Fiber optic pH sensor having low drift rate

摘要

A hydrolyzed dye/gel polymer for use in a pH-based sensor is characterized by its chemical and optical stability with respect to dye loss with time. Preferably, the dye/gel polymer is hydrolyzed by heating in a dilute base solution for a period of time sufficient to remove weakly bonded dye molecules from the polymer, then washed to remove the base solution and loose dye.