Abstract: Methods and systems can augment 360 degree panoramic LIDAR results (e.g., from a spinning LIDAR system) with color obtained from color cameras. A color-pixel-lookup table can specify the correspondence between LIDAR pixels (depth/ranging pixels) and color pixels, which may be done at different viewing object distances. The operation of the color cameras can be triggered by the angular positions of the LIDAR system. For example, a color image of a particular camera can be captured when the LIDAR system is at a particular angular position, which can be predetermined based on properties of the cameras (e.g., shutter speed). Alternatively or in addition, a common internal clock can be used to assign timestamps to LIDAR and color pixels as they are captured. The corresponding color pixel(s), e.g., as determined using a color-pixel-lookup table, with the closest timestamp can be used for colorization.

Abstract: A pyroelectric presence identification system includes focal plane array and a processor coupled to the focal plane array. The focal plane array includes a first image sensor and a plurality of second image sensors configured to convert radiant energy into an electrical signal. The processor is configured to control the focal plane array in a sleep mode wherein the first image sensor is utilized to detect gross motion of at least one presence and the plurality of second image sensors are de-energized.

Abstract: The present disclosure provides systems and methods for the determining a rate of change of one or more analyte concentrations in a target using non invasive non contact imaging techniques such as OCT. Generally, OCT data is acquired and optical information is extracted from OCT scans to quantitatively determine a flow rate of fluid in the target; angiography is also performed using one or more fast scanning methods to determine a concentration of one or more analytes. Both calculations can provide a means to determine a change in rate of an analyte over time. Example methods and systems of the disclosure may be used in assessing metabolism of a tissue, where oxygen is the analyte detected, or other functional states, and be generally used for the diagnosis, monitoring and treatment of disease.

Abstract: Haemodynamic parameters such as the amplitude and phase of a pulse wave passing through a region of interest can be obtained from a video image of the exposed skin of a patient by processing of the reflectance photoplethysmographic signal using signal averaging. The region of interest is defined and a reflectance photoplethysmographic signal obtained by finding the mean pixel intensity across the region of interest for each video frame. Signal averaging is performed on the resulting pulsatile waveform by detecting peaks in the waveform, selecting those parts of the waveform which lie within a window centered on the peaks, and summing the selected parts of the waveform to find an average pulse waveform. The region of interest is then divided into sub-regions and an average pulse waveform for the video sequence is found for each of the sub-regions in the same way.

Abstract: Method of measuring the thickness of a layer by a light source irradiating the layer with a light beam, which light source is controlled by a sinusoidal control signal having a modulation frequency fm so that the light beam presents optical power that is sinusoidally modulated at the modulation frequency, the measurement method consisting in: using detector elements to determine a calibration phase shift (??cal) between the optical power and the control signal; heating the layer with the light beam; using the detector elements to detect a sinusoidal component of a heat flux radiated by the layer; calculating a phase shift (??th/opt) between the sinusoidal component of the radiated heat flux and the optical power of the light beam while taking account of the calibration phase shift; and determining the thickness of the layer of material as a function of the phase shift (??th/opt).

Abstract: An embodiment of the invention relates to an apparatus for dispensing liquid, which apparatus detects an object and controls the dispensing of liquid. The apparatus includes a first signal source which generates a first beam pulse and a second signal source which generates a second beam pulse and the propagation paths of the beam pulses intersect in relation to each other. The apparatus also includes a receiver which receives reflected parts of the first beam pulse and receives reflected parts of the second beam pulse, the parts reflected from the first and second beam pulses being reflected from the object which is located on the propagation path of the first and the second beam pulse. Furthermore, the system comprises a signal processing unit detects said object based on the parts reflected from the beam pulses and, based on this detection, controls the dispensing of liquid.

