A novel probe for a fiber optic humidity sensor
A novel probe for a fiber optic humidity sensor
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DOI：
10.1016/s0925-4005(01)00899-1
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发表时间：
2001-11-20
影响因子：
8.4
通讯作者：
Ratnanjali
中科院分区：
文献类型：
--
作者：
Gupta, BD;Ratnanjali
报道了一种基于酚红掺杂聚甲基丙烯酸甲酯(PMMA)薄膜对塑料包层二氧化硅(PCS)光纤低折射率芯的一小部分光的湿度依赖吸收的光纤湿度传感器。薄膜的高折射率增加了光纤中引导的光与薄膜中的染料之间的相互作用，从而提高了传感器的灵敏度。为了将灵敏度提高许多倍，探头被设计成U形。U形探头减小了光线在弯曲区域的芯-膜界面处的入射角，从而增加了光从芯到膜的透射率。透射光的增加增加了它与存在于胶片中的染料的相互作用，从而提高了传感器的灵敏度。结果表明，随着探头弯曲半径的减小，传感器的灵敏度增加。该传感器工作在相对湿度为20%~80%的范围内，响应时间约为5 S，且具有较好的重现性。(C)2001 Elsevier Science B.V.保留所有权利。
A fiber optic humidity sensor based on the moisture dependence absorption of light by the phenol red doped polymethylmethacrylate (PMMA) film over a small portion of the lower refractive index core of the plastic clad silica (PCS) fiber is reported. The high refractive index of the film increases the interaction between the light guided in the fiber and the dye in the film and hence it increases the sensitivity of the sensor. To increase the sensitivity many fold the probe is designed as U-shaped. The U-shaped probe decreases the angle of incidence of the ray at the core-film interface in the bent region and hence increases the transmission of light from core to the film. The increase in the transmitted light increases its interaction with the dye present in the film and hence increases the sensitivity of the sensor. It has been shown that as the bending radius of the probe decreases the sensitivity of the sensor increases. The sensor operates in the humidity range 20 to 80% RH and its response time is about 5 s. Further a good degree of reproducibility of the results is obtained. (C) 2001 Elsevier Science B.V. All rights reserved.