Abstract: A temperature monitoring unit has a high degree of sensitivity and reliability even when monitoring the temperature of a relatively large rotary heating element. The temperature monitoring unit includes a mirror which is provided in the vicinity of the rotary heating element and is oriented to reflect infrared rays from the heating element in the radial direction thereof, the mirror being reciprocated linearly in the radial direction, a condenser lens provided radially outwardly of the heating element for converging the infrared rays reflected by the mirror, an infrared sensor on which the converged rays impinge, a plate provided between the mirror and the lens and which has a slit therein that is elongate in a direction approximately perpendicular to the surface of the heating element, and an image processor receiving the output of the infrared sensor. The sensitivity is high because infrared rays from around the thermal point of the heating element are blocked by the plate.

Abstract: Device (10) to control the temperature of extruded metallic sections during the step of extrusion from an extrusion press, the device being suitable for connection to, and for governing, a system that controls and regulates the extrusion speed, and being positioned in the vicinity of the outlet of the extruded product from the extrusion die and comprising a carriage (13) able to move circumferentially at least partly about the extruded product (12) on a plane substantially normal to the axis of the extruded product and bearing an optical-fiber (17) monitor (15) connected to a remotely located pyrometer (18).

Abstract: An apparatus for measuring the temperature of an object placed in a plasma by utilizing radiation includes measuring means for measuring the intensity of radiation from the object and the intensity of plasma light in different directions at the same time. The measuring means includes a first lens for receiving the radiation from the object and the plasma light, a second lens for converting the output beam of the first lens into parallel light rays, a third lens for focusing the parallel light rays, and an interference filter disposed rotatably between the second lens and the third lens.

Abstract: The rotor exhaust gas bulk total temperature relative to the last blade row of a combustion turbine is determined by traversing an optical pyrometer radially across the last stage blades. The resulting radial temperature measurements are then flow weight averaged to provide an accurate bulk gas temperature relative to the last row of blades. Such temperature is useful in a feedback control system for the turbine. A technique of traversing is to cause the optical pyrometer to traverse by mounting its line of sight or optical axis at an angle to its axis of rotation.

Abstract: It is a problem of pyrometric temperature measuring of melts in a vacuum that the material of the melt will be deposited on mirrors, windows and other optical devices so that the radiation will be screened more and more effectively, the closer it comes to the pyrometer. In order to avoid vapor desposition in the path of radiation, a grating arrangement is provided between the melt and the pyrometer, which focusses the incoming radiation and concentrates it onto the pyrometer. The grating arrangement is partly permeable to the molecules of the melt material. The direct path between the melt and the pyrometer is blocked by a screen. In this way, vapor deposition on the window prefixed to the pyrometer are avoided, while the radiation can reach the pyrometer.

Abstract: The temperature and radiant energy emissivity of a semiconductor substrate or wafer undergoing processing are monitored by combining indications derived from an interferometer and the intensity of radiant energy emitted from the substrate. The radiant energy intensity is detected at adjacent maxima or minima in the intensity of the interference pattern.

Abstract: A gas turbine pyrometer filtering method and system uses a pyrometer to measure the high pressure turbine blade temperatures using infrared optical detection techniques. The pyrometer signal can be cluttered by positively biased noise. The turbine speed and the pyrometer electrical signal are alternately sampled by an analog to digital converter, and several revolutions of pyrometer data are stored in the local RAM. A data compression algorithm then selects single samples, at evenly spaced intervals, which results in a given number of revolutions, containing an exact number of data points of aligned data in RAM. This data is passed to a clutter rejection filter which then passes only the lowest value for each of the points in all revolutions of data. Thus, the revolutions of acquired data are reduced into a single revolution of filtered data for the current sampling. This single revolution of filtered data in then enter into a circular queue and the last element is discarded.

Abstract: A coated, embrittlement resistant optical fiber thermometer fiber is disclosed, which can be a sapphire or silica fiber with a metallic coating which prevents the fiber from becoming brittle at high temperature, and enhances transmission of radiation through the fiber. The coating can be applied over a thin "conductive" film attached to the fiber exterior using vacuum metallization, sputtering, or organo-metallic deposition. The coating may comprise pure platinum electroplated over a thin conductive film. The fiber may include a first end terminating in a blackbody radiator in a furnace and a second end terminating at a receptor apparatus. A coated fiber of the present invention provides a hermetic seal around the fiber to prevent its exposure to hydroxyl ions in the atmosphere. Fibers of the invention will remain flexible even after exposure to temperatures well over 1000 degrees Centigrade. The coating also prevents unwanted external radiation from entering the fiber.

