Abstract: A satellite method for measuring sea surface temperature uses simultaneous overage by two satellites in the same spectral window plus a simplified atmospheric radiative transfer model. A geostationary satellite and any polar orbiting satellite provide nearly coincident infrared imagery of a given area with points of equal and unequal observation angles. The calibration curve of the data for one satellite is adjusted to match the temperatures of the better calibrated satellite data along the equal angle points. A difference image is obtained from the resulting two satellite temperature images. The difference image together with the two observation angles and the temperature of the more accurate satellite radiometer are input to a suitable atmospheric model to obtain sea surface temperature at each point in the study area. The result is an accurate sea surface temperature for each point within a given area which is corrected for a spatially variant atmosphere.

Abstract: Military mechanical field equipment, such as an electrical generator, is camouflaged from airborne IR detection by enclosing the equipment in a double-walled enclosure having hollow walls through which air is forced to flow. By adjusting the air flow in the enclosure, the radiance from the enclosure can be made the same as its immediate surroundings. A dual temperature sensor senses temperature differences between the enclosure surface and the surroundings and varies the air cooling accordingly until thermal balance is achieved.

Abstract: A device for measuring the two-dimensional temperature profile of a surface comprises imaging optics for generating an image of the light radiating from the surface; an infrared detector array having a plurality of detectors; and a light pipe array positioned between the imaging optics and the detector array for sampling, transmitting, and distributing the image over the detector surfaces. The light pipe array includes one light pipe for each detector in the detector array.

Abstract: A detector for a gas analyzer includes a thermal detector, an absorptive film on the surface of said thermal detector, and an enclosure containing a reference gas of the gas species of interest such that the thermal detector is in thermal contact with both the absorptive film and the reference gas. During irradiation, the absorptive film absorbs radiation which passes through the reference gas and causes the thermal detector to generate a corresponding output. When the irradiation is terminated, the heat content of the reference gas, which will be dependent upon the amount of the radiation absorbed, will be communicated to the thermal detector to cause the thermal detector to provide a second output representing the amount of radiation absorbed by the reference gas.

Abstract: A pyroelectric detector comprising a functional portion in which opposed electrodes 111 to 118 are formed on both surfaces of a pyroelectric type substrate 101 and four light receiving electrode portions a, b, c and d are structured by the opposed electrodes 111 to 118. Among the light receiving electrode portions a, b, c and d, the light receiving electrode portions a and c in odd-numbered positions constitute one light receiving electrode group A and the light receiving electrode portions b and d in even-numbered positions constitute the other light receiving electrode group B. The light receiving electrode portions a and c and the light receiving electrode portions b and d are electrically connected alternately and in series, and the light receiving electrode group A and the other light receiving electrode group B are connected to have opposite polarities.

Abstract: To be of most use as an input signal for the control system of a gas turbine aeroengine, a pyrometer-derived turbine blade temperature signal should represent the average temperature of the hottest parts of the blades with fast and accurate response when the average temperature of the hottest parts changes with engine conditions. The invention achieves this by providing the pyrometer with an optical system adapted to give the pyrometer's photo-diode a large field of view which is rectangular at the face of the turbine rotor and which extends an integer number of inter-blade passage widths in the circumferential direction and a portion of the length of the blade aerofoils in the radial direction.

Abstract: An electrical heating system for buildings is described in which the output voltage to a resistance heater is varied in accordance with outside temperature. The disclosure includes system means for compensating for solar radiation and wind effects. Also, night setback and morning start up are provided. The heat present on the interior of the building is provided in accordance with the building characteristics and without regard to interior temperatures.

Abstract: An infrared sensor made of LiTaO.sub.3 is provided on a ceiling of a heating chamber of a microwave oven, and a chopper is provided so as to intermittently block infrared radiation emitted from food in the heating chamber. The infrared sensor is brought to face the food and the chopper alternately and provides a corresponding AC output signal. The temperature of the chopper is detected from the output signal of a separately provided chopper temperature sensor consisting of a thermister. The detected chopper temperature output signal is corrected in a microcomputer to be substantially in accord with chopper temperature components in the output signal of the infrared sensor. The corrected chopper temperature data is applied to the infrared sensor output data for removing the chopper temperature components from the output signal of the infrared sensor to obtain a food temperature signal corresponding to the sole temperature of the food.

