Improvements in the Use of Silicone Oils for the Determination of Glass Refractive Indices

✍ Scribed by J. Locke

• Publisher: Elsevier
• Year: 1982
• Tongue: English
• Weight: 767 KB
• Volume: 22
• Category: Article
• ISSN: 0015-7368
• DOI: 10.1016/s0015-7368(82)71486-0

✦ Synopsis

Commercial batches of silicone oil were investigated as immersion media for comparing glass fragments using a Mettler hot-stage microscope. Refractive Index (RI) changes in the region of 0.0002 occurred with some oils, which reduced the discrimination between glass samples. The instability was traced to a volatile by-product in the oil; a method for removing such impurities by moderate heating on the sample slide is described, together with the procedures necessary to ensure reproducible measurements. The use of silicone oils in conjunction with standard glass samples is described so that the R I of very small (i.e. < lmm) glass fragments can be determined with high accuracy.