After measuring, use a lint-free tissue to wipe the sample off of the prism surface. If the sample contains oils or fat, use isopropyl alcohol and water to clean the prism surface.
• When not in use, keep the refractometer in the storage case at room temperature (20°C). Avoid storing the unit in direct sunlight or in a moist environment and do not subject the unit to strong shocks or vibrations. The ambient temperature at which you can safely store the units is between 0 and 40°C.