Abbe Refractometer This instrument is designed for the measurement of refractive index( nD) and the average optical dispersion( NF-NC) of the transparent, the semitransparent and the solid matter ( mostly transparent) . It was connect with a circulating thermostatic bath, can measure the refractive index in 0 ~ 50 . It also measures the Brix percentage of sugar solution[ ( 0-95) which is equal to th refractive index1.333-1.531] . It was widely used in oil industry, fat industry, pharmaceutical factories, paint, food processing, chemistry, sugar refineries, geologic etc., and relative factories, school and research center.