Abstract: An apparatus and methods for estimating a chromaticity of illumination from raw image data. In an embodiment, one or more image chromaticity weight is determined based on a distance between the raw image data in a sensor chromaticity space and a nearest point within a locus of sensor illumination chromaticities. In a further embodiment, one or more image chromaticity weight is determined based on a disparity among normalized color channel values. In certain embodiments, image chromaticity estimates are utilized to determine a white point estimate for the raw image data. In embodiments, an electronic device including a camera estimates the chromaticity value of raw image data captured by the camera as part of an AWB pipeline. The electronic device may further determine, for example as part of the AWB pipeline, a white point estimate based, at least in part, on the raw image data chromaticity value estimate(s).

Abstract: The present invention relates to a position identification system and a method for gesture identification thereof. The method for gesture identification does not use the conventional digital image capture method, instead, the method uses IR detection. In order to accurately detect the movement track of the external object, in the present invention, at least two IR LED are provided. When the first IR LED emits the IR ray signal, the second IR LED is used for receiving IR ray signal. Moreover, the present invention determines the distance between the external object and the IR LEDs by detecting the emitting IRs with different energy. Further, the present invention adopts TDM (Time Division Multiplexing) such that the present invention can grasp the distance between the first IR LED and the external object and the distance between the second IR LED and the external object. Thus, the relative position of the external object can be captured.

Abstract: In a method for controlling a multi-color output of an image of a medical object for assisting medical personnel, the medical object is illuminated with light with an illumination spectrum. By means of an image sensor, image data are acquired for a group of one or more color channels. Image information concerning an additional color channel, which is not among the group of one or more color channels, is generated depending on the acquired image data. An image output device for multi-color output of the image is controlled depending on the acquired image data and the acquired image information.

Abstract: Systems and methods for color correcting radiation by alternately focusing a first radiation spectrum on a first radiation spectrum detector, and then focusing at least one additional radiation spectrum on at least one additional radiation spectrum detector.

Abstract: A terahertz wave transceiver configured to generate and detect terahertz waves based on time-domain spectroscopy includes a photoconductive device having a photoconductive film, a first electrode, and a second electrode. An excitation light illumination region is formed between the first and second electrodes. A bias applying unit applies a bias between the first electrode and the second electrode to generate the terahertz wave in the excitation light illumination region. A current detection unit detects a terahertz-wave current that is a component of a current generated in the excitation light illumination region and that is generated by an electric field of a received terahertz wave arriving from the outside. A current drawing unit draws a current originating from the bias applied by the bias applying unit. An adjustment unit determines the amount of the current drawn, based on the amount of the bias applied by the bias applying unit.

Abstract: A non-contact thermal imaging system for heterogeneous materials, the system including a translating head that is parallel to a reference plane; an infrared probe connected to data acquisition electronics in order to collect first data, the first data being nitrated intensity readings; a transmitter for sending one or more signals to a sample; and a receiver for receiving the one or more signals from the sample; wherein the transmitter and the receiver measure an intensity of the one or more signals reflected off the sample as second data; and wherein the first data and the second data are combined via software to calculate a temperature at every point on the sample.

Abstract: A gas sensor arrangement for detecting the presence or concentration of an analyte in a measuring gas comprises a gas measuring chamber having an inlet for receiving the measuring gas. A measuring radiation source is arranged in the gas measuring chamber. The measuring radiation source emits radiation in a non-uniform pulse sequence according to a signal from a controller. A radiation detector receives the radiation emitted from the measuring radiation source. The radiation detector sends an output signal to the controller for processing.

Abstract: An interface assembly is provided for interfacing an imaging engine having an adjustable lens assembly to a circuitry assembly of an optical code reader system, the interface assembly includes a first coupling circuitry assembly for transmission of at least one input signal in a first direction from the circuitry assembly toward the imaging engine, the at least one input signal including at least one focus control signal for controlling the lens assembly for selecting a focus position of at least two focus positions, and a second coupling circuitry assembly for transmission of at least one output signal in a second direction from the imaging engine toward the circuitry assembly, the at least one output signal including at least one pixel data signal, wherein the at least one pixel data signal is indicative of light sensed by a photo sensor array of the imaging engine. Preferably, the imaging engine is removably positioned and/or dimensioned and configured to fit within a predetermined form factor.

