Flame detectors and associated methods
AssigneeFFE Limited
InventorDaniel Waldron
Life of this patent
Estimating the term…
Abstract
A flame detector (1) including: a fire sensor (2a), capable of detecting a characteristic blackbody-type radiated heat signature emitted by a flaming material; and a guard sensor (2b), for detecting an at least further part of the spectrum emitted by the material and which serves to assist in rejecting false alarms, wherein, in use during detection of a flame, the guard sensor (2b) detects an amount of radiation G and the fire sensor (2a) detects an amount of radiation F, and positive detection of a flaming material depends upon the following criteria: F>0; G>0; and F>G.
Claims21
A flame detector comprising:
- a fire sensor, capable of detecting a characteristic blackbody-type radiated heat signature emitted by a flaming material, the fire sensor being configured to detect an intensity of radiation F in a fire band range of wavelengths;
- and
- a guard sensor, for detecting an at least further part of a spectrum emitted by said material and which serves to assist in rejecting false alarms, the guard sensor being configured to detect an intensity of radiation G in a guard band range of wavelengths,
- and the guard sensor being configured to detect radiation of shorter wavelength than the fire sensor,
- wherein the guard band range of wavelengths is narrower than the fire band range of wavelengths and each band range of wavelengths is distinct from the other, and positive detection of the flaming material depends upon the following criteria:
- F>0;
- G>0;
- and
- F>G.
A method for flame detection comprising:
- detecting an intensity of radiation F in a fire band range of wavelengths from a characteristic blackbody-type radiated heat signature emitted by a flaming material;
- and
- detecting an intensity of radiation G in a guard band range of wavelengths from an at least further part of a spectrum emitted by said material which serves in assisting rejection of false alarms,
- wherein, the guard band range of wavelengths are shorter than the fire band range of wavelengths, and the guard band range of wavelengths is narrower than the fire band range of wavelengths and each band range of wavelengths is distinct from the other, and
- detecting a flame if the following criteria are met:
- F>0;
- G>0;
- and
- F>G.
A flame detector comprising:
- a first sensor for detecting a characteristic blackbody-type radiated heat signature emitted by a flaming material, being configured to detect radiation is having a wavelength range of 1.6 μm to 2.4 μm;
- and
- a second sensor for detecting an at least further part of a spectrum emitted by said material and which serves to assist in rejecting false alarms, the second sensor being configured to detect radiation having a wavelength range of:
- from 0.6 μm to 1.4 μm,
- wherein each sensor comprises lead sulphide (PbS) or indium gallium arsenide (InGaAs).
Dependencies are inferred from the claim text.