本文介绍60~250kV X射线照射量的绝对测量方法，给出各种修正因子的确定结果，估计复现伦琴的不确定度为1.8%，长期重复测量的标准偏差为±0.1%。

The X-ray exposures in unit of C.kg

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or Röentgen were measured by a parallel—plate free air ionization chamber. The plate distance was 20.9cm. The length of collector was 10cm. The correction factors were determined. The uncertainty of measurement was about 1.8% for 60~250kV X-rays. The long-term standard deviation was ±0.1%.