Measurements of the viscosity of pure hydrogen and a binary (hydrogen + methane) mixture with a nominal composition 90 mol % hydrogen are presented. The measurements were conducted with a two-capillary viscometer relative to helium along three isotherms of (298.15, 323.15, and 348.15) K and at pressures of up to 18 MPa. Expanded relative combined uncertainties in viscosity range from (0.65 to 2.7) % (k = 2) for the hydrogen data, and from (0.91 to 3.2) % (k = 2) for the (hydrogen + methane) data. The viscosity data are compared to experimental literature data and viscosity correlations implemented in the NIST REFPROP v10.0 database. Good agreement between this work’s data, literature data, and the viscosity correlation was achieved for pure hydrogen. The (hydrogen + methane) mixture was compared to the Extended Corresponding States (ECS) model implemented in REFPROP v10.0. Relative deviations between the experimental data and the ECS model exceed the experimental uncertainty and were found to exhibit a positive trend with increasing density and a weakly pronounced negative trend with increasing temperature. No experimental literature data are available at overlapping state regions. Nonetheless, deviations to the ECS model imply reasonable consistency of this work’s data and literature data. In addition to experimental viscosities, experimental zero-density viscosity ratios of the fluids under investigation and helium are reported. Fairly good agreement within the experimental uncertainty of this work with a highly accurate literature value and a value obtained from accurate ab initio calculated data was achieved for hydrogen.

给出了纯氢气和标称成分为 90 mol% 氢气的二元（氢气 + 甲烷）混合物的粘度测量结果。测量是使用相对于氦气的双毛细管粘度计沿着（298.15、323.15 和 348.15）K 的三个等温线以及高达 18 MPa 的压力进行的。 对于氢气数据，粘度的扩展相对组合不确定性范围为 (0.65 至 2.7)% ( k = 2)， 对于（氢气 + 甲烷）数据，粘度范围为 (0.91 至 3.2)% ( k = 2)。将粘度数据与 NIST REFPROP v10.0 数据库中实现的实验文献数据和粘度相关性进行比较。对于纯氢，本工作的数据、文献数据和粘度相关性之间取得了良好的一致性。将（氢气 + 甲烷）混合物与 REFPROP v10.0 中实施的扩展对应状态 (ECS) 模型进行比较。实验数据与ECS模型之间的相对偏差超出了实验的不确定性，并且随着密度的增加呈现正向趋势，随着温度的升高呈现较弱的负向趋势。重叠州地区没有可用的实验文献数据。尽管如此，ECS 模型的偏差意味着这项工作的数据和文献数据具有合理的一致性。除了实验粘度之外，还报告了所研究的流体和氦气的实验零密度粘度比。对于氢，本工作的实验不确定性与高度准确的文献值和从准确的从头计算数据获得的值取得了相当好的一致性。