Weisbrich Martin, Messerer Dennis, Holzer Frank, Trommler Ulf, Roland Ulf, Holschemacher Klaus
Structural Concrete Institute, Leipzig University of Applied Sciences (HTWK Leipzig), 04275 Leipzig, Germany.
Department of Technical Biogeochemistry, Helmholtz Centre for Environmental Research (UFZ), 04318 Leipzig, Germany.
Sensors (Basel). 2024 Jul 18;24(14):4659. doi: 10.3390/s24144659.
The application of distributed fiber optic strain and temperature measurement can be utilized to address a multitude of measurement tasks across a diverse range of fields, particularly in the context of structural health monitoring in the domains of building construction, civil engineering, and special foundation engineering. However, a comprehensive understanding of the influences on the measurement method and the sensors is essential to prevent misinterpretations or measurement deviations. In this context, this study investigated the effects of moisture exposure, including various salt solutions and a high pH value, on a distributed strain measurement using Rayleigh backscattering. Three fiber optic sensors with different coating materials and one uncoated fiber were exposed to five different solutions for 24 h. The study revealed significant discrepancies (∼38%) in deformation between the three coating types depending on the surrounding solution. Furthermore, in contrast to the prevailing literature, which predominantly describes swelling effects, a negative deformation (∼-47 με) was observed in a magnesium chloride solution. The findings of this study indicate that corresponding effects can impact the precision of measurement, potentially leading to misinterpretations. Conversely, these effects could be used to conduct large-scale monitoring of chemical components using distributed fiber optic sensing.
分布式光纤应变和温度测量的应用可用于解决跨多个领域的众多测量任务，特别是在建筑施工、土木工程和特殊基础工程领域的结构健康监测方面。然而，全面了解对测量方法和传感器的影响对于防止误解或测量偏差至关重要。在此背景下，本研究调查了包括各种盐溶液和高pH值在内的湿气暴露对使用瑞利背散射的分布式应变测量的影响。将三个具有不同涂层材料的光纤传感器和一根未涂层光纤暴露于五种不同溶液中24小时。研究表明，根据周围溶液的不同，三种涂层类型之间的变形存在显著差异（约38%）。此外，与主要描述膨胀效应的现有文献相反，在氯化镁溶液中观察到负变形（约-47με）。本研究结果表明，相应的效应会影响测量精度，可能导致误解。相反，这些效应可用于使用分布式光纤传感对化学成分进行大规模监测。
