Usage of refractometer
1. Instrument installation: Place the Abbe refractometer in a bright place, but avoid direct sunlight to avoid rapid evaporation of the liquid sample due to heat. Use a super constant temperature bath to pass constant temperature water into the prism jacket and check if the reading of the thermometer on the prism meets the requirements.
2. Sample addition: Loosen the closing knobs of the measuring prism and the auxiliary prism, so that the frosted inclined surface of the auxiliary prism is in a horizontal position. If the surface of the prism is not clean, a small amount of acetone can be added dropwise, and the mirror surface can be lightly wiped in a single direction with wiping paper (not allowed to be wiped back and forth). After the mirror surface is washed and dried, use a dropper to add several drops of the sample onto the rough mirror surface of the auxiliary prism. Quickly close the auxiliary prism and tighten the closing knob. If the liquid is prone to volatilization, the action should be rapid, or the two prisms should be closed first, and then the sample should be injected through the liquid adding hole using a dropper.
3. Dimming: Rotate the lens barrel to make it vertical, adjust the reflector to allow incident light to enter the prism, and adjust the focal length of the eyepiece to make the cross hairs in the eyepiece clear and bright. Adjust the achromatic compensator to eliminate the colored light band in the eyepiece. Adjust the reading spiral again so that the light and dark interface coincides with the intersection of the cross hairs.
4. Reading: Read the refractive index value on the dial from the reading telescope. The commonly used Abbe refractometer can be read to the fourth digit after the Decimal separator. In order to make the reading accurate, the sample should be measured three times, each time the difference should not exceed 0.0002, and then the average value should be taken.
Abbe refractometer is an instrument that can measure the refractive index nD and average dispersion nF-Nc of transparent, semi transparent liquids or solids (mainly transparent liquids). If the instrument is connected to a thermostat, it can measure the refractive index nD at temperatures ranging from 0 ℃ to 70 ℃. Refractive index and average dispersion are one of the important optical constants of a substance, which can be used to understand its optical properties, purity, and dispersion size.
This instrument can measure the mass fraction (Brix) of sucrose solution (0-95%, equivalent to a refractive index of 1.333-1.531). Therefore, this instrument has a wide range of applications and is one of the indispensable and commonly used equipment in factories, schools, and scientific research institutions related to the petroleum industry, oil and fat industry, pharmaceutical industry, paint industry, daily chemical industry, sugar industry, and geological survey. Adopting visual aiming and optical dial reading, the operation is simple and easy to use. Measure the refractive index n average dispersion (n-n) of liquid or solid and the mass fraction of dry solids in sugar water solution, i.e. Brix. It can be used for testing and analysis in sugar making, pharmaceuticals, beverages, petroleum, food, chemical industry production, scientific research and teaching departments.
