Refractive index definition:
When light enters another transparent medium from a transparent medium, it produces a refraction phenomenon caused by the different speeds of light in various media. Refractive index is the ratio of the speed at which light travels through air to the speed at which it travels in other materials.
It can be used to determine the refractive index of liquid, the solute content in solution, the sugar content of wine, the water content in high sugar solution, the salinity of seawater and the specific gravity of battery electrolyte. Widely used in petrochemical, light industrial food, medical and health and environmental protection and greening industries.