Abstract: An interferometer suitable for length measurements, comprising a laser light source, a beam splitter to divide light stemming from the laser light source into a measuring beam and a reference beam, and recombination means at which the reference beam being guided along a reference path and the measuring beam interfere. The measuring beam travels along a measuring path that leads over a movable measuring reflector and partly through a gaseous ambient medium. The interferometer further comprises photodetector means to analyze optical interference signals stemming from the recombination means. At least one static etalon of a known length is provided to determine or compensate for variable environmental conditions (variable refractive index) of the ambient medium. The etalon comprises two reflection surfaces and is illuminated by light stemming from the laser light source. The space lying inbetween these reflection surfaces is filled with the ambient medium.

Abstract: A radiation pyrometer has four rectangular photodiodes mounted in an orthogonal array. Radiation from a hot body is focussed as a circular image centrally of the array. The outputs of diagonally opposite photodiodes are connected together to form two identical output channels.

Abstract: An infrared temperature sensor with a sensor element sensitive for infrared radiation and which generates an analog output signal, permits a speed-variable and resolution-variable infrared temperature measurement, in that at least one resolution-adjustable converter means is provided for converting the analog signal into a digital signal and in that a digital signal processing means is provided for the program-controlled linearization and evaluation of the digital signal.

Abstract: A precious metal blackbody radiator fired on a silica or sapphire fiber is disclosed for use in an optical fiber thermometer. The fiber can be coated or uncoated. If a coated fiber is used, the fiber can be a silica or sapphire fiber, protected with an outer metallic coating, such as platinum, which may be electroplated over a thin electrically conductive film coated on the fiber. The blackbody radiator may be mounted on a first end of the fiber, and the fiber may have a second end terminating at a receptor apparatus. The blackbody may comprise semisolid platinum paste placed on a coated or uncoated fiber, dried, and fired over a flame or in a high-temperature furnace. The firing step causes strong adhesion of the blackbody to the fiber.

Abstract: A temperature sensor comprising a probe, infrared fibers, super-cooled detors and their associated electronics, and a computer for determining the temperature from the output of the electronics. Photons from a heat source are collected by the infrared fibers and transmitted to the detectors where they are amplified by the electronics. A voltage is then outputted which represents measured temperature. The voltage is sampled by the computer where it is converted to temperature by use of computer algorithms.

Abstract: A purging air flow system that causes air to pass over a pyrometer lens or window to keep it clean and free from particulate contaminants has an annular, continuous slot for air inlet around the periphery of the lens to permit flow of air across the lens without any obstructions in the path of flow inwardly from the outer edge of the lens. An asymmetric flow pattern is established across the lens surface, either by having a differential size slot at different peripheral portions of the peripheral edge of the lens or window, or by providing a radial swirl about the axis of the window so that when the air goes through the slot, the tangential velocity creates a moving asymmetric flow pattern on the window surface.

Abstract: An apparatus and method for non-contact temperature measurement of an object, using least-squares-based multiwavelength pyrometry techniques. Radiances from an object are detected by a spectrograph/detector apparatus and are converted into electronic signals readable by a computer. The computer then operates on these signals as data to be curve-fit, using least squares analysis, to a predetermined theoretical function for the dependence of the radiance on the wavelength. When the computer has minimized the least-squares difference function, the computer identified a parameter representing the temperature and reports this value to the user, along with a collaterally calculated maximum error in the temperature estimate.

