The refractive index nD of liquids and solids and the mass fraction of dry solids in the sugar solution, namely Brix, are measured, using visual aiming and backlit liquid crystal display. The temperature can be corrected by measuring the hammer. The prism is made of hard glass, which is not easy to wear. Equipped with RS232 interface, it can transmit data to PC. The main technical parameters: Measuring range (nD): 1.3000-1.7000 Measurement accuracy (average value): refractive index nD ±0.0002 Measurement resolution: 0.0001 The mass fraction of sucrose solution (Brix) display range: 0~100% Measurement error (Brix): ±0.1% Measurement resolution (Brix): 0.1% Temperature display range: 0℃~50℃ Output mode: RS232 Power supply: 220V~240V, frequency 50Hz±1Hz Apparatus dimensions: 330㎜×180㎜×380㎜ Instrument weight: 10kg