Abstract: A radiation detector includes a flat housing 14 having a radiation sensor 16 at one end thereof and a bar graph display 18 at the other end thereof. The bar graph display provides an indication of radiation sensed from a limited surface area as the sensor is scanned across an extended surface area. The width of the housing 14 is such that, when the housing is held at about arm's length in the line of sight, the width defines a field of view which approximates the field of view of the radiation sensor.

Abstract: A method for the structural, superficial and deep analysis of a body is disclosed. The method includes scanning the body to be examined using a modulated excitation radiation beam so as to impart a thermal modulation to the body. The thermal modulation is then measured on the side of the body distal to the side exposed to the beam. The amplitude as well as the phase of the measured thermal modulation is used to determine the thickness and structure of the body. A device for accomplishing the above described method is also disclosed.

Abstract: A perimeter heat loss control system for electrical heaters and/or radiant ceiling panels around the periphery of a building has the heaters divided into zones, usually one zone for each outside wall. In a zone, a radiant heat responsive heat flow sensor faces the outside wall for the zone and generates a wall heat rate signal; a thermal sensor is positioned adjacent to one heater to generate a heat rate signal. A zone comparator uses the sensor signals to generate an error signal representative of deviation of the differential between the rate of heat flow through the zone wall and the rate of heat generation in the zone relative to a predetermined preset value. That error signal is applied to a power control to control all heaters in the zone, proportionally varying the input to the heaters until a balanced heat loss condition is realized.

Abstract: The present invention is a thermometer used for measuring furnace temperaes in the range of about 1800.degree. to 2700.degree. C. The thermometer comprises a broadband multicolor thermal radiation sensor positioned to be in optical alignment with the end of a blackbody sight tube extending into the furnace. A valve-shutter arrangement is positioned between the radiation sensor and the sight tube and a chamber for containing a charge of high pressure gas is positioned between the valve-shutter arrangement and the radiation sensor. A momentary opening of the valve shutter arrangement allows a pulse of the high gas to purge the sight tube of air-borne thermal radiation contaminants which permits the radiation sensor to accurately measure the thermal radiation emanating from the end of the sight tube.

Abstract: Remote measurement of temperature variations within polymer process melts is performed by irradiating the melt with a collimated radiation source such as laser light and relating the transmitted radiation to the temperature distribution within the melt. A method and apparatus for temperature profile determination is based upon the variation of light transmittance through the melt as a function of temperature and wavelength of the incident light.

Abstract: A probe for measuring temperatures in a hot gaseous medium such as the gases inside the shaft of a blast furnace. A first tubular member extends from a base structure such as a blast furnace wall into the gaseous medium. Successively smaller, second and third tubular members are concentrically positioned inside this exterior tubular member. Preferably, an exterior protective member also surrounds the first tubular member. A refractory material is interposed between the exterior protective member and the first tubular member to minimize temperature fluctuations in the body of the probe itself. Thermocouple leads extend longitudinally in an air space between the second and third tubular members and then protrude to the exterior of the probe. A forward fluid coolant passageway is formed inside the third tubular member.

Abstract: A pyroelectric detector with an optimized quality factor, having a dielectric material inserted between two parallel electrodes, the material being a monodomain ferroelectric monocrystal. The faces of the monocrystal in contact with the electrodes form an angle differing from 90.degree. with the polar axis of the monocrystal. The detector is useful in infrared imaging and detection.

Abstract: A granular superconducting thin film bolometer made by anodizing a thin film of such materials as niobium nitride to form a thin granular film separated by and covered with the anodized oxide. The bolometer is cooled to its superconducting state and electrically connected to a biasing and detecting network. Its temporal response is better than 1 ns.

Abstract: The microwave oven includes a heat chamber, an infrared detector for detecting infrared rays irradiated from an object to be heated in the heating chamber, a chopper for alternately interrupting the path of infrared rays to the detector, an oscillator for producing a reference signal used for driving the chopper, and a circuit for regulating the output of the detector and the phase of the reference signal. The infrared detector does not require any phase adjustment to accommodate frequency shifts due to fluctuations in the power frequency.