Abstract: A method for remotely measuring an unknown temperature Ts of a transparent medium by comparison with the known temperature Tr of a transparent reference material consisting of the steps ofcombining the outputs of a continuous-wave (CW) laser and a high intensity pulsed laser to form a combined laser output beam, wherein the high intensity pulse component of the output beam exceeds the intensity required to produce stimulated Brillouin scattering (SBS) in the transparent medium;splitting the combined laser output beam into first and second sub-beams;amplifying the CW components of the first sub-beam to an intensity exceeding the intensity required to produce stimulated Brillouin scattering (SBS) in the reference material while simultaneously suppressing the pulse components in the first sub-beam;directing the first sub-beam with the amplified CW component into the reference material and thereby generating a CW phase-conjugate beam;directing the second sub-beam into the transparent medium and generating a pulse

Abstract: It is a problem of pyrometric temperature measuring of melts in a vacuum that the material of the melt will be deposited on mirrors, windows and other optical devices so that the radiation will be screened more and more effectively, the closer it comes to the pyrometer. In order to avoid vapor deposition in the path of radiation, a grating arrangement is provided between the melt and the pyrometer, which focusses the incoming radiation and concentrates it onto the pyrometer. The grating arrangement is partly permeable to the molecules of the melt material. The direct path between the melt and the pyrometer is blocked by a screen. In this way, vapor deposition on the window prefixed to the pyrometer are avoided, while the radiation can reach the pyrometer.

Abstract: A system for measuring the temperature of a semiconductor wafer 12 comprises a light source 14, a photodetector 20 which is operable to determine light intensity, and a mirror 18 in a predetermined fixed position from a beam splitter 16. The components are positioned such that light from the light source 14 impinges the beam splitter 16 and subsequently reflects off the mirror 18 and the wafer 12 and is received by the photodetector 20. Changes in the temperature of the wafer 12 are calculated based upon changes in the intensity of the received light which depends upon the expansion/contraction of the wafer. The absolute temperature may be calculated based on a known reference temperature and the changes in wafer 12 temperature. A second system and method for measuring the temperature of a semiconductor wafer which includes the use of a plurality of mirrors and two beam splitters is also disclosed.

Abstract: A scanning infrared sensor (10) in which the scanner (21), detector (32) and temperature converter (35) are all contained in proximity with one another in a single housing assembly (18) enables correction of both emissivity based on emissivity settings (41) for each of a plurality of spot targets (16') along a scan line (16) and correction for DC offset errors based on reference temperature measurement (45) of hot and cold references (34, 36). Correction is performed before digital conversion by an A/D converter (56) by a nulling circuit (46), a programmable gain circuit (50) and a bias circuit (62) to produce corrected digital temperature signals on a plurality of output ports (26) respectively associated to a plurality of spot targets (16') along a scan line (16) on a target (12) which are individually connectable with a multiple temperature display (27), a temperature recorder (28) and a process control (30).

Abstract: By controlling the temperature of a glass reservoir tube attached to a closed vapor cell, the vapor pressure inside the cell can be accurately controlled. The apparatus for controlling the reservoir temperature includes an electric heater, a temperature sensor, heat straps to distribute and remove heat from the reservoir, and a clamp to hold the apparatus in close thermal contact with the exterior of the reservoir. An external control circuit energizes the reservoir heater as required. In the preferred embodiment the vapor cell functions as an optical filter when filled with a heated metallic vapor such as cesium. The reservoir tube functions as the cold spot of the cell and contains a small pool of the metal in liquid form.This invention was made with Government support under N66001-86-R-0050 awarded by the Department of the Navy. The Government has certain rights in this invention.

Abstract: Improved thermooptical sensing devices are provided wherein at various predetermined sectons of an optical fiber is juxtaposed a material characterized by a temperature dependent index of refraction. This material forms a temperature sensitive area which controls the transmission of light through the optical fiber thereby allowing detection of temperature changes along the fiber. The materials may be crystalline thermoplastic polymers, modified organic polymers containing inorganic modifiers, polymer systems containing discrete phases of organic polymers and inorganic additives or thermochromic inorganic compounds.

Abstract: The present invention constitutes a pyrometer device and an associated method of operation for measuring temperature based on the radiation emitted by a heated body in which increased accuracy is achieved by actively ascertaining the emittance of the body whose temperature is being measured. The pyrometer device includes a light source for intermittently illuminating the heated body and a radiation sensing mechanism for measuring the amount of light reflected and radiated by the body. The pyrometer device further includes a signal processing unit for processing the information developed by the radiation sensing mechanism and deriving the temperature of the body based on a calculated emittance factor and the amount of light radiated by the body.

