Ideally, the center of gravity of a filled tank should not be any higher than the bearing points of the tank – a feature that is frequently not implemented.
For reasons of stability, it is advantageous for the center of gravity to be lower than the bearing points. The position of the center of gravity as a function of the filling level has a considerable effect on the number of load cells that are used. If the filling is arranged symmetrically to the load cells, it may be possible to set up a weighing device with one load cell, given that the position of the center of gravity moves along a vertical line (see also 6.3). If the center of gravity also moves to the side as the mass of filling changes, all the supports must be equipped with load cells. Rocker and fixed bearings should never be considered for applications of this type!
Figure 2 illustrates the necessity of using load cells on all bearing points if the position of the center of gravity changes.