High temperature optical fiber oxygen probe

Abstract

We report on the development of an optical sensor suitable for remote monitoring of oxygen in high temperature environments. The sensor is based on /sup 3/O/sub 2/ quenching of the red emission from hexanuclear molybdenum chloride clusters. A reflection mode fiber optic probe is being developed by immobilizing Mo/sub 6/Cl/sub 12/ in a porous sol-gel matrix at the far end of a high temperature silica fiber. The sensor signal as a function of temperature was determined from in-situ spectroscopic measurements, demonstrating operation up to at least 200/spl deg/C. One of the advantages of the inorganic Mo-cluster is the lack of sensitivity to gases typically present in a coal-fired boiler due to the triplet nature of the transition from the excited to ground state.