Abstract

Numerous fiber optic pH sensors have been proposed in the past decade. Most of these sensors utilize polymers as a substrate to immobilize optically active organic indicators^1,2. However, these devices often exhibit significant degradation in the presence of organic solvents and are less stable at high temperatures or pressures typically encountered in many industrial and practical applications. Recently, the use of inorganic materials as the substrates for the immobilization of indicators has obtained more attention^3,4. This report describes the development of a new fiber optic pH sensor based on the use of a porous silica glass fiber immobilized with pH indicators by sol-gel coating technique.

© 1992 Optical Society of America