The measuring element is composed of a float and a conical glass tube.
A medium flows from the bottom to the top through the measuring ring, lifting the float until the buoyancy force and the weight of the float establish equilibrium.
The height of the float in the measuring ring is the measure of the flow. The flow rate is read directly from a scale inscribed on the glass.
The readings obtained apply solely to the medium for which the device has been calibrated or for a medium with the same density and viscosity