標準號：SIS SS-ISO 489-1987
中文標準名稱：塑料．半透明塑料折射率判定
英文標準名稱：Plastics - Determination of the refrac- tive index of transparent plastics
發布日期：1987/9/15 12:00:00
實施日期：1999/12/31 12:00:00
適用范圍：1.1 This International Standard specifies two methods of test for determining the refractive index of transparent plastics, namelyMethod A: Refractometric method for measuring the refractive index of transparent cast, moulded or sheet materials by means of a refractometer. The method is recommended when great accuracy is required. It is not ap-plicable to powdered or granulated transparent materials.Method B: Immersion method (Becke line phenomenon) for determining the refractive index of powdered or granulated transparent materials by means of a microscope and making use of the Becke line phenomenon. Monochromatic light should, in general, be used to avoid dispersion effects. The accuracy of this method is about the same as that of method A.1.2 Refractive index is a fundamental property which can be used for the control of purity and composition, for the iden-tification of materials and for the design of optical parts.The change of refractive index with temperature may give an indication of transition points of materials.