Division 4.1 Hydrometer

The specific gravity hydrometer is an instrument consisting of a glass float, which, at its lower end, is wide and heavy. There is a cylindrically shaped glass rod attached to the upper and of the float and coaxially orientated to it; the upper end of the rod is closed.

The glass float contains the load (lead, mercury, etc.) intended to adjust the hydrometer mass. The rod includes a graduated scale from 1,025 to 1,035 g/ml.

The hydrometer should he checked by the pycnometric method, using a pycnometer of a capacity of approximately 100 ml equipped with a precision thermometer.