Abstract:
A fire detector and method for generating an alarm signal in response to a fire uses an NDIR CO2 sensor to generate a detector signal based upon a 15μ absorption band of CO2 and generates an alarm signal when a signal processor receives the detector signal and a preselected criterion is met that is indicative of the onset of a fire based upon an analysis of the detector signal using a detection algorithm that relies upon a trending pattern of the detector signal such as recognizing a substantial drop in the detector signal strength. The NDIR CO2 sensor can also generate a reference detector signal based upon a 9.Oμ neutral band with a FWHM=0.5μ while the signal processor utilizes a detection algorithm that is based upon a synchronized output signal representative of CO2 concentration to generate an alarm signal when a preselected criterion indicative of the onset of a fire is met.
Abstract translation:用于响应于火而产生报警信号的火灾探测器和方法使用NDIR CO 2传感器来产生基于CO 2 2的15mu吸收带的检测器信号,以及 当信号处理器接收到检测器信号时,产生报警信号,并且根据检测器信号的分析,满足指示火灾开始的预选标准,使用检测算法,该检测算法依赖于检测器信号的趋势图案, 识别检测器信号强度的显着下降。 NDIR CO 2传感器还可以基于具有FWHM = 0.5mu的9.Omu中性频带生成参考检测器信号,同时信号处理器利用基于同步的输出信号代表的检测算法 的CO 2浓度,以在满足指示火灾开始的预选标准时产生报警信号。
Abstract:
A fire detector and method for generating an alarm signal in response to a fire uses an NDIR sensor to generate a detector signal based upon one or more absorption bands selected from the 15.1μ absorption band of CO2, the 6.27μ absorption band of H2O and the 4.67μ absorption band for CO and generates an alarm signal when a signal processor receives the detector signal and a preselected criterion is met that is indicative of the onset of a fire based upon an analysis of the detector signal using a detection algorithm that relies upon a trending pattern of the detector signal such as recognizing a substantial drop in the detector signal strength. The fire detector has a waveguide sample chamber (which can be of a re-entrant design) with at least one opening covered by a thin filtering membrane and a heat exchanger thermally connected to the sample chamber with at least one opening covered by another thin filtering membrane. If the NDIR sensor is to detect H2O molecules, the filtering membrane on the heat exchanger (which can be integrally formed out of aluminum with the sample chamber) allows H2O molecules to pass through it and inside surfaces of both the sample chamber and the heat exchanger are coated with a hydrophobic coating to prevent condensation of H2O molecules.
Abstract:
An infrared emitter, which utilizes a photonic bandgap (PBG) structure to produce electromagnetic emissions with a narrow band of wavelengths, includes a semiconductor material layer, a dielectric material layer overlaying the semiconductor material layer, and a metallic material layer having an inner side overlaying the dielectric material layer. The semiconductor material layer is capable of being coupled to an energy source for introducing energy to the semiconductor material layer. An array of holes are defined in the device in a periodic manner, wherein each hole extends at least partially through the metallic material layer. The three material layers are adapted to transfer energy from the semiconductor material layer to the outer side of the metallic material layer and emit electromagnetic energy in a narrow band of wavelengths from the outer side of the metallic material layer.
Abstract:
A blackbody radiation device (110) includes a planar filament emission element (102) and a planar detector (104) for respectively producing and detecting radiation having width dl/1 less than about 0.1 to test a sample gas, where 1 is the wavelength of the radiation; a reflector (108); a window (W); an electrical control (118); and a data output element (116).
Abstract:
A sensing apparatus consisting of more than one diode laser having select lasing frequencies, a multiplexer optically coupled to the outputs of the diode lasers with the multiplexer being further optically coupled to a pitch side optical fiber. Multiplexed laser light is transmitted through the pitch side optical fiber to a pitch optic operatively associated with a process chamber which may be a combustion chamber or the boiler of a coal or gas fired power plant. The pitch optic is oriented to project multiplexed laser output through the process chamber. Also operatively oriented with the process chamber is a catch optic in optical communication with the pitch optic to receive the multiplexed laser output projected through the process chamber. The catch optic is optically coupled to an optical fiber which transmits the multiplexed laser output to a demultiplexer. The demultiplexer demultiplexes the laser light and optically couples the select lasing frequencies of light to a detector with the detector being sensitive to one of the select lasing frequencies.
Abstract:
The invention relates to an infrared modulator for spectrometer. It comprises a light source (1), a beam splitter (2) for splitting the light from the source into two beams, a first plane mirror (4) for directing the light of the first beam, a second plane mirror (5) for directing the light of the second beam, a first cube corner mirror (7) for turning the light back to the first plane mirror (4), and a second cube corner mirror (6) for turning the light back to the second plane mirror (5). The first and second cube corner mirrors (6, 7) are arranged on a common optic axis to reflect into opposite directions and movable back and forth in the direction of said optic axis. According to the invention, the beam splitter (3) and the first and second plane mirrors (4, 5) are supported by the same support structure formed by one uniform material piece.
Abstract:
An apparatus for emulating various known night sky illumination conditions. The apparatus comprises a plurality of electrically-powerable LEDs which are disposed in an array and have respective spectral curves centered at different wavelengths in the visible to the short wave infrared wavebands, and means for fixing the temperatures of the LEDs to avoid temperature-induced changes in their spectral curves. Additionally, the apparatus includes means for varying the light intensities of the individual LEDs so that the combination of their spectral curves matches the spectrum of the known night sky illumination condition to be emulated, and means for regulating the total amount of light collected from the array so that the cumulative spectrum has the same intensity as the known night sky illumination condition to be emulated.
Abstract:
Novel systems and methods for remotely detecting at least one constituent of a gas via infrared detection are provided. A system includes at least one extended source of broadband infrared radiation and a spectrally sensitive receiver positioned remotely from the source. The source and the receiver are oriented such that a surface of the source is in the field of view of the receiver. The source includes a heating component thermally coupled to the surface, and the heating component is configured to heat the surface to a temperature above ambient temperature. The receiver is operable to collect spectral infrared absorption data representative of a gas present between the source and the receiver. The invention advantageously overcomes significant difficulties associated with active infrared detection techniques known in the art, and provides an infrared detection technique with a much greater sensitivity than passive infrared detection techniques known in the art.
Abstract:
A radiation source is presented that exhibits an improved efficiency of converting input energy into a quasi-blackbody output beam. A wavelength selective element can be included to transit one or more narrow bands of this radiation for use in spectroscopy. The intensity of the output beam can be varied quickly, thereby decreasing measurement times and enabling synchronous detection techniques to be implemented at reasonable frequencies. A feedback mechanism can be integrated into this device to enable accurate control of the blackbody temperature. This radiation source can be manufactured by conventional integrated circuit manufacturing techniques, thereby producing an inexpensive quasi-blackbody source of accurately and repeatably controlled performance.
Abstract:
A miniature source of modulated infra-red energy comprises a very thin heated wire strip (11) of low mass, mounted in a tensioned state by means of two resilient members (18), and a reflector (15) positioned behind the wire (11) so as to enhance the radiated energy. The source is hermetically sealed in an inert atmosphere with a cap (20). The cap (20) has an aperture (16) through which the energy emerges, this is sealed either with a window or a filter (17) if a specific wavelength is desired.