1.1这些试验方法包括测定电容器、变压器、断路器和充油电缆中使用的电绝缘液体的折射率和特定光学色散。 1.2描述了两种测试方法，一种是常规方法，另一种是更精确的裁判方法。这两种方法都适用于透明、浅色的绝缘液体。 1.2.1常规方法用于测定这些试验方法中所述的折射率和比色散。 1.2.2当需要进行高精度测试时，使用裁判法。测试方法中描述了这些方法 D1218 . 通过除以试验方法中确定的折射色散值来计算比光色散 D1218 通过相对密度（比重）（见试验方法 D1298号 )被测液体的浓度。 1.3以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 1.4 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全和健康实践，并确定监管限制的适用性。 ====意义和用途====== 折射率 — 绝缘液体的折射率随其成分、溶液中污染物的性质和数量而变化。折射率随时间和服务的变化可作为估计服务中获得的成分或污染程度变化的基础。 对于电绝缘矿物油，波长为5893 ˚ 通常使用A表示钠的光谱线。测试温度为25 ° C 比色散 — 特定光色散可作为油中不饱和化合物含量的快速指标。石蜡和环烷化合物的分散值几乎相同，基本上与分子量和结构差异无关。高于97的值与绝缘油中存在的芳香化合物的数量有直接关系。为了方便起见，将比色散值乘以10 4. . 对于电绝缘矿物油，波长为6563和4861 ˚ 通常使用与氢谱线对应的A。 或者，6678和5016的波长 ˚ 可以使用对应于氦谱线的A。

1.1 These test methods cover the determination of the refractive index and the specific optical dispersion of electrical insulating liquids such as are used in capacitors, transformers, circuit breakers, and oil-filled cables. 1.2 Two test methods are described, a routine method and a more precise referee method. Both methods are applicable to transparent, light-colored, insulating liquids. 1.2.1 The routine method is used to determine refractive index and specific optical dispersion as described in these test methods. 1.2.2 The referee method is used when a test of high accuracy is desired. These methods are described in Test Method D1218 . Specific optical dispersion is calculated by dividing the refractive dispersion value determined in Test Method D1218 by the relative density (specific gravity) (see Test Method D1298 ) of the liquid under test. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 This standard does not purport to address all of the safety concerns, 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. ====== Significance And Use ====== Refractive Index — The refractive index of an insulating liquid varies with its composition and with the nature and amount of contaminants held in solution. Changes of refractive index with time and service may form a basis for estimating any change in composition or the degree of contaminant acquired in service. For electrical insulating mineral oils, the wavelength of 5893 ˚ A for the spectral line of sodium is commonly used. The test temperature is 25 ° C. Specific Optical Dispersion — Specific optical dispersion serves as a quick index to the amount of unsaturated compounds present in an oil. Dispersion values for paraffinic and naphthenic compounds are nearly the same and are essentially independent of molecular weight and structural differences. Values above 97 bear a direct relationship to the amount of aromatic compounds present in insulating oil. For convenience, the specific dispersion value is multiplied by 10 4 . For electrical insulating mineral oils, the wavelengths of 6563 and 4861 ˚ A corresponding to the spectral lines of hydrogen are commonly used. Alternatively, the wavelengths of 6678 and 5016 ˚ A corresponding to the spectral lines of helium may be used.