Abstract: The invention uses microwaves in the spinning industry in order to determine the band mass of an elongated, substantially non-twisted fiber structure. In addition, a method for measuring the sliver mass from the frequency detuning and the damping of resonance signals of a microwave sensor while taking into consideration the moisture of the fiber structure with a computer is suggested. Likewise, a corresponding spinning preparation machine and a laboratory device for measuring the sliver mass are part of the invention. Lastly, a method and a spinning preparation machine for recognizing foreign matter in a moved fiber structure with the aid of microwaves is suggested.

Abstract: Different improvements of a spinning preparation machine are proposed to measure the fiber sliver thickness or the fiber sliver cross-section of at least one fiber sliver by means of one or several microwave sensors. One improvement is characterized by compressing means and special mechanical guiding elements that can be installed before, after and/or in the microwave sensor. It is also proposed to install a pair of conveyor rollers after a microwave sensor that can be designed in particular as an input roller pair of the subsequent drafting equipment. Furthermore, proposals are made for the calibration of the (at least one) microwave sensor.

Abstract: The invention concerns an apparatus for the optimization of the regulation adjustment of a machine in spinning preparation, in particular a regulated draw frame, a carding machine, or a combing machine, to which one or more fiber bands are continually fed. The apparatus has at least one sensor which is positioned ahead of the feed end of a draw frame machine for the purpose of capturing the values of band thicknesses of one or more of the entering fiber bands. The apparatus also has at least one delivery end sensor located at the delivery end of the draw frame machine for the purpose of capturing the values of the band thickness of the produced fiber band of a first draw frame operational mode. The apparatus also includes a microprocessor for the comparing of the captured values of the at least one delivery end sensor to those of at least a second draw frame operational mode, whereby the second draw frame operational mode does not represent the normal operational mode of the draw frame machine.