Intensity Modulated U-Shaped Bent Tapered Optical Fiber Concentration Sensor

• Published in: Electronic Systems and Intelligent Computing Vol. 686; pp. 957 - 964
• Main Authors: Kishore, Putha, Dinakar, D., Padmavathi, Manchineellu, Obulapathi, L.
• Format: Book Chapter
• Language: English
• Published: Singapore Springer Singapore Pte. Limited 2020; Springer Singapore
• Series: Lecture Notes in Electrical Engineering
• Subjects: Concentration; Hysteresis area; Intensity modulated; Plastic optical fiber; U-shaped bend; Viscosity
• ISBN: 9811570302; 9789811570308
• ISSN: 1876-1100; 1876-1119
• DOI: 10.1007/978-981-15-7031-5_91

In this paper, a liquid concentration (viscosity) sensor is designed and developed at a low cost using a clad removed U-shaped bent plastic optical fiber (POF). A small portion of POF cladding is removed and bends to form a U-shaped probe for an optimized radius to improve the sensitivity of parameter measurement. The probe is immersed in a viscous liquid, then the interaction of the evanescent field with the ambient viscous liquid in both forward and reverse directions movements of the liquid were recorded. As the probe dipped slowly in and out of the liquid an offset is observed in the response of the sensor, it can be measured as the hysteresis loss in the loop. The offset has been measured in both horizontal (Distance) and vertical (Intensity) directions. The experimental results reveal that the sensor is highly linear with about 0.98 linearities. From the results, It is observed that intensity offset measurement is more suitable than distance offset owing to high sensitivity. Thus, the concentration (or viscosity) of the liquid can be measured using the proposed simple sensor in terms of the offset height and hysteresis area. This sensor is easy to make, simple, low cost, and had inherent advantages of the optical fiber like Immune to EMI, corrosive, small size, flexibility in length. The sensor may found many applications in measuring the viscosities of fluids such as motor oils, petroleum products, chemical solvents, and many other industrial and biological fluids.