| 摘要 |
The invention relates to a method and a device for identifying foreign bodies in a base textile material (1, 3, 5). Said base textile material is subjected to beams (35, 36), and the beams (44) reflected on the base material are detected and converted into an electrical signal. In order to detect foreign bodies in the material in a targeted manner and to differentiate them from each other, in such a way that all or only the unwanted foreign bodies can be, for example, eliminated, the beams (35, 36) emitted essentially comprise two defined and differing wavelength ranges (lambd1 and lambd2) and the reflected beams are simultaneously and commonly detected from the two wavelength ranges. Preferably, a first defined wavelength range can be selected in such a way that the beams reflected on the base material provide any values in the electrical signal, for at least two different foreign bodies, and another defined wavelength range for the beams is selected in such a way that the reflected beams provide electrical signals for the two foreign bodies, in a different ratio to the first wavelength range. The device comprises a radiation source (19) for emitting beams (35, 36) in at least two wavelength ranges, and a receiver (20) for measuring the beams which are fully reflected on the material. |