Abstract: In thermography apparatus, a lamp 102 is modulated sinusoidally and a camera 106 captures thermal images at the modulated frequency, but delayed by an adjustable preset delay. A signal delay box 107 is connected between a sinusoidal modulation signal function generator 104 and the camera 106. The delay box introduces a delay to the function generator signal so that the thermal image is captured after a period of time, resulting in an enhanced image.

Abstract: Offset arrangement for an infrared detector array, which continuously adjusts the offset in a recursive process. With the aid of a displacement device the image observed by the detector array is continuously shifted over a small distance, the apparent intensity changes arising for a pixel being used for adjusting the offset.

Abstract: A system and method for generating signals representing infrared radiation include the capability to provide a reference scene and an actual scene to a plurality of infrared detector elements arranged in a two-dimensional array, the detector elements being biased so that they produce a signal even when no infrared radiation is impinging thereon. The system and method further include the capability to receive a first signal representing the reference scene from one of the detector elements, receive a second signal representing the actual scene from the detector element, and remove the bias signal from the second signal. The system and method also include the capability to attenuate the remaining second signal, integrate the attenuated signal, and sample the integrated signal.

Abstract: The present invention provides for an improved electromagnetic radiation detector having a micromachined electrostatic chopping device. The MEMS flexible film chopping device provides reliability, efficiency, noise reduction and temperature fluctuation compensation capabilities to the associated electromagnetic radiation detector. An electromagnetic radiation detector having an electrostatic chopper device comprises a detector material element, first and second electrodes in electrical contact with the detector material element and electrically isolated from one another. Additionally, the chopper device will incorporate a flexible film actuator overlying the detector material layer and moveable relative thereto. The flexible film actuator will typically include an electrode element and a biasing element such that the actuator remains in a fully curled, open state absent electrostatic voltage and moves to a fully uncurled, closed state upon the application of electrostatic voltage.

Abstract: The invention is a fast-scanning ODT system that uses phase information derived from a Hilbert transformation to increase the sensitivity of flow velocity measurements while maintaining high spatial resolution. The significant increases in scanning speed and velocity sensitivity realized by the invention make it possible to image in vivo blood flow in human skin. The method of the invention overcomes the inherent limitations of the prior art ODT by using a phase change between sequential line scans for velocity image reconstruction. The ODT signal phase or phase shifts at each pixel can be determined from the complex function, {tilde over (&Ggr;)}ODT(t), which is determined through analytic continuation of the measured interference fringes function, &Ggr;ODT(t), by use of a Hilbert transformation, by electronic phase demodulation, by optical means, or a fast Fourier transformation. The phase change in each pixel between axial-line scans is then used to calculate the Doppler frequency shift.

Abstract: A sensor arrangement and system facilitate the measurement of polarized light intensities for use in object identification and classification. In an example embodiment, an imaging sensor for polarizing light from a light source includes an array of light detecting elements that converts light into a plurality of photocurrent signals. The sensor also includes a rotatable disk positioned between a light source and the light detecting array and parallel to the light detecting array. The rotatable disk includes a plurality of linear members that are opaque and parallel to each other that polarize light from the light source passed to the light-detecting array. The sensor further includes a circuit arrangement configured to generate a data set of polarization vector components, the polarization vector components being generated as a function of a set of the photocurrent signals that are sampled as a function of a position of the rotating disk.

