Because of the low levels of activity of the standards (approximately 0.5 Ci) SSGS must be calibrated for small distances between the source and the detector. Additional measurements taken with the source rotated through 180 greatly reduce the systematic error caused by inaccurate positioning. A large scintillation crystal of NaI(T1) used as a detector reduces systematic error in relative measurements owing to the sources shifting from the detector axis and to variations in the dimensions of the radioactive spots of different sources.Translated from Izmeritel'naya Tekhnika, No. 2, pp. 77–80, February, 1971. |