Abstract: A hand-held digital readout thermometer measures temperatures over the range -50.degree. C. to +1100.degree. C. with a maximum error less than 3.degree. C. in that range. The thermometer includes a thermocouple, a temperature stable and temperature independent power supply, a temperature stable differential first amplifier, a second amplifier that compensates for the nonlinear response of thermocouple voltage to temperature, and an analog/digital converter controlling a digital display indicating temperature according to a preselected scale. A particular feature of the invention is a latching comparator capable of activating a low battery indicator when the supply voltage drops below a preselected value.

Abstract: Disclosed are a method of and apparatus for radiation pyrometric temperature measurement of a continuous cast metal bar. Cast bar advancing from a continuous casting machine is continuously monitored for temperature without contacting the cast bar with any apparatus by applying a layer of soot onto the surface of the bar, detecting infrared radiation emitted from the sooted area, converting the detected radiation into a temperature signal, displaying the temperature, and completely removing the soot from the cast bar before it enters a rolling mill.

Abstract: The thermal gain sensor detects, by a simplified method, the direction of net energy flow through a fluid-separation barrier (window). In particular, the sensor determines a balance point above which the radiant energy (solar, microwave, X-ray, etc.) gained through the barrier exceeds the energy lost through the barrier from the combined effects of convection and conduction.One application of the thermal gain sensor pertains to a solar energy collector or solar heated room. The sensor controls movable insulation panels or curtains which reduce the energy flow through the collector window (barrier) when the energy flow is in the wrong direction. The sensor may be used to either maximize or minimize the energy in the collector or room.The sensor simulates the absorptivity and convection loss of the controlled environment by means of an insulated, darkened disk slightly spaced from the barrier surface.

Abstract: A system for the measurement of temperatures in a reactor such as those operated under high pressure and/or temperature is disclosed. The temperature is measured by the use of a pyrometer which is in optical communication with a measuring duct which can be disposed in the wall of the reactor and is in optical communication with the reactor interior. The measuring duct comprises two concentric tubes the outer one of which extends beyond the inner tube in the direction of the reactor interior and has a conical construction immediately following the termination of the inner tube. The concentric tubes are provided with a common end section such as in the form of a cone in the direction of the reactor exterior. A hermetic housing defining a safety chamber is disposed exterior thereof, the hermetic housing having two opposed pressure type and heat resistant windows in alignment with the inner tube and the pyrometer. The hermetic housing is not normally permanently attached to the measuring duct.

Abstract: Apparatus and method for indicating stress in an object comprising viewing the temperature variation of part of the surface of the object as it is stressed. An infra-red detector detects small changes of temperature and the stress may be applied by natural loading or by cyclic stressing imposed by a vibrator.

Abstract: A photoluminescent indicator apparatus having automatic feedback means to maintain the sensitivity of the indicator apparatus with respect to variations in environmental conditions. The apparatus includes a sample of photoluminescent material having a photoluminescent decay rate which varies as a function of environmental conditions. The sample is positioned in a remote location having some unknown aspect of the environment desired to be measured. The sample is optically excited with a modulating signal to generate an excitation output signal functionally dependent on the modulating signal and indicative of the unknown environmental condition. A phase detection means is provided for comparing difference in phase between a phase reference signal and the excitation output signal to generate a phase differential signal functionally related to the photoluminescent decay rate of the sample.

Abstract: In a thermal radiation measuring arrangement, a thermal radiation detector is located at the focal point of a collecting mirror, upon which incident thermal radiation from a surface, such as a building wall, is directed. The thermal radiation detector may be, for example, a thermopile, and provides an output signal having a magnitude proportional to the amount of thermal radiation which it receives. The temperature detection means detects the temperature of the thermal radiation detector and, for example, may detect the cold junction of the thermopile. In a first operating condition, a signal summing means receives the output signal from the thermal radiation detector and the temperature detection means and provides a third output signal proportional to the sum of these first and second output signals. In a second operating condition, a signal biasing means is connected into the signal summing means.