OIML Recommendation R 124:1997

Refractometers for the measurement of the sugar content of grape musts

Scope: The refractometers which are the subject of this Recommendation are instruments which measure the refractive index of grape must before fermentation, using the phenomenon of light refraction or of total internal reflection of light. The result of measurement is given in one of the forms indicated in section III of the Recommendation. These instruments may also be used to measure the refractive index of sugar solutions and, possibly, of concentrated must.