ISO 21395-2:2022 pdf download – Optics and photonics — Test method for refractive index of optical glasses — Part 2: V-block refractometer method. 1 Scope This document specifies a method to determine the refractive index of optical glass with the accuracy within 3 × 10 -5 at the wavelength range from 365 nm to 2 400 nm by using the V-block refractometer method. While this document can be used for non-glass materials, the user is informed that only optical glass has been considered in the development of this document, and other materials can have issues, which have not been taken...