A new photoelectric device for the measurement of yarn diameter and yarn evenness - Part III: Computer-aided on-line measurement of yarn evenness on the ring-spinning frame

A new on-line measurement system, Onlineven, based on photoelectric principles, is evaluated for measuring yam evenness, Descriptions of the sensor device used have been presented in Parts I and II of this series. Yarn specifications (linear density, twist) and measurement positions are the main topics discussed. Comparisons between Onlineven and the Uster Evenness Tester are also discussed. The results show that it is possible to use the Onlineven on-line-measurement system with yam-guide wheels for the measurement of the yarn evenness at various linear densities (12.9-29 tex) and twists (590-1396 turns/m) at position 2. The differences in yarn evenness between Onlineven and Uster Tester III are all less than 5%. The mean deviation of yarn evenness of this system is small and limited to +/-1%.