The radiocarbon (14C) dating facility at the Centre for Isotope Research, University of Groningen went through a major upgrade in 2017 and this included installation of a MICADAS accelerator mass spectrometer (AMS). In the first 18 months, we performed 4000 sample and 3000 reference measurements. A careful evaluation of those measurement results is presented, to characterize the various sources of uncertainty and to ultimately assign, for every sample measurement, a realistic expanded uncertainty. This analysis was performed on the measurements of secondary references and sample duplicates in various phases of their processing steps. The final expanded uncertainty includes both the 14C measurement uncertainties and uncertainties originating from pretreatment steps. Where the 14C measurement uncertainty includes straightforward uncertainties arising from Poisson statistics, background subtraction, calibration on Oxalic Acid II and δ13C correction, the uncertainties originating from pretreatment steps are based on the spread of actual measurement results for secondary references and sample duplicates. We show that the 14C measurement uncertainty requires expansion, depending on the number of processing steps involved prior to a 14C measurement, by a maximum factor of 1.6 at our laboratory. By using these expansion (multiplication) factors, we make our reported uncertainty both more realistic and reliable.

中文翻译：

---

使用新一代高产加速器质谱仪对放射性碳分析的不确定性进行独立评估

放射性碳 (14C) 格罗宁根大学同位素研究中心的测年设施在 2017 年进行了重大升级，其中包括安装 MICADAS 加速器质谱仪 (AMS)。在前 18 个月，我们进行了 4000 个样本和 3000 个参考测量。对这些测量结果进行了仔细评估，以表征各种不确定性来源，并最终为每个样品测量分配一个现实的扩展不确定性。该分析是在其处理步骤的各个阶段对二级参考和样品副本的测量进行的。最终扩展的不确定性包括14C 测量不确定性和源自预处理步骤的不确定性。在哪里14C 测量不确定性包括泊松统计、背景扣除、草酸 II 和 δ 校准产生的直接不确定性13C 校正，源自预处理步骤的不确定性基于二次参考和样品重复的实际测量结果的分布。我们证明了14C 测量不确定度需要扩展，具体取决于在测量之前涉及的处理步骤的数量14C 测量，我们实验室的最大系数为 1.6。通过使用这些扩展（乘法）因子，我们使我们报告的不确定性更加现实和可靠。