Fiber Optical Micro-detectors for Oxygen Sensing in Power Plants

Technical Report · Sat Sep 30 04:00:00 EDT 2006

DOI:https://doi.org/10.2172/910438· OSTI ID:910438

Baker, Gregory L ^[1]; Ghosh, Ruby N; Osborn, D J; Zhang, Po

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1. Michigan State University

A reflection mode fiber optic oxygen sensor that can operate at high temperatures for power plant applications has been developed. The sensor is based on the {sup 3}O{sub 2} quenching of the red emission from hexanuclear molybdenum chloride clusters. We report on a fiber optic technique for detection of gas phase oxygen up to 100 C based on the {sup 3}O{sub 2} quenching of the luminescence from molybdenum chloride clusters, K{sub 2}Mo{sub 6}Cl{sub 14}. The inorganic sensing film is a composite of sol-gel particles embedded in a thin, oxygen permeable sol-gel binder. The particles are comprised of thermally stable, luminescent K{sub 2}Mo{sub 6}Cl{sub 14} clusters dispersed in a fully equilibrated sol-gel matrix. From 40 to 100 C, the fiber sensor switches {approx}6x in intensity in response to alternating pulses of <0.001% O2 and 21% O{sub 2} between two well defined levels with a response time of 10 s. The sensor signal is a few nW for an input pump power of 250 {micro}W. The normalized sensor signal is linear with molar oxygen concentration and fits the theoretical Stern-Volmer relationship. Although the sensitivity decreases with temperature, sensitivity at 100 C is 160 [O{sub 2}]{sup -1}. These parameters are well suited for in-situ, real-time monitoring of oxygen for industrial process control applications.

• Research Organization: Michigan State University
• Sponsoring Organization: USDOE
• DOE Contract Number: FC26-02NT41582
• OSTI ID: 910438
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
47 OTHER INSTRUMENTATION
DESIGN
FIBER OPTICS
LUMINESCENCE
MOLYBDENUM CHLORIDES
MONITORING
OXYGEN
POWER PLANTS
PROBES
PROCESS CONTROL
QUENCHING
REFLECTION
SENSITIVITY