| 摘要 |
This invention describes a method and a device for measuring the speed of delivery and the length of yarn produced in machines for forming and winding yarn. The yarn produced passes through a pair of capacity sensors which are placed at a predetermined distance apart. With the aid of oscillator circuits and phase lock loop, an electrical signal is formed corresponding to the capacitance of the sensor and consequently corresponding to the mass of yarn passing it. The lack of homogeneity in the mass of yarn is detected successively by the two sensors. The aforementioned signal is digitised and fed to a digital signal heterocorrelator which calculates the time difference. With data on the distance between the capacity sensors, the speed of delivery of the yarn can be calculated and thus the total length of yarn passing. |
