Department of Applied Chemistry, School of Science and Technology, Meiji University, Kawasaki, Kanagawa, 214-8571, Japan.
Department of Environmental Biology and Chemistry, Graduate School of Science and Engineering for Research, University of Toyama, Toyama, 930-8555, Japan.
Anal Sci. 2022 Dec;38(12):1549-1554. doi: 10.1007/s44211-022-00189-1. Epub 2022 Sep 24.
Fiber optic sensors for monitoring scale deposition in geothermal brine and hot spring water should be safe, easily fabricated, and readily disposable. These desired features already have been enhanced in plastic optical fibers (POFs) and U-shaped sensors for other applications. The present work reports a U-shaped POF sensor for CaCO scale deposition. The sensors were easily fabricated by thermally bending the bulk POF without removing the cladding. At the bend, the percentage of total internal reflection between the water and the POF surface is affected by the high refractive index of the CaCO deposit. The optical responses of the U-shaped sensor to CaCO formation were investigated in a mixture of calcium chloride dehydrate and sodium hydrogen carbonate using a white-light source and a spectroscopic detector. The sensor was responsive to CaCO formation on the sensor surface and was especially sensitive at small bending radii. The sensitivity was further enhanced by increasing the number of bends. Finally, the U-shaped POF sensor was applied to the monitoring of CaCO scale deposition in hot spring water sampled at Matsushiro, Japan.
用于监测地热卤水和温泉水中结垢沉积的光纤传感器应该安全、易于制造且可轻易丢弃。这些理想特性已经在用于其他应用的塑料光纤 (POF) 和 U 型传感器中得到了增强。本工作报道了一种用于 CaCO 结垢沉积的 U 型 POF 传感器。传感器通过在不除去包层的情况下热弯曲块状 POF 来轻松制造。在弯曲处，水和 POF 表面之间的全内反射的百分比受到 CaCO 沉积物高折射率的影响。使用白光光源和分光探测器研究了 U 型传感器对碳酸钙形成的光学响应。传感器对传感器表面上碳酸钙的形成有响应，在小弯曲半径处特别敏感。通过增加弯曲次数进一步提高了灵敏度。最后，将 U 型 POF 传感器应用于监测日本松代采集的温泉水中的 CaCO 结垢沉积。
