Performance study of optical sensor for parameterization of staple yarn

This work deals with the development of a low cost high resolution yarn characterization unit with optical sensor. The developed system can measure yarn average diameter, diameter variation over length, variation of yarn mass, yarn faults, number of hairs at specific distances from yarn core, mean absolute deviation and coefficient of variation in a single run. The most lucrative feature of the newly developed instrument is one hundredth times lower cost and 8 times higher resolution than the existing one. The sensor signal is fed to a high speed data acquisition system and custom made software to get yarn parameters when the yarn is passed in front of the sensor by mechanical setup. The output of the system is compared with the output of the widely used Tester for the said purpose. Moreover, unlike the standard tester, the newly developed instrument is able to furnish absolute mass and diameter of the yarn in real unit. These important parameters certainly give two important estimates for judging the final look of the fabric. The repeatability of results is insignificant in 0.5% level. Calibration is done by taking a standard wire. Jute and cotton yarns of different tex values are tested with the instrument and results are reported. FFT is also performed to provide equivalent frequency response of diameter/mass profile. It seems to be more significant representation of the parameters under consideration.