THEORETICAL AND PRACTICAL RESPONSE EVALUATION OF A FIBER OPTIC SENSORFOR CHLORINATED HYDROCARBONS IN WATER

The response behavior of a polymer-coated mid-infrared fiber optical s ensor for chlorinated hydrocarbons in water is evaluated practically a nd theoretically. The sensor response to the target analytes tri- and tetrachloroethylene obtained in a muddy waste water sample is shown to be unaffected by other trace organic pollutants. A theoretical model is presented which can be used to predict the respone of this sensing device. The use of this model allows to simulate the sensor response n ot only for increasing chlorinated hydrocarbon concentrations, but rat her for any change in its concentration in the surrounding medium. In addition, the asymmetric sensor response, depending on the direction o f the concentration change and the lag time after a concentration chan ge can be explained by digital simulations and are shown to occur due to diffusion processes in the membrane.