EuroWire November 2021

Technical Article

Visualisation of the measuring data The tension gauge head is available with all common interfaces and industrial field buses, such as Profinet IO, Ethernet/IP or Profibus- DP. Therefore, digital or analogue data transmission is available depending on the requirements of the customer. Additionally, the gauge head can be connected to a processor system that is also available. The processor system provides further interfaces such as OPC UA, and visualises the production data. It is possible to display single measurement values, for example, for the analysis and optimisation of processes. Furthermore, the measuring values of the tension gauge head can be merged with values of other measuring devices, such as diameter measurement values. Due to the combined evaluation, the so-called sensor fusion, plausibility and significance of the recorded data are increased and the quality of the measuring results is further improved. In addition to the stand-alone device for tension measurement, Sikora offers systems for the measurement of the diameter and the position of the uncoated and coated fibre, which also determine the tension via vibration measuring method. Further gauge heads measure and control in combination with a processor system the temperature of the optical fibre at the hot and the cold position of the drawing process. Gauge heads for the detection of airlines, for the measurement of the concentricity of the coating and for the detection of lumps, neckdowns and blisters on the surface of the coated fibre complement Sikora’s portfolio for the quality control of optical fibre. Conclusion In order to establish a sustainable infrastructure sufficient for the needs and requirements of our ever-increasing digital society, the quality of the optical fibres used and thus the optical fibre cable is crucial. The measurement and control of the tension in the drawing process has a direct and significant impact on the product quality. The stand-alonegauge headdevelopedby Sikora uses a technology that applies the birefringence principle with a measuring rate of up to 10 kHz. This enables a faster and highly precise tension measurement that is independent of outer production influences and allows for immediate control of the tension. Necessary specifications are fulfilled and the high grade of the fibre is guaranteed. Therefore, the system contributes significantly to highest and reproducible quality. Additionally, it lays the foundation for an efficient and future-oriented production. n Further available measuring and control technology for comprehensive quality control

Figure 2 : The stand-alone gauge head measures the tension of optical fibres in the drawing tower

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A light source sends polarised light that travels through the optical fibre. Due to the direction-dependent refraction index, a change of the original polarisation occurs. The exiting double refracted light is received by a detection unit. This determines the difference of the polarisation of the received light to the original polarisation of the light source. This difference is seen as the measure for the tension exerted on the optical fibre ( Figure 1 ). The self-sufficient stand-alone measuring system offers a more resilient and precise tension measurement for validation and faster control of this important parameter. This is achieved by the innovative measuring principle and the measuring rate of up to 10 kHz. The measuring area of the system is up to 400g and the reproducibility amounts to ±0.1g. The gauge head can be installed either before or after the cold position of the uncoated fibre. The measured value is independent of production influences such as the position of the fibre in the measuring field, the production line speed and the vibration or oscillation of the fibre. Therefore, the gauge head can also be used for statistical offline measurements if needed. For example, the calibration of the system can be checked easily by using test probes. The system generates reliable and stable measuring values and thus enables immediate control of the tension. The installation in existing drawing towers is possible at any time. The application of the described stand-alone gauge heads is particularly attractive for manufacturers who want to receive high quality due to an optimal production process with minimal scrap and at smallest possible resource usage. Use of the systems and application area

Sikora AG Bruchweide 2, 28307 Bremen Germany

Tel: +49 421 48900 0 Fax: +49 421 48900 90

sales@sikora.net www.sikora.net

▲ Figure 3 : In addition to the tension, the available processor system visualises measuring values of further Sikora gauge heads in the drawing tower

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November 2021