Abstract: A beam-limiting aperture truncates selected portions of a charged particle beam illuminating portions such as subfields of a patterned reticle of a charged particle beam projection lithography tool and then projects a pattern of charged particles onto a target in a charged particle beam lithography tool. The respective portions of the reticle are patterned in accordance with respective portions of an integrated circuit or other desired pattern and may have differing transmissivities; altering beam current at the target even when source beam current remains substantially constant. The portion of the beam which is truncated, thus altering the particle trajectory semi-angle and numerical aperture of the tool is controlled in accordance with the transmissivity of the reticle portion to enhance resolution to near optimal limits.

Abstract: In an infrared sensor including a compensating element and an infrared sensitive element, the main bodies of which consist of temperature-sensing layers of germanium and are supported on a single-crystal silicon substrate with bridge structures of silicon oxynitride layers; infrared protection layers individually made of aluminum and/or gold with a thickness of 0.1-1.0 &mgr;m formed on both sides of the main body of the compensating element via insulating layers of silicon oxynitride of about 0.1-10 &mgr;m for almost completely shielding the compensating element from incident infrared rays and improving the sensor's sensitivity.

Abstract: A chopper is provided of solid state construction. Two layers are provided adjacent one another with the area between the layers defining one or more diffusion zones. One or more voltage potentials may be applied across the second layer to correspond to the diffusion zones. At an initial state the voltage potentials are either zero or some predetermined value which causes the index of refraction of the two layers to be substantially the same. At a second state the voltage potential equals some predetermined value to cause the index of refraction of the second layer to be different from that of the first layer. The difference in index of refraction between the layers creates a diffraction grating in the respective diffusion zone to diffuse that portion of an incident signal passing through the diffusion zone.

Abstract: Thermal imaging chopper (20) may comprise a disk (40) formed of a thermally transmitting material. The disk (40) may include a structure (44) operable to randomly scatter thermal radiation of the scene (14).

Abstract: An infrared imaging microscope uses spatial encoding to divide an sample being examined into a plurality of pixel regions. The spatial encoding is provided by a digitally controlled mask, which is preferably a multiple mirror array, and which masks the imaging radiation directed from a radiation source to the sample. The signal reflected or transmitted from the sample is detected using a single-element detector. As the mask pattern provided by the mask changes, the output signal of the detector is monitored, and the spectroscopic composition of each of the pixel regions is resolved using a spatial decoding method, such as a Hadamard transform. The digital control of the mask allows fast, easily-implemented changes to the masking pattern, and provides a low processing load relative to imaging devices that use multiple-element detectors.

Abstract: A low cost infrared camera (1) for night vision. The camera (1) is disposed within a housing (2) having an infrared transmissive window (6) disposed at an input aperture (5) thereof. A compact optical arrangement (10) is disposed within the housing (2) to focus energy from the window (5) onto a focal plane array (20). A chopper disk (19) is positioned between the reflective optical arrangement (10) and the focal plane array (20) to establish a reference level for the array (20) and to facilitate a sequential readout thereof. A signal processing circuit (100) is included for processing the output of the array (20) for display on a standard video screen. Thus, the problems with uncooled detectors are overcome by use of a fast optical system in combination with an uncooled detector. The fast optical system provides a high signal level to the uncooled detector, thereby compensating for losses in collection of thermal radiation.

Abstract: A thermal imaging system (10) contains a focal plane array (14) including a plurality of thermal sensors (50) mounted on a substrate (52). The focal plane array (14) generates both a reference signal which represents the temperature of the substrate (52) and a biased signal corresponding to the total radiance emitted by a scene (11). Electronics (16) process the reference signal and the biased signal to obtain an unbiased signal representing radiance differences emitted by objects in the scene (11). A thermoelectric cooler/heater (38) may be provided to optimally adjust the temperature of the substrate (52) to improve overall image quality. Each thermal sensor (50) contains an electrode (66 and 68) that electrically couples the thermal sensor (50) to the substrate (52) and also allows the thermal sensor (50) to deflect, contact, and thermally shunt with the substrate (52).

