We report speeds of sound in n-pentane measured using two similar apparatus, located at Ruhr University Bochum (RUB) and Imperial College London (ICL), covering different ranges of temperature and pressure. At RUB, measurements were conducted at temperatures from 233.50 to 353.20 K with pressures up to 20 MPa, while temperatures from 263.15 to 473.15 K with pressures up to 390 MPa were covered at ICL. Accounting for the uncertainties in temperature, pressure, path-length calibration, and pulse timing, the relative expanded combined uncertainty (k = 2) in the speed of sound varied from 0.015 to 0.18% over the whole region investigated. Nevertheless, small differences averaging at 0.13% are found between the two data sets in the region of overlap. The experimental data reported in this work have been partly used in the development of a new fundamental equation of state for n-pentane.

中文翻译：

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在声音的速度ñ戊烷在从233.50到温度473.15处的K压力达到390兆帕

我们报告了使用位于波鸿鲁尔大学（RUB）和伦敦帝国理工学院（ICL）的两个类似装置测量的正戊烷中的声速，涵盖了不同的温度和压力范围。在RUB，测量在233.50至353.20 K的温度下进行，压力最高为20 MPa，而在263.15至473.15 K的温度下，压力最高为390 MPa进行测量。考虑到温度，压力，路径长度校准和脉冲时序的不确定性，相对扩展的组合不确定性（k= 2），在整个研究范围内，声速从0.015到0.18％不等。但是，在重叠区域的两个数据集之间发现了平均为0.13％的小差异。这项工作中报告的实验数据已部分用于开发新的正戊烷基本状态方程。