You would like to monitor the quality of glasses and polymers that are used in lens production? – The refractometer by SCHMIDT+HAENSCH will help you to surveil glass and polymer production and performs raw material control. The dimensionless parameter named after German physicist Ernst Abbe is also known as the V-number or constringence of a transparent material. It indicates material dispersion and shows how much the refractive index changes with the wavelength of the light. The higher the dispersion, the smaller the Abbe number. The number is given by a function of the refractive indices of a material at 486.1 nm, 587.6 nm and 656.3 nm.