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Hazard Detection Equipment

Critical

Life

Safety

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Flame Detectors - Past

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Flame Detectors - Present

X2200 UVX3301 MSIR

X3302 MSIR(H2)

X5200 UVIR

X9800 IR

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Flame Detection - The Reasons

• Actual loss/catastrophe

• Fire department/AHJ requirement

• Code requirement

• Recognition of risk/preventative measure

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Flame Detection - The Means

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The Basis of Optical Flame Detection

Radiant + Thermal Energy

CH4 + 2 O2 2 H2O + CO2 +

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Electro-Magnetic Spectrum

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Gasoline Flame Spectral Signature

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Optical Flame Detection - Advantages

• Rapid detection capability

• Detects from a distance

• Highly resistant to environmental conditions (wind, cold, rain)

• Self-check capability

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Optical Flame Detection - Limitations

• Useless on smoldering fires

• Requires “line of sight”

• Technically sophisticated

• Higher Cost

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The Customer Expectation

• Detect Fire

• Only Fire

• Anytime there is fire

• Anywhere there is fire

• Or annunciate a fault condition

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Optical Flame Detection - The Strategy

• Utilize features of flame emissions

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Consecutive gates

UV Spectral Selection to Minimize Interference

Terrestrial SolarSpectrum

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Consecutive gates

IR Spectral SelectionPick a Bright Spot

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Consecutive gates

IR Spectral SelectionMinimize Solar Interference

Mid-IRFlame Emission

Band

Terrestrial SolarSpectrum

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Consecutive gates

IR Spectral SelectionMinimize Solar Interference

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Optical Flame DetectionThe Methods

• UV Detection

• IR Detection

• UV/IR Detection

• Multi-IR Detection

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Optical Flame DetectionThe False Alarm Challenges

• UV - emitted by nearly all fires but... electrical discharge arc-welding, lightning, motors are also strong UV emitters.

• IR - fire has strong emissions but… so do hot objects.

• UVIR - improved false alarm resistance but… it is vulnerable to combinations.

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Consecutive gates

Blackbody IR Emissions

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• Fire “flickers” randomly. • Non-flame IR

– Tends to be static or– “flickers” with a regular period.

No Fire Alarm

Fire Alarm!

Advanced TechnologyIR Temporal Features

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Consecutive gates

Advanced TechnologyUV Temporal Features

• Fire produces continuous UV

• Many electrical discharges are momentary

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Consecutive gates

Multi-IR Method

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• Multi-IR - excellent false alarm resistance and flame detection but.. it is complex & hard to do well.– Fuels vary in IR emissions– Black body sources desensitize– IR filter band-pass “blue-shifts” off-axis

Multi-IR Flame DetectionThe Challenges

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Fuel Type Emissions

0

0.2

0.4

0.6

0.8

1

1.2

3 3.25 3.5 3.75 4 4.25 4.5 4.75 5

Wavelength (microns)

Inte

nsi

ty

Gasoline

Methane

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CO2 Emission Peak

• Patented wavelength criteria

Wavelength X3301

4 microns 5 microns

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From The Detectors Point Of View

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How Flame Detectors See the World

• Conically-shaped area extending

from detector optics

• Center axis provides highest

sensitivity

• Detection range depends on

detector & fuel type

• Optimum protection leaves no

gaps in COV layout

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Consecutive gates

MIR ChallengesFilter “Blueshift”

REF A

REF A

REF A

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Interference Desensitization

0

0.2

0.4

0.6

0.8

1

1.2

1.4

Ref AFlameRef B

FLAME SUN FLAME + SUN