Measurement of Density Inhomogeneity for Source Masses in Time-of-Swing Method of Measuring G

• 来源期刊: 中国物理快报(英文版)
• 年，卷（期）: 2009,（1）
• 页码范围: 36-39
• 页数: 4页
• 语种: 英文

摘要

A method with scanning electron microscopy (SEM) is presented to measure the density inhomogeneity of the stainless steel (SS316) sphere prepared for measuring G using time-of-swing method. The experimental result shows that the relative density inhomogeneity of the sphere is better than 5.9 × 10-4 over the volume of 0.272 × 0.234 × 0.005 mm3. If we assume that the density inhomogeneity of the spheres used in our G measurement is the same as that of the sphere destroyed in testing, it will contribute to G value with an uncertainty of less than O.034 ppm in our G measurement. Furthermore, the mass centre offset from the geometric centre of the sphere will be less than 4.3 × 10-4 μm due to this inhomogeneity.