refractometer index

例句：

1. 1.The refractometer index of the sample is 1.50.
   样品的折射计指数是1.50。
2. 2. The refractometer index is used to measure the refractive index of materials.
   折射计指数用于测量材料的折射率。
3. 3. The refractometer index is an important parameter in the study of optical phenomena.
   折射计指数是研究光学现象的重要参数。