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Electro-Optical Fire Detection “A History”. “World Leader in Electro-Optical Flame Detection Technology”. Electro-Optical Fire Detectors. Used in many Industries: Oil & Gas Exploration and Production Gas Transmission Automotive Semiconductor Aviation All Types of Manufacturing.
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Electro-Optical Fire Detection “A History” “World Leader in Electro-Optical Flame Detection Technology”
Electro-Optical Fire Detectors Used in many Industries: • Oil & Gas Exploration and Production • Gas Transmission • Automotive • Semiconductor • Aviation • All Types of Manufacturing
Electro-Optical Fire Detectors Fires are detected by: • Smell • Sound • Sight • Heat
Electro-Optical Fire Detectors Different types of Fire Detection are: • Smoke Detectors • Heat Detectors • Fusible Links • Manual Call Points • Linear Heat Detectors • Electro-Optical Fire Detectors
Electro-Optical Fire Detectors A Typical Fire requires: • Source of Ignition • Fuel • Oxygen or an oxidant
Electro-Optical Fire Detectors Hydrocarbon Fires produce: Water and Carbon Dioxide Heat, (radiant infrared energy) Typical combustion of a hydrocarbon C3H8 + 5O2 = 3CO2 + 4H2O (propane + oxygen = carbon dioxide + water) Incomplete combustion produces more Carbon Monoxide (CO)
Electro-Optical Fire Detectors Advantages of Electro-Optical Fire Detectors: • Fast - detects fire in the early stages • Area Coverage, not a point detector. Does not have to be located directly at the fire event • Detects electro-optical radiant energy from the fire, (moves at the Speed of Light)
Electro-Optical Fire Detectors Electro-Optical Energy includes: • Infrared (IR) radiant energy • Ultraviolet (UV) energy • Visible Light (VIS) Modern Electro-Optical Fire Detectors use all or a combination of these three light spectra to detect a fire
Early Electro-Optical IR Fire Detectors Early Fire Detectors use IR sensors developed during WWII • Designed to respond to near IR • Some discrimination by using “flicker” amplifiers • Could be fooled by non-fire events such as shimmering water, vibrating manifolds, etc.
Early Electro-Optical UV Fire Detectors Alternative technology using UV Tubes: • Fast response • Solar blind • Could be fooled by non-fire events emitting short band UV energy, such as lightning, quartz halogen lights and arc welding • Prone to physical damage due to tube design • Expensive to maintain
Early Electro-Optical UV/IR Fire Detectors • UV Tubes combined with Narrow Band IR sensors: • IR sensors use Narrow Band Interference filters at 4.3 microns (CO2 “Spike”) • Some discrimination by using “flicker” amplifiers • Attempted to reduce alarms to non-fire events by using “AND” gates
Early Electro-Optical UV/IR Fire Detectors Disadvantages: • Will only respond to hydrocarbon fires • CO2 “spike” is unpredictable • Real world fires have incomplete combustion, producing more CO, less CO2 • Narrow Band IR sensor detects less than 1% of radiant IR energy from the fire • Old Analog technology
Modern Electro-OpticalMulti-Spectrum Fire Detectors • Developed from Military Missile Warning Systems • Multi-sensor array using UV/WIR & VIS • Solid state, digital electronics • Real time, digital signal processing • Fire Event data storage for postulating the cause of a fire • Responds to all types of fires
Modern Electro-OpticalMulti-Spectrum Fire Detectors Modern UV Tubes have: • Long glass to metal seal to prevent leakage and damage from vibration • Machine-made to ensure constant high quality • Anode & Cathode made from steel to prevent vibration
Modern Electro-OpticalMulti-Spectrum Fire Detectors Wide Band Infrared (WIR) sensors: • Respond to IR between 0.7 & 3.5 microns and detect over 88% of a fire’s radiant energy • Sees all types of fires • Does not use optical interference filters • Fast acting “Quantum” effect sensor, same as used in military applications • Easier to detect a small fire & track it as it grows and/or gets hotter
Modern Electro-OpticalMulti-Spectrum Fire Detectors Blackbody Curve for a 2500K degree fire showing Wide Band IR Coveragecompared to the Narrow Band Spike at 4.3 microns
Modern Electro-OpticalMulti-Spectrum Fire Detectors Percentage of Total Radiant Energy - Wide Band v. Narrow Band
Modern Electro-OpticalMulti-Spectrum Fire Detectors Additional Features: • Visible Sensors, (Blue & Yellow), reject non-fire radiant energy events such as lightning, quartz halogen lights and arc-welding • Temperature Transducer and programmable software provide stable WIR sensor sensitivity baseline
Modern Electro-OpticalMulti-Spectrum Fire Detectors Solid State Digital Design • Digital signal processing of Real Time data by sophisticated software algorithms • Fire Event spectral data stored in non-volatile memory • Real Time data available through PC software • Digital communications allows for addressable, smart devices
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