Reich H
Phys Med Biol. 1979 Sep;24(5):895-900. doi: 10.1088/0031-9155/24/5/002.
With the introduction of SI units in radiology the quantity exposure will probably be abandoned for therapy level dosemeters because of the inconvenient conversion factors which have, in SI units, to be applied for the change into absorbed dose. Instead of exposure, a quantity is envisaged which, like absorbed dose, is measured in the unit gray (= joule per kilogram). A difficulty lies in the fact that in the immediate future only primary standards of exposure will be available, necessitating the introduction of conversion factors at the interface between primary and secondary standards or field instruments. Expert opinion differs as to whether a kerma quantity, a half-way stage to the desired situation, should be used, or whether the full step should be taken involving the calibration of field instruments in terms of 'absorbed dose in water under specified conditions'. This paper discusses the problem and recommends the full step.
随着放射学中国际单位制（SI）的引入，由于在SI单位制中，将照射量转换为吸收剂量时需要应用不便的转换因子，因此治疗级剂量计可能会摒弃照射量这个量。设想用一个与吸收剂量类似的量来替代照射量，该量以单位戈瑞（=每千克焦耳）来度量。困难在于，在不久的将来，仅有照射量的原级标准可用，这就需要在原级标准与次级标准或现场仪器之间的接口处引入转换因子。对于是应该使用比释动能这个量（这是朝着理想情况的一个中间阶段），还是应该直接迈出全面的一步，即按照“特定条件下水中的吸收剂量”对标定现场仪器，专家们存在不同意见。本文讨论了这个问题并建议采取全面的一步。
