Standard Test Method for the Automated Determinaton of Refractive Index of Glass Samples Using the Oil Immersion Method and a Phase Contrast Microscope

1.1 This test method covers a procedure for measuring the refractive index of glass samples, irregularly shaped and as small as 300 ug, for the comparison of fragments of a known source to recovered fragments from a questioned source.

1.2 This test method does not include the measurement of optical dispersion or the measurement of refractive index at any other wavelength other than the Sodium D line. This method employs a narrow band pass filter at 589 mm, but other filters could be employed using the described method and allowing the nx' to be determined at other wavelengths, therefore, also allowing for the dispersion value to be calculated.

1.3 Alternative methods for the determination of nx' are listed in Refs (1-5).

1.4 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.