Abstract: There is disclosed a method and an apparatus for monitoring textile yarn quality. Textile yarn is checked for quality to meet the required criteria such as diameter evenness and unwanted foreign fiber presence by utilizing an artificial diffuse light illuminating image sensor, with the yarn placed as an obstacle, into the pathway of the light, the contours of the light being focused for sharp image capture. The yarn diameter is determined by processing of focused yarn image.

Abstract: The invention relates to a method and apparatus for monitoring yarn quality in the textile industry. Textile yarn is checked for quality to meet the required criteria such as diameter evenness and unwanted foreign fiber presence. The invention utilizes an artificial light illuminating the yarn, focusing element, diffraction element and the image sensor for capturing of focused diffracted rays from illuminated yarn image. The presence of foreign fibres in yarn and yarn diameter is determined by processing of captured image.