Method for measuring chemical levels using pH shift

摘要

A method of measuring the free chlorine level in a solution of chlorinated pool/spa water comprises a first sample of said solution having a first selected pH and a second sample of said solution having a second selected pH and determining first and second ultraviolet light (UV) transmissivity values for each of the first and second samples. The first and second transmissivity values are then used to determine the free chlorine level.