公开(公告)号：US4500207A

公开(公告)日：1985-02-19

申请号：US440040

申请日：1982-11-08

申请人： Adrian J. Maiden

发明人： Adrian J. Maiden

IPC分类号： G01N21/35 ,  G01N21/61

CPC分类号： G01N21/3518 ,  G01N21/3504

摘要： Apparatus (FIG. 1) for non-dispersive optical determination of the concentration of an identifiable gas, such as a hydrocarbon, in a mixture such as atmospheric air comprises a sample chamber 13 to contain a sample of the mixture, a source 21 of IR radiation at a wavelength absorbed by the gas beamed through the sample chamber to a detector 22 and transducer means to change the gas pressure within the chamber to determine the change in radiation intensity detected at different pressures. One wall of the sample chamber is formed by a flexible diaphragm 25 driven by a voice-coil type transducer 26 whereby the pressure is switched repetitively between the values above and below atmospheric. Atmospheric gas is admitted to the chamber by a porous plug 24 which restricts flow to a low level permitting a pressure change in the chamber. Absorption by the gas relates the intensity of source radiation I.sub.S and measured radiation I.sub.M by I.sub.M oc I.sub.S .multidot.e.sup.-.alpha. o.sup..multidot.g.multidot.p.multidot.x where x is the radiation path length through the sample, .alpha..sub.o is a constant, p the total pressure of the gas mixture and g the concentration of the hydrocarbon gas. By measuring intensity at different pressure involving a change .DELTA.p and a fractional change in intensity of measured radiation .DELTA.I/I, the gas concentration g is determined by applying the relationship:- g=-.DELTA.I/(I.multidot..DELTA.p.multidot..alpha..sub.o .multidot.x).

摘要翻译： 用于在诸如大气中的混合物中的可识别气体（例如烃）的浓度的非分散光学测定的装置（图1）包括样品室13以容纳混合物的样品，IR的源21 由通过样品室的气体吸收的波长的辐射到检测器22和换能器装置，以改变腔室内的气体压力，以确定在不同压力下检测到的辐射强度的变化。 样品室的一个壁由由音圈型换能器26驱动的柔性隔膜25形成，从而在高于和低于大气压的值之间重复地切换压力。 大气气体通过多孔塞子24进入腔室，其将流动限制到允许腔室中的压力变化的低水平。 气体的吸收通过IM oc ISxe-alpha oxgxpxx与源辐射IS和测量的辐射IM的强度相关，其中x是通过样品的辐射路径长度，αo是常数，p是气体混合物的总压力，g 碳氢化合物气体的浓度。 通过测量不同压力下的强度，包括变化量ΔTA和测量辐射强度DELTA I / I的分数变化，通过应用以下关系式来确定气体浓度g： - g = - DELTA I /（Ix DELTA px alpha oxx） 。

公开(公告)号：US4474471A

公开(公告)日：1984-10-02

申请号：US373770

申请日：1982-04-30

申请人： Jack S. Margolis ,  John V. Martonchik

发明人： Jack S. Margolis ,  John V. Martonchik

IPC分类号： G01J1/44 ,  G01N21/35 ,  G01N21/59

CPC分类号： G01N21/3518 ,  G01J2001/4242

摘要： A correlation spectrometer permanently incorporates a reference cell (12) and an electro-optical phase modulator (EOPM) (50) in the light path between a sample cell (30) and a detector (20). The effect of the EOPM is such that its frequency modulates all of the monochromatic component of the incoherent radiation passing through it. The EOPM is adjusted so that when it is ON all of the energy in the monochromatic components is thrown into sidebands (55) differing from the original frequencies by integral multiples of the modulation frequency, with the total amount of energy absorbed from the original radiation remaining constant. When there is no coincidence between the constituents in the two cells, the detector's output is the same when the EOPM is ON and when it is OFF. However, when there is coincidence the detector's output changes when the EOPM is switched between its two states. The change in the detector's output is related to the quantity of the constituents in the sample cell.

摘要翻译： 相关光谱仪在样品池（30）和检测器（20）之间的光路中永久地包含参考单元（12）和电光相位调制器（EOPM）（50）。 EOPM的作用是使其频率调制通过它的非相干辐射的所有单色分量。 EOPM被调节，使得当它处于ON时，单色分量中的所有能量被投入到与原始频率不同的边带（55）中，该频带与调制频率的整数倍相乘，从原始辐射中吸收的总能量剩余 不变。 当两个单元中的组件之间没有重合时，当EOPM打开时和当OFF时，检测器的输出相同。 然而，当EOPM在其两个状态之间切换时，当符合时，检测器的输出发生变化。 检测器输出的变化与样品池中成分的数量有关。

