EVANESCENT FIELD FIBEROPTIC CHLORINE SENSOR

An evanescent field fibre-optic sensor for detecting chlorine in water is proposed and studied experimentally. The technique is based upon e vanescent field absorption through the colour development of reacting diethyl phenylene diamine with chlorine, which forms an azo compound. Sensor systems with single and multi-fibre sensing elements were desig ned, constructed and evaluated for linearity of response, sensitivity, and reproducibility of results. The experimental results establish th e feasibility of detecting low concentration chlorine in water using t he proposed method. The results for an improved design are indicative of reasonably good reproducibility and linearity of the sensor respons e.