Abstract: RF modulation spectroscopy of a near infrared laser diode source is used to determine the amount of a target substance in a breath sample. In this type of modulation the laser output is modulated to produce sidebands displaced from the laser carrier by the modulation frequency. The modulated beam is passed through a gas sample which differentially absorbs the sidebands, the result of which is the conversion of some of the laser frequency modulation into amplitude modulation which is subsequently detected using a broadband photodetector. In certain tests, the target substance is a particular isotope, whose concentration is measured as an isotope ratio. In order to measure the presence of first and second isotopic species, provision is made to provide laser illumination at characteristic wavelengths for absorption lines for the first and second isotopic species of the gas.

Abstract: A detector for detecting hot spots that includes an infrared sensor and a scanning component. The infrared sensor is fixedly mounted on a housing and is oriented to have a field of view of at least part of the region of interest. The scanning component is mounted in front of the infrared sensor and blocks most of the field of view of the infrared sensor and has a moving aperture that exposes the infrared sensor to a small area of the region at one time. The moving aperture provides a small instantaneous field of view and over time exposes the sensor to a much larger area.

Abstract: A method and apparatus for the detection of pits and abnormalities in various stone fruits. The apparatus transmits a first plurality of beams of light (18) across inspection zone (14) and transmits a second plurality of beams of light (22) across inspection zone (14) in a direction opposite to beams of light (18). As a stone fruit (10) passes through inspection zone (14), a first plurality of sensors (32) and a second plurality of sensors (34) detect the variations in the intensity of the transmitted beams of light. The light transmittance and reflectance characteristics of the stone fruit are analyzed to detect the presence of a pit or internal or external abnormality.

Abstract: A chopper, in an infrared imaging system, is used to scatter infrared radiation from a viewed scene. This scattered radiation is detected with an infrared detector and used to produce a reference signal, which represents the uniform average radiance of the scene. This reference signal may be substracted from a signal representing the unscattered radiation emitted by the scene, to produce a signal that represents only radiance differences and that is an optimal signal for amplification.

Abstract: In a pyroelectric infrared detector, there is provided a member having a slit positioned in front of an array of pyroelectric elements, which interrupts an infrared image which is incident on the pyroelectric element array, and respective pyroelectric elements forming a row of the pyroelectric element array are wired so that they are connected in series electrically and adjacent pyroelectric element generate counter-electromotive forces. An infrared image irradiated on respective pyroelectric elements is scanned successively by the movement of the slit member along a row of the pyroelectric element array, thus obtaining information relating to an infrared intensity distribution from a heat source which emits IR rays which are being irradiated onto respective pyroelectric elements, from time series signals produced at both ends of the pyroelectric element array.

Abstract: A circuit arrangement for providing a pulse modulated power feed to an infrared radiation source is disclosed. The radiation of the radiation source is detectable by a receiver and the circuit arrangement is improved such that the radiation source is as independent as possible from its radiation characteristics as well as from its thermal characteristics and can deliver a rapid and easily processable measuring signal to the receiver uninfluenced by ambient conditions. For this purpose, the power feed is controllable by means of a control unit during the pulse duration to an upper temperature desired value To and, during the no-pulse period, the power supply is controllable to a lower temperature desired value Tu with the alternation between the two desired values being triggered by a pulse generator connected to a desired value input of the control unit.

Abstract: The disclosure relates to a system for on-line normalization of the outputs of all of the detector elements of an infrared detector wherein, during the retrace period of the scanning mirror, infrared energy from a controlled thermoelectric source is reflected first from a high reflectivity sector of a rotating mirror and then from a relatively low reflectivity sector of the rotating mirror onto the detector. The detector output for the high and low reflectivity input signals is analyzed on a channel by channel basis by software controlled hardware and the gain of each channel is then adjusted in response thereto by the software controlled hardware individually. In this manner, each channel is caused to provide the same output for an identical input thereto.

