Digital hypochlorous acid analyzer

Claim 1

An analyzer for continuously and accurately determining the hypochlorous acid content of chlorinated water containing free available chlorine having a hypochlorous acid component (HOCl) which is highly reactive, and a hypochlorite ion component (OC1 - ) which is a less reactive disinfectant, said analyzer comprising: first second and third probes to sense respectively the free available chlorine content (FAC), the pH factor and temperature in a sample of the chlorinated water to produce respective analog signals representative of these variables; means to convert said analog signals into corresponding digital input data; and a digital computer responsive to said input data to produce output data indicative of the HOCl content of the sample, said computer including a first memory storing the relationship existing at a reference temperature between the percentage of HOCl and OCl - in a predetermined range of pH values, and a second memory storing the relationship existing between temperature and the equilibrium constant of HOCl, means consulting the first memory and responsive to the input pH data to establish the percentage of HOCl in the sample, means consulting the second memory and responsive to the input T data to correct the established percentage of HOCl to produce a temperature-corrected HOCl percentage value, and means to multiply the temperature-corrected percentage value with the input FAC data to produce an output representing the HOCl content.