Hypochlorite sensor based on Spectrophotometry

This paper investigates the production of an inline hypochlorite sensor for continuous measurement of hypochlorite strength based on spectrophotometry. This approach takes advantage of the advances in LED technology and its novelty lies in the wavelength of the chosen LED. Specifically, an LED at 395 nm (upper end of the UV range) is used where the absorption is lower, therefore allowing for measurements to be taken both accurately and costefficiently. An obtained correlation of 0.9878 between the known and measured hypochlorite concentrations confirmed that the Beer-Lambert law can be applied at this wavelength; and this demonstrated the validity of the assumptions underlying the idea of spectrophotometric measurement of the hypochlorite strength. The results also suggest that the same type of sensor could be used to develop a handheld device for the measurement of the commercial hypochlorite strength which is equally critical to the Water Companies.