What are the factors that affect the measurement results of digital refractometer?
Refractive index is a simple and accurate method to identify the purity of organic compounds. For many binary systems, the refractive index has a fixed relationship with the composition, so it is often used as a parameter to detect the composition. Refractive index is an important optical property of transparent materials. When the refractive index of the material to be tested is 1.3000-1.7000, the measurement by total reflection method has the advantages of convenient and rapid operation, low requirements for environmental conditions, and no need for monochromatic light sources. A refractometer is an instrument made by the total reflection method and specially used to measure the refractive index of transparent or translucent liquids. Using the Abbe refractometer to measure the refractive index of liquid to determine its composition is one of the commonly used analysis and detection methods in the production and scientific research of petrochemical, light industry and food.
Impact Factors and Controls
temperature
At different temperatures, the refractive index of the same medium is different, so the refractive index of different media must be compared at the same temperature. The refractive index of transparent materials is closely related to its temperature and composition. The refractive index of the solvent is usually determined at a temperature range of (5-30) °C. The refractometer should be placed at the corresponding temperature for two hours before it can be used for measurement.
Incident light wavelength
The influence of the medium on the propagation speed of different wavelengths of light is different, so the refractive index of the same medium measured by incident light of different wavelengths is different. The refractometer selects the D line 589.3mm of the sodium yellow light as the incident light through the Amish dispersion prism
Requirements for the refractive index of the substance to be measured
The range of refractive index of substances that can be measured by a refractometer is 1.30~1.70iii.
Relative humidity
Requirements for relative humidity: <85% 3 The standard working curve of the refractometer Firstly, at normal pressure and temperature of 30°C, use a refractometer to measure the refractive index of binary mixed solutions with different proportion concentrations, and determine the relationship between the molar composition of the solution and the refractive index , to obtain the standard curve of solution molar composition and refractive index at this temperature.
