The Research For Refractometer Based On Liquid Prism

Refractive index is a physical quantity which used to characterize the liquid’s optical properties.It can use for analyzing density, concentration, temperature and other physical quantities. At present,the measuring range of the Abbe refractometer is from1.3000to1.7000in China and abroad. Withthe appearance of the new liquid material such as ionic liquid, liquid crystal, liquid polymer and soon, and the increasing of the range of the liquid’s refractive index, Abbe refractometer can not fullysupply the demands at present. Although some foreign refractometer can measure the refractiveindex greater than2, but the price of up to hundreds of thousands. Thus the market need for lowcost, large measuring range refractometer.This paper first presents a liquid variable-angle Prism and shows two liquid-based prismsrefractometer: visual analyzer and digital refractometer. It describes the system structure, lightingand the corresponding principle of the liquid refractive index measurement of the designed liquidprism refractometer. Depending on the refractive index range of different liquid prism apex angle, itshows the potential use of the liquid variable-angle Prism. The optical system of the visual liquidprism monocular and binocular refractometer is designed by ZEMAXsoftware. In the end, principleexperiments research is done by the CSY10L laser multifunction optical test system. This theory isfound to be in line with the experimental results.Theoretical results show that the refractometer has bigger measure range, simpler structure,lower cost and greater accuracy than Abbe refractometer. It’s easy to get the product out of thelaboratory and it has the value of the practical application. Theoretical analysis shows that thisrefractometer has a wide refractive index measurement range (1.0000～3.8600) when the liquidprism apex angle is30degree. Its measurement range is only related with the liquid prism apexangle, and the use of monochromatic light source, reducing the influence of dispersion and higheraccuracy.