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Fiber optic sensor for continuous monitoring of chlorinated solvents in the vadose zone and in groundwater: field test results

A fiber optic chemical sensor has been designed for groundwater and vadose zone monitoring of volatile halogenated hydrocarbons. The principle of detection is a quantitative, irreversible chemical reaction that forms visible light absorbing products. This absorption is measured remotely using fiber optics. Modifications of our previous sensor design have resulted in lower detection limits and increased durability. In this paper we describe the measurement system and present the new sensor design along with calibration data and preliminary field test results.