公开(公告)号：US4393304A

公开(公告)日：1983-07-12

申请号：US235739

申请日：1981-02-18

申请人： Kozo Ishida ,  Hiroji Kohsaka

发明人： Kozo Ishida ,  Hiroji Kohsaka

IPC分类号： G01N1/00 ,  G01N1/24 ,  G01N21/35 ,  G01N21/3504 ,  G01N21/3518 ,  G01N21/61 ,  G01N33/00 ,  G01J1/00

CPC分类号： G01N33/0026 ,  G01N21/3518 ,  G01N33/0006 ,  G01N2001/244

摘要： A gas analyzer of the fluid modulation type includes at least one cell, structure for alternately introducing a sample gas to be analyzed and a reference gas into the cell, a detector for analyzing a property of the sample gas, and an arrangement for alternately discharging the sample gas and the reference gas from the cell. A critical flow device is located in the discharging arrangement. A pump is located in the discharging arrangement and has a capacity for operating the critical flow device under conditions of critical gas flow, thereby maintaining the gas passing through the critical flow device and the cell at a constant flow rate.

摘要翻译： 流体调制型的气体分析装置包括至少一个电池，用于将要分析的样品气体和参考气体交替地引入电池的结构，用于分析样品气体的性质的检测器，以及用于交替地将 样品气体和来自电池的参考气体。 临界流动装置位于排放装置中。 泵位于排放装置中，并且具有在临界气体流动的条件下操作临界流动装置的能力，从而保持气体以恒定流速通过临界流动装置和电池。

公开(公告)号：US3926527A

公开(公告)日：1975-12-16

申请号：US47637374

申请日：1974-06-05

申请人： PHILCO FORD CORP

发明人： PEMBROOK JOHN D ,  BURCH DARRELL E ,  GATES FRANCIS J

IPC分类号： G01N21/61 ,  G01N21/35 ,  G01N1/10 ,  G01J3/48

CPC分类号： G01N21/3518

摘要： A rotating gas cell structure, intended for use in nondispersive electro-optical measurement equipment, includes at least a pair of chambers that, by virtue of rotation of the structure, are alternately inserted into a beam of radiant energy. The chambers contain a quantity of gas of the species to be analyzed at different pressure values. When used in a nondispersive radiant energy gas analyzer, the rotating cell will modulate the radiant energy in a way that permits a sensitive and accurate evaluation of a particular gas in a sample region. If desired the cell structure can include a built-in chopper to improve gas detection performance. In an alternate embodiment one of the chambers can be replaced by a radiant energy attenuator. Gas filling and sealing means for the cell chambers are disclosed.

公开(公告)号：US3899252A

公开(公告)日：1975-08-12

申请号：US48420874

申请日：1974-06-28

申请人： NASA

发明人： DIMEFF JOHN

IPC分类号： G01J1/18 ,  G01N21/35 ,  G01N21/26

CPC分类号： G01N21/3518 ,  G01J1/18

摘要： A nondispersive gas analyzer is provided with means responsive to the fluctuating intensity of radiation passed through a density modulated known and unknown gas sample for generating a signal containing the frequency modulation of the samples. Included in the signal generating means is means for selectively amplifying those components directly related to the frequency of modulation of the known and unknown samples and means for forming a ratio of said components for generating a signal proportional to the density of the known gas in the unknown gas sample.

公开(公告)号：US3869613A

公开(公告)日：1975-03-04

申请号：US40121473

申请日：1973-09-27

申请人： AKRON SCIENT LABS

发明人： LINK WILLIAM T ,  MCCLATCHIE EDWARD A

IPC分类号： G01N21/35 ,  G01N21/26

CPC分类号： G01N21/3518

摘要： Infrared gas analyzers for measuring the presence of specific gas molecules in an unknown gas sample. The gas sample is illuminated by a source of infrared radiation and the radiation passing therethrough is directed to a single radiation detector. A unique absorption filter, generally comprised of a plurality of transparent chambers mounted and rotatable about an axis, is disposed so that the chambers may be caused to sequentially pass through the optical path of the infrared radiation. The plurality of chambers are adapted so as to alternately filter out the characteristic absorption bands of the specific gas molecules being tested for, and to alternately pass radiation of the same energy content which will not be substantially absorbed by the gas being tested for. By comparing the magnitude of the sequential signals derived from the detector, an accurate measure of the specific gas molecules in the unknown sample may be determined. Various embodiments of the invention are disclosed.

