A floating measuring body is raised by the flow rate in a conical measuring pipe until a balance is reached between the weight of the floating body and the flow resistance (Figure S 39). This means that the floating body is raised higher as the flow rate increases (a). According to this float principle, devices can only be installed perpendicular and are primarily used in pneumatic systems.
Loading a floating body with a spring force means that the measuring device is position-independent and can be designed such that it also works independently of the viscosity (b). Devices of this nature are manufactured for pressures up to 400 bar and for use in hydraulic systems,.
Figure S 39: Float principle