The hydrometer makes it possible to determine the density of a liquid in which it is immersed according to Archimedes' principle. It is composed of a cylindrical hull acting as a float and a graduated rod. The reading is taken at the top of the meniscus at 20°C. There are several models of hydrometers (with or without thermometers) that cover a range from 1.015 to 1.035 and subdivisions of 0.0005, 0.0002 and 0.0001. Our density hydrometers for milk are produced according to applicable standards.