Inside the flow tube, there is a star guided float which works towards a spring. An annular gap is produced between the cone-shaped magnet system and the meter ring in case of flows other than zero. The position of the magnet system de-pends on the resulting force of all forces acting upon it. These forces comprise the flow force, a spring force acting opposite to the flow force, and the buoyancy and weight force signifi-cant for the measurements in case of vertical installation. Each position of the magnet holder corresponds to a flow value measured during calibration, which is transferred to a scale.
The BGF flow meter consists of a meter tube with connecti-ons, a meter ring, and a conical magnet holder. By means of a magnet, the position of the magnet system is transferred to an encapsulated follow magnet, which has been fitted to a pointer axle. The position of a second annular follow magnet fitted on the pointer axle is transferred to the scale by means of the pointer.