摘要翻译： 用于测量未知气体样品中特定气体分子的存在的红外气体分析仪。 气体样品被红外辐射源照射，并且穿过其中的辐射被引导到单个辐射检测器。 通常由围绕轴安装和可旋转的多个透明室组成的独特的吸收滤光器被设置成使得室可以顺序通过红外辐射的光路。

公开(公告)号：US3617737A

公开(公告)日：1971-11-02

申请号：US3617737D

申请日：1969-07-09

申请人： NAT RES DEV

发明人： HOUGHTON JOHN THEODORE ,  PESKETT GUY DENTON ,  RODGERS CLIVE DOUGLAS ,  TAYLOR FREDRIC WILLIAM

IPC分类号： G01N21/35 ,  G01N21/26 ,  G01J5/10

CPC分类号： G01N21/3518

摘要： The invention concerns apparatus for detecting radiation emitted from a quantity of gas, said apparatus comprising a chamber containing a predetermined amount of a given component of said gas having absorption lines in a band of the emission spectrum, means for cyclically varying the pressure of said component in said chamber, and detector means adapted to provide an output signal which is dependent on the radiation intensity wavelengths of the absorption lines or at predetermined wavelengths in the region thereof, said wavelengths being such that the absorption coefficients of the gas at all detected wavelengths are substantially the same, and the radiation is known to originate predominantly from a particular region of the said quantity of gas.

公开(公告)号：US3560735A

公开(公告)日：1971-02-02

申请号：US3560735D

申请日：1968-10-09

申请人： MINE SAFETY APPLIANCES CO

发明人： STRANGE JOHN P ,  FREILINO RAY S ,  BECKER EARL M

IPC分类号： G01J1/42 ,  G01J5/62 ,  G01N21/31 ,  G01N21/33 ,  G01N21/35 ,  G01N21/37 ,  G01N21/61 ,  G01N21/26 ,  G01N21/34

CPC分类号： G01N21/33 ,  G01N21/3103 ,  G01N21/3518 ,  G01N21/37

摘要： A flow responsive detector for use in an infrared gas analyzer includes a pair of gas chambers, at least one of which is adapted to be irradiated by a pulsed beam of infrared energy to produce alternate heating and cooling, and concomitant expansion and contraction, of the gas therein when that gas contains a radiation absorbing component. A sensor responsive to gas flow in the form of a thermistor that has a negative temperature coefficient of resistance and a rate of change of resistance that varies inversely with temperature is mounted in a flow chamber, which is connected by a separate passage with each gas chamber. Where these passages enter the flow chamber, they are provided with jet orifices for directing a high velocity stream or jet flow of gas on the sensor in response to the expansion and contraction of gas in at least one of the gas chambers, thereby greatly enhancing the favorable nonlinear response characteristics of the sensor.

摘要翻译： 分析仪连续地包括红外线源，调制器，含有气体混合物的分析室和检测器以及相关联的电子电路，用于处理由检测器传送的电信号。 调制器周期性地插入吸收待分析的特定气体的特征线的气体参考滤波器的辐射路径，以及不吸收这些线路的测量滤波器。 滤波器通过两个相同的基本滤波器彼此分离，该基本滤波器包括允许灰度传输略低于参考滤波器的平均传输的元件，使得检测器依次递送测量信号和参考信号，该参考信号和参考信号相对于所确定的共同级别 由基本过滤器。 电子处理电路包括用于放大和解复用信号的装置，以及用于建立和读出测量信号和参考信号的商的装置。 这个商只是所寻求的浓度的代表。

公开(公告)号：US3454760A

公开(公告)日：1969-07-08

申请号：US3454760D

申请日：1966-08-29

申请人： HARTMANN & BRAUN AG

发明人： KOWERT ALEXANDER ,  HESSE GRAVENBRUCH ,  MOLDENHAUER KURT ,  RIES LUDWIG ,  SCHAEFER WERNER

IPC分类号： G01J1/42 ,  G01J5/62 ,  G01N21/31 ,  G01N21/33 ,  G01N21/35 ,  G01N21/37 ,  G01N21/61 ,  G01N21/26

CPC分类号： G01N21/33 ,  G01N21/3103 ,  G01N21/3518 ,  G01N21/37

公开(公告)号：US12105020B2

公开(公告)日：2024-10-01

申请号：US17351126

申请日：2021-06-17

申请人： FLIR Systems AB

发明人： Jonas Sandsten ,  Sten Lindau

IPC分类号： G01N21/3518 ,  G02B5/28 ,  G02B13/14

CPC分类号： G01N21/3518 ,  G02B5/281 ,  G02B13/14 ,  G01N2201/0648 ,  G01N2201/0686

摘要： Provided are systems and methods to filter infrared spectrum radiation that can be integrated with a compact optical system for an infrared imaging system. The optical system includes an objective lens element configured to receive and transmit infrared (IR) radiation from a scene, where the IR radiation from the scene includes a particular range of wavelengths corresponding to an absorption spectrum or a transmission spectrum of a gas. The optical system also includes a spectral lens element configured to receive the IR radiation transmitted through the objective lens element, where the spectral lens element comprises a first interference filter disposed on a first surface of the spectral lens element. The interference filter is configured to filter the IR radiation transmitted through the objective lens element to a narrower wavelength band that includes the particular range of wavelengths.