Abstract: A CT computed tomograph comprises a scanner (51) which surrounds a living body of a person to be examined. Ultrashort light pulses of the ith wavelength are applied to the living body from a sample light transmitting path (80k) corresponding to the kth cell of this scanner and the sample light pulses received by a sample light receiving path (81l) corresponding to the lth cell and reference light pulses transmitted from a reference light path (79) and a delay light path (78) are converged by a converging lens (75). A CPU(64) counts photons outputted from a photomultiplier (22) based on the converged light pulses and calculates an average value by averaging a predetermined number of count values. A delay amount of the reference light pulses through the delay light path (78) is changed based on the average value and, based on delay time and an average value in the delay time, a photon count value S.sub.

Abstract: An electromagnetic radiation detecting device comprises at least one radion detector for detecting electromagnetic radiation from a hemisphere, a radiation-transparent protective hood covering the or each detector, and a rotary chopper to alternately shield the or each detector and associated hood from arriving radiation and to expose the detector and hood to such radiation. The chopper comprises a carrier disc, which is rotatable about an axis parallel to a radiation-receiving area of the or each detector, and at least one hollow semicylindrical shielding member fixed at the periphery of the disc and curved in the axial direction of the semicylindrical shape. The or each shielding member is movable on a circular path by the disc to alternately shield and reveal the hood covering the or each detector.

Abstract: The disclosure is directed to a modulation device for a radiation detector device picking up an image field. The modulation device comprises a modulation disk disposed in the image field plane and having radial slits, said modulation disk executing a nutation about the axis of the image field. The modulation device further includes an optical system, a radiation-sensitive receiver arrangement and a signal processor. The radiation-sensitive receiver arrangement (11) comprises a grouping of radiation reception elements (E11 to Emm) forming a radiation receiver field (13), which elements are coupled with a window circuit (18, 22, 32) and are selectively addressable by the window circuit for the formation of at least one window zone within the radiation receiver field (13). The addressing occurs such that only signals of this at least one window zone are transmitted into the signal processor.

Abstract: A spectroscopic measurement system comprises at least two kinds of diffraction gratings whose grating surfaces are in line, an exchange device for exchanging the positions of the two kinds of diffraction gratings in connection with incident light to be measured while the two kinds of diffraction gratings are placed in a predetermined rotation angle, at least two kinds of detectors having characteristics corresponding to those of the two kinds of diffraction gratings respectively, a light path switch for switching a path of diffraction light toward either of the two kinds of detectors, and a switch circuit for switching the detection output of the two kinds of detectors in synchronization with the exchange operation of the two kinds of diffraction gratings.

Abstract: An apparatus for intermitting beams of light for use in a gas analyzer in which a rotary shaft of a chopper is supported by first and second ball bearings. An outside ring of the first ball bearing is fixedly mounted on a bearing housing and either an inside ring or an outside ring of the second ball bearing is adapted to be movable in the thrust or axial direction relative to the rotary shaft, whereby the second ball bearing is movably energized in the thrust direction by an elastic member to eliminate shake of the rotary shaft due to play in the ball bearings and thus reduce modulation noise to improve measuring accuracy of the gas analyzer.

Abstract: A gas cell array absorbs infrared energy radiated by a viewed scene. A la interferometer has its resultant intensity changed by the cell's changing length. This is monitored by a vidicon tube that feeds the signal to a digitizer and onto a video display. The incident infrared radiation is chopped into quantized amounts of energy and memory units receive the digitized output of the vidicon tube. Subtractors receive vidicon tube signals simultaneously with quiescent reference levels data. The subtractors form a difference signal by subtracting the quiescent reference level signal from the immediate signal being passed to control threshold detectors. An extended dynamic range of 1,000:1 is accomplished for the preferred embodiment.

Abstract: In an infrared detector, a shutter is employed in an elastic wave element of a feedback type of oscillator containing the elastic element so that the elastic element receives infrared light intermittently. The period during which the number of peaks of the oscillation output waveform from the oscillator exceeds a predetermined value is set to be the opening or closing period of the shutter, the number of clock pulses from a clock signal generator is counted during the shutter opening or closing period, and the difference between the counted values is obtained, thereby detecting the energy of the infrared light. This detector features not only an extremely high sensitivity, but a high detection accuracy, as well as the production of a digital output.

