Abstract
In this practical session, the aim is to measure the refractive indices and concentrations of sugar solutions using an Abbe refractometer.
Extract
[...] This indicates that the measurements made using the refractometer show a slight deviation in average. The relative error is particularly high in Solution 1 (14.3 and just within the limits of the permissible relative error in Solution 4. Possible sources of error can be for example: - Temperature variations during the experiment: the Table 2 provided shows that the value of the refraction index varies with temperature, - Misreading in the refractometer, - Incomplete sample preparation or cleaning. The relative error of the concentrations of solutions and 5 show zero values. [...]
[...] Adjust it to the center of the light field defined by the diagonals. Focus the light interface with the smaller screw (micro-screw) on the right side of the refractometer. Read the corresponding concentration (top scale) and refractive index (lower scale). 4. Write both values in a table (see Results in Table 1 below) 5. Repeat this procedure for all the attached sucrose solutions of unknown concentration. 6. In case the actual temperature is different from 20°C, correct measured data of concentration to an actual temperature using the attached table of corrections. [...]
[...] Biophysics: refractometry Task: Measure refractive indexes and concentrations of the sugar solutions using an Abbe refractometer. Protocol: Principle of refractometry: Refractometry is a technique used to determine the Refractive index of a liquid sample by measuring how light propagates through that medium. The Refractive index depends on the concentration of the solutions in particular. In this experiment we will measure it to determine the unknown concentrations of different sucrose solutions. Materials / Apparatus: - Abbe refractometer - sucrose solutions - ethanol - Pasteur pipette - paper swabs - correction table (Table 2). [...]
