利用建立的井型NaI(T1)γ谱仪进行了~(125)I放射性活度的绝对测量,~(125)I放射源由同一批放射性溶液制备,活度范围为10~2~10~4Bq。通过不同强度源的活度测量,得到了~(125)I活度绝对测量中的偶然符合修正系数,该系数的应用使每个源的活度量值更加准确可靠。同时与平面锗探测器的测量结果进行了比对,两套装置测量结果一致性很好,表明井型NaI(T1)γ谱仪的测量结 The radioactivity of 125 I was measured by established NaI (T1) γ spectrometer. The radioactive source of 125 I was prepared from the same batch of radioactive solution with the activity range of 10 ~ 2 ~ 10 ~ 4Bq. Through the measurement of the activity of different intensity sources, the accidental coincidence correction factor in the absolute measurement of ~ (125) I activity was obtained. The application of this coefficient made the activity value of each source more accurate and reliable. At the same time, the results of planar germanium detector were compared. The results of the two sets of devices are in good agreement. It shows that the measurement results of well type NaI (T1) γ spectrometer