Process for determining disturbances of a moisture cross profile of a fibrous material web in a paper making machine, a paper making machine, and a measuring arrangement for measuring the disturbances, the process including guiding the fibrous material web by way of at least one water-permeable belt and collecting and draining off water released from the belt. In one embodiment, a feeding tube includes an internal bolster, comprising one or more bolster arms that each include a first end hingedly connected to a distal end of the medical device and a free second end. The transmitted signals are then coupled to another chaotic system, the receiver system, so that the receiver and the transmitter are asymptotically synchronized.