The setting of the distance between the drum and the flat is crucial for carding quality of fiber, e.g. wool. Investigations have shown that manual gap settings with the gage to the left and right on the carding machine are not equal and that with the machine at standstill slight deviations from the operating conditions arise. The remedy is provided
by a measuring flat rod (FCT) with two or three capacitive sensors which is exchanged for a flat rod. The sensors measure the distance to the drum via the drum width. The other distance signals are passed to the PC. The fully automatic measurement sequence eliminates erroneous settings and shortens the setup time. The inspection and documentation of the results facilitates practical quality assurance.