Title :
High Temperature Oxygen Sensing Using K2Mo6Cl14 Luminescence
Author :
Zhang, Po ; Osborn, D.J. ; Baker, Gregory L. ; Ghosh, Ruby N.
Author_Institution :
Dept. of Phys. & Astron., Michigan State Univ., East Lansing, MI
fDate :
Oct. 30 2005-Nov. 3 2005
Abstract :
A reflection mode optical sensing system for monitoring oxygen in high temperature gas flows, 25-220degC and 500 sccm, is presented. The sensor is based on 3O2 quenching of the red emission from K2Mo6Cl14, one member of a family of hexanuclear molybdenum chloride clusters. One advantage of using inorganic Mo-clusters as the lumophore 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. The sensor is prepared by dip-coating fiber tip in a sol-gel solution containing K2Mo6Cl14 particle clusters. Drying and aging yields a composite film with K2Mo6Cl14 immobilized in a porous silica matrix. The composite film deposited on a planar substrate was characterized via in-situ spectroscopic measurement up to 200degC. The emission intensity is constant following 56 cumulative hours of heating at 200degC, demonstrating long-term stability at high temperature
Keywords :
fibre optic sensors; gas sensors; high-temperature techniques; luminescence; molybdenum compounds; oxygen; potassium compounds; sol-gel processing; temperature sensors; 25 to 220 C; K2Mo6Cl14; aging; coal-fired boiler; composite film; dip-coating; emission intensity; hexanuclear molybdenum chloride clusters; high temperature gas flows; high temperature oxygen sensing; in-situ spectroscopic measurement; inorganic Mo-clusters; luminescence; lumophore; oxygen monitoring; oxygen quenching; porous silica matrix; red emission; reflection mode optical sensing system; sol-gel solution; Boilers; Fluid flow; Gases; Luminescence; Monitoring; Optical reflection; Optical sensors; Oxygen; Stationary state; Temperature sensors;
Conference_Titel :
Sensors, 2005 IEEE
Conference_Location :
Irvine, CA
Print_ISBN :
0-7803-9056-3
DOI :
10.1109/ICSENS.2005.1597777