Fiber optic sensor for the detection of ammonia, phosphate and iron in water

Abstract

We report the design, development, and analysis of an evanescent wave fiber optic sensor, for detecting different chemical contaminants in water. The sensors are made up of a step index plastic multimode fiber. Different chemical contaminants in water like iron, phosphate and ammonia are determined using this sensor. The proposed measuring system with LED source is inexpensive and easily portable. The errors in measurement due to turbidity and other interferences are eliminated with the dual wavelength probing. Hence the proposed sensing method enhances sensitivity, selectivity and repeatability of measurement.