when the branching device 17 is in its straight thru condition or position or to a quantity measuring device 19 e g a balance when the branching device 17 is in a 34 diverting 34 condition or position the arrangement comprising the elements 17 18 and 19 is used for measuring the fibre quantities supplied by the fibre metering units 11 and is shown in greater detail again in fig2 in the example shown a pneumatic fibre transport via ducts is assumed to be used the fibre ducts designed as tubes 25 and 26 lead from the second branching device 17 to the quantity measuring device 19 and to the receiver or recipient 18 respectively the quantity measuring device 19 is designed as a balance in such a manner that the fibres supplied to it can be weighed using a weighing device 27 an evaluating device 30 is connected via an electric connection 29 with the weighing device 27 it is provided with a keyboard 31 for information input values an information or data output point 32 and a display 33 for keeping the cards 16 operating without interruption the storage device 15 at all times must contain fibre material in order to ensure this somewhat more material is supplied to it during the supply times than is used by the cards 16 the storage device 15 is provided with a signal device 20 which transmits a signal if the minimum and the maximum filling level of the storage device 15 is reached control of the filling level can e g be effected by photocell.