The refractive index of a solution can be measured manually or digitally. Manual methods like a portable optical refractometer or an ABBE optical refractometer are widely used for the determination of refractive index and related values, e.g. BRIX°, alcohol %, Baumé, Plato, etc. Although these methods are easy to use and quite inexpensive, they require expertise in every step of the manual operation protocols, which often affects the accuracy and reliability of the results. Digital refractometers / brix meters are available as benchtop and handheld instruments. They measure liquid samples digitally, reducing operator influence considerably.

Compare digital refractometers with manual methods: View the different measuring techniques