Several correction factors for primary beta dosimetry in radiation protection have been determined by means of measurements and simulations for both the well-known Bhm primary standard extrapolation chamber developed at PTB (which has been commercially available for a long time) and a new primary standard extrapolation chamber also developed at PTB. The correction factors k _el for electrostatic attraction of the entrance window due to the collecting voltage and k _sat for ionisation collection losses due to ionic recombination have been measured. The following correction factors have been determined by simulations for normal (0) as well as oblique (15, 30, 45 and 60) radiation incidence: k _ba for backscatter from the collecting electrode, k _pe for perturbation by the chamber’s side walls, and k _ra, k _ac and k _di for inhomogeneity inside the collecting volume. The latter three have been combined to k _ih. Six more correction factors adopted from the literature are described to complete the necessary corrections. A comparison with values given in ISO 6980-2:2004 (for 0), all determined at that time by means of measurements, is shown as well as the application of the new factors to measured data. The newly determined correction factors are ready to be implemented in an updated version of ISO 6980-2.

通过对PTB开发的著名的Bhm一级标准外推室（已长期商用）和新的一级标准外推进行测量和模拟，确定了辐射防护中初级β剂量测定的几个校正因子。 PTB也开发了暗室。已经测量了由于收集电压引起的入射窗的静电吸引的校正因子k _el和由于离子重组引起的电离收集损失的k _sat。通过模拟法线（0）以及斜线（15、30、45和60）的辐射入射，可以确定以下校正因子：k _ba对于从收集电极的反向散射，k _pe用于干扰腔室的侧壁，k _ra，k _ac和k _di用于收集室内的不均匀性。后三个已合并为k _ih。描述了从文献中采用的另外六个校正因子，以完成必要的校正。显示了与当时通过测量确定的ISO 6980-2：2004（对于0）中给出的值的比较，以及新因子在测量数据中的应用。新确定的校正因子已准备好在ISO 6980-2的更新版本中实施。