Apparatus to test the stretch behavior of yarns has a measurement head to generate measurement signals to be evaluated by spectral analysis to show deviations in the signal with a display for the findings

摘要

To test a yarn (14), by applying a pull force as it moves through the test appts., a signal is generated which represent the yarn behavior while under a draw tension. The deviations in the signal are evaluated by spectral analysis. The spectral analysis unit (40) has a display (46) to show the findings of the analysis. The measurement head (20), which generates the measurement signal, swings as a function of a parameter of the moving yarn (14), and it generates an analog signal. If required, the signal is passed through an analog/digital converter (42) to give a digital signal for processing (44). The findings of the analysis are displayed on a screen (46) and/or a printer or plotter (48). The appts. applies a sufficient force to stretch the yarn (14) by a given value, for the required draw force to be applied again to the start signal. The appts. gives a continuous spectral analysis, and can compare measured values on a time shift to give comparisons which are evaluated by spectral analysis.