A Prism Based Optical Fiber System for Liquid Sensing

Operation of a prism optical fiber sensor for liquid level detection is described. This sensor operates on light intensity modulation, where modulations result from alteration of total internal reflection into partial reflection at the interface. The modulated intensity has been measured by using a source light, a pair of plastic optical fibers (one transmitting and the second one acting as receiving fiber) and a glass prism providing the total and partial reflections. The performance of this sensor is tested with a laser source and the results are reported here. To ana- lyze the operation of such a sensor theoretical formulation for the sensor operation is also given in this study. A comparison is made between the theoretical estimation and the experimental results.