Refractometers are instruments used for measuring concentrations of aqueous solutions. A refractometer requires only a few drops of liquid. When light enters the liquid, the light changes directions. This is called a refraction. A refractometer measures the degree to which the light changes direction, called the angle of refraction. A refractometer takes the refraction angles and correlates them to refractive index (nD) values that have been established. Using these values, you can determine the concentrations of solutions. Choose from our large selection of handheld and benchtop refractometers. Ideal for use in the food, agricultural, chemical, and manufacturing industries.