Outcalt Stephanie L
National Institute of Standards and Technology, Boulder, CO 80305, USA.
J Res Natl Inst Stand Technol. 2018 Oct 9;123:1-10. doi: 10.6028/jres.123.017. eCollection 2018.
Data on the calibration fluids water and toluene individually, and the combination of those two sets of data, were correlated with two different equations (resulting in six sets of calibration equation parameters) to analyze data measured with a vibrating-tube densimeter on the lubricants pentaerythritol tetrapentanoate (POE5), pentaerythritol tetraheptanoate (POE7), and pentaerythritol tetranonanoate (POE9) at temperatures from 270 K to 470 K and pressures from 0.5 MPa to 50 MPa. The objective was to explore how the calculated densities of the lubricants would differ based on the calibration equations and calibration fluid(s). The viscosities of the measured lubricants are much greater than those of the calibration fluids, and because there has long been a question of how measurements of higher viscosity fluids are affected when measured with a vibrating-tube densimeter, combinations of calibration fluid(s) and equations were tested to explore the role they play in obtaining accurate results. For the lubricants studied herein, more accurate results were obtained with a calibration fitted to multiple calibration fluids, while the consistency of results was more equation dependent.
分别获取了校准流体水和甲苯的数据，以及这两组数据的组合，并将其与两个不同的方程相关联（得出六组校准方程参数），以分析使用振动管密度计在270 K至470 K的温度和0.5 MPa至50 MPa的压力下对润滑剂季戊四醇四戊酸酯（POE5）、季戊四醇四庚酸酯（POE7）和季戊四醇四壬酸酯（POE9）进行测量得到的数据。目的是探究基于校准方程和校准流体，润滑剂的计算密度会有怎样的差异。所测润滑剂的粘度远大于校准流体的粘度，并且长期以来一直存在一个问题，即使用振动管密度计测量较高粘度流体时，测量结果会受到怎样的影响，因此对校准流体和方程的组合进行了测试以探究它们在获得准确结果中所起的作用。对于本文研究的润滑剂，使用拟合多种校准流体的校准方法可获得更准确的结果，而结果的一致性则更依赖于方程。