Abstract: A bifunctional sensor is disclosed for an optical seeking system which utzes a single focussing lens arrangement for focussing light of two distinct wavelength ranges. A first detector for detecting light of the first wavelength range is provided nearest the lens system and transmits light of the second wavelength range. A second detector for detecting light of the second wavelength range is provided behind the first detector with a modulating apparatus for modulating the light of the second wavelength range before it reaches the second detector.

Abstract: Local heating is employed to scale a workpiece, the heat dissipating from the heated zones after such scaling.

Abstract: A method and apparatus for determining a property of a material (10) utilizes a source (28) of measuring radiation and reference radiation, a measuring information channel including a detector (30) for the measuring radiation, and a reference information channel including a detector (32) for the reference radiation. A channel-monitoring radiation is also produce. In a standardizing mode, a monitor-standardization response (M.sub.11 or R.sub.11) is derived from each of the two channels while passing monitoring radiation to both detectors and a source-standardization response (M.sub.12 or R.sub.12) is derived from each of the two channels while passing measuring radiation to the measuring detector and passing reference radiation to the reference detector. In an operating mode, an operation-monitoring response (M.sub.21 or R.sub.21) is derived from each of the two channels while passing monitoring radiation to both detectors and a material-condition response (M.sub.22 or R.sub.

Abstract: A method and apparatus for detecting optical radiation by optically monitoring temperature changes in a microvolume caused by absorption of optical radiation to be detected. More specifically, a thermal lens-forming material is provided which has first and second opposite, substantially parallel surfaces. A reflective coating is formed on the first surface, and a radiation-absorbing coating is formed on the reflective coating. Chopped, incoming optical radiation to be detected is directed to irradiate a small portion of the radiation-absorbing coating. Heat generated in this small area is conducted to the lens-forming material through the reflective coating, thereby raising the temperature of a small portion of the lens-forming material and causing a thermal lens to be formed therein. The thus-formed thermal lens is optically detected by irradiating the thermal lens by a collimated light beam.

Abstract: A Stark effect spectrophone is provided using a pulsed or continuous wave laser (33) having a beam with one or more absorption lines of a constituent of an unknown gas. The laser beam is directed through windows (31,032) of a closed cell (30) while the unknown gas to be monitored is caused to flow continuously through the cell between electric field plates (34, 35) disposed in the cell on opposite sides of the beam path through the cell. The plates are so disposed as to be divergent, e.g., flat plates at an oblique angle relative to each other, or plates shaped according to a mathematical function so that, with constant voltage applied across the plates, there is a linear variation in electric field strength along the beam path. Discrete pressure transducers (37) are positioned at field strength points of interest.

Abstract: A balancing radiometer for measuring the intensity of incident electromagnetic radiation comprises: a pair of identical sensors, each including a thermally conductive substrate, at least one surface of the substrate being comprised of an electrically insulating material, and means disposed on the one surface for resisting the flow of electric current and absorbing incident radiation; means for shielding one of the two sensors from the radiation source, the other sensor being unshielded; means disposed in thermal conducting relation with the substrate of the shielded sensor for providing a first signal proportional to the temperature of the shielded sensor; second means disposed in thermal conducting relation with the substrate of the unshielded sensor for providing a second signal proportional to the temperature of the unshielded sensor; means for comparing the first and second signals; variable power supply means responsive to the signal comparing means; means for connecting the power supply means to the shi

Abstract: A system for eliminating background signals in chopped infrared measuring systems employs operational amplifier principles for subtracting a reference signal of proper amplitude, phase and frequency from the background-plus-signal radiation. The output is converted to a dc voltage level directly related to incident flux.