Mechanical flow meters

The rotámetro determines the flow of a fluid, this is, liquid or gas in a pipe. A body in suspension is lifted by the inertia of the fluid itself inside a tube. The height reached by the body suspended is proportional to the circulating flow. If the flow rate increases, the flow resistance increases so the floater rotatometro raises increasing the surface between the suspension and the glass tube. With this, the flow resistance decreases until it is equal to the sum of the force of the weight of the body in suspension. The tube where the floater is (made [...]

It is based on the movement caused by fluid flow over a disk situated in the circulation zone. This movement has a direct relation with the speed of the fluid. The movement of the disk is mechanically transmitted to a needle that moves through a graduated scale indicating the flow.