In situ chlorine detection by ultraviolet absorption spectroscopy

A low-cost spectrophotometric sensor with real-time data collection and digital signal processing (DSP) capabilities was constructed for the in situ measurement of aqueous chlorine. Using a parallel spectrophotometer composed of a xenon light source, a flow-through sample chamber, a spectrograph with a photodiode array detector, and a DSP, frequency-domain chlorine signatures were collected and processed. Data sets of varying concentration values were referenced to a commercially available colorimeter for evaluation of sensor performance and calculation of the optical parameters of aqueous hypochlorite.