Compensated SAW Yarn Tension Sensor

The measurement and control of yarn tension is important in textile technology. This paper presents a two channel architecture surface acoustic wave yarn tension sensor, which is able to provide a sensitivity about two times bigger than the previous one. The design and the fabrication of the devices are also presented. A mathematical analysis shows that the output frequency of the sensor varies linearly with the yarn tension. To test the performance of the sensor, an experiment is carried out to obtain the output frequencies in different yarn tension. The results show that the sensor has a sensitivity of 8234 Hz/N (80.75 Hz/gf), and the sensor is capable of measuring a range of 0-0.196 N (20 gf) yarn tension with a relative error of 2% and a hysteresis error of 3%.