Fiber optic flame detection and temperature measurement system employing doped optical fiber
Patent 5051595 Issued on September 24, 1991. Estimated Expiration Date: 
December 6, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
December 6, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 2901740 3406389 3540041 3546689 3730259 3880324 Thermally activated electrochemical cell including an alkali metal salt solvate electrolyte High temperature sensor Fiber optical temperature measurement devices Fiber-optic temperature-measuring apparatus InventorsAssigneeApplicationNo. 446953 filed on 12/06/1989US Classes:250/458.1, LUMINOPHOR IRRADIATION250/227.14, Condition responsive light guide (e.g., light guide is physically affected by parameter sensed which results in light conveyed to the photocell)250/339.15, Sensing flame or explosion250/554, Flame light source340/578, By radiant energy374/161Change of optical propertyExaminersPrimary: Fields, Carolyn E.Assistant: Beyer, James Attorney, Agent or FirmInternational ClassesG01K 011/20G01J 001/58 AbstractA fiber optic fire detection and temperature measurement system 10 includes a fiber optic cable 12 having a lens 14 at a distal to direct radiation from a fire 16 into the cable 12 and to radiation detector 18 disposed at a proximal end of the cable 12. Detector 18 is coupled to a fire sensor 20. Detector 18 is sensitive to three wavelength bands including a short wavelength band of approximately 0.8 to 1.1 microns, a mid-wavelength band of approximately 1.3 to 1.5 microns and a long-wavelength band of approximately 1.8 to 2.1 microns. A controller 22, analyzes the fire sensor 20 output signals which correspond to the two spectral bands to determine if a fire is present. The fiber optic conductor is doped with a material selected for its temperature dependent fluorescent emission characteristics. Radiation from a fire passes via cable 12 to the detector 18. A pulse of radiation from source 28 passes from a coupler 26 and 26a to the cable 12. The fluorescent doping material within the fiber optic cable 12 is pumped by the pulse and is caused to fluoresce within the third wavelength band. A portion of the fluorescent emission passes back through the fiber 12 to the detector 18 where the fluorescent emission is detected and processed to determine the temperature.Other References
Field of SearchWith heating of luminophorsLight conductor Condition responsive light guide (e.g., light guide is physically affected by parameter sensed which results in light conveyed to the photocell) With detection of fiber microbend caused by parameter affecting fiber With spectral frequency/wavelength discrimination LUMINOPHOR IRRADIATION Methods With sample engaging rod or tube Flame By radiant energy Thermal By thermally emitted radiation With radiation conducting element Nonelectrical, nonmagnetic, or nonmechanical temperature responsive property Change of optical property | |