Abstract: A technique for measuring the unknown subsurface temperature T of a bulk transparent medium such as sea water by focussing a high intensity pulsed laser beam in a first direction into the water to a predetermined depth D, producing stimulated Brillouin scattering (SBS) in a second direction opposite to the first direction and generating from the SBS stimulated Raman scattering (SRS) in the second direction, analyzing the spectra of the SRS and determining therefrom the temperature T. The depth D is is selected to insure that the entire SBS pulse is in the water.

Abstract: A technique for measuring the unknown subsurface temperature T.sub.s of a bulk transparent medium such as ocean water by splitting a pulsed laser beam having a high intensity into two sub-beams, one of which is a probe beam directed into the medium. The intensity of the output beam pulses exceeds a predetermined threshold sufficient to cause stimulated Brillouin scattering within the medium and to produce therefrom a phase-conjugate beam which propagates along the path of the first sub-beam but in the opposite direction. The second sub-beam combines with the PC beam and the combined beams mix at the cathode of a photodetector thereby producing a heterodyne frequency proportional to the temperature T.sub.s. Converts the heterodyne frequency into a temperature value yields the desired unknown T.sub.s.

Abstract: A technique for measuring the unknown subsurface temperature T.sub.s of a bulk transparent medium such as ocean water by generating a continuous (cw) laser beam and pulsed laser beam both having the same wavelength, with the intensity of the pulsed laser beam exceeding the intensity required to produce stimulated Brillouin scattering in the water. By directing the pulsed laser beam into the water, it causes a return phase-conjugate beam to emanate therefrom. The return phase-conjugate beam and the pulsed laser beam are separated, and the phase-conjugate beam and the cw beam are mixed together thereby producing a heterodyne frequency proportional to the temperature T.sub.s. By converting the heterodyne frequency into a temperature value, yields the desired unknown T.sub.s.

Abstract: A device and method are provided for determining the bulk (average) temperature, surface temperature, temperature profile, and thickness of radiation translucent materials. These material functions are determined by evaluation of the intensity of the radiation emitted from the material using two detectors with a radiation source placed in the optical path of one of the detectors. The data is taken at several intensities of source radiation and reduced to obtain the bulk temperature and material thickness. The second detector is used to measure the surface temperature. These data are then used to determine the temperature profile in the material.

Abstract: Method and apparatus for contactless locally resolved instantaneous measurement of the density and/or temperature of a gas in a measurement volume which can have a relatively large area and a relatively small thickness, wherein by laser radiation two rotational transitions of a molecular constituent of the gas excitation in which the excited state has a life time which is substantially shorter than the reciprocal collision frequency in the gas, and wherein the fluorescence intensity or absorption corresponding to the two rotational transitions is measured. From the measured intensities the density and temperature can be calculated.

Abstract: To remotely measure the unknown subsurface temperature T.sub.s of a bulk transparent medium such as ocean water, a laser beam having a high power or intensity is split into two parts, a probe beam and a reference beam. The probe beam is directed into a sample of ocean water, and the reference beam into a reference sample of water having a known temperature T.sub.r. The intensities of the two beams, which exceed a predetermined threshold are sufficient to cause stimulated Brillouin scattering (SBS) within the two samples and produce therefrom two phase-conjugate beams. The two phase-conjugate beams are mixed to produce a heterodyne frequency that is proportional to the difference in temperature T.sub.s and T.sub.r. The frequency difference is converted into a temperature value equal to the value of T.sub.s.

Abstract: An optical technique for determining surface temperature utilizes the Christiansen effect that is exhibited by dielectric materials; i.e., strong absorption bands at certain wavenumber values, causing the radiance of the material to be that which would characterize a theoretical black body at that wavenumber value.

Abstract: Apparatus for measuring the unknown subsurface temperature T.sub.s of a bulk transparent medium such as ocean water comprises a pulsed laser having a high intensity (power per unit area) output beam split into two sub-beams, one of which is a probe beam directed into the ocean water. The intensity of the output beam pulses exceeds a predetermined threshold sufficient to cause stimulated Brillouin scattering within the medium and to produce therefrom a phase-conjugate beam which propagates along the path of the first sub-beam but in the opposite direction. The second sub-beam is reflected by a mirror to and combines with the PC beam and the combined beams are mixed at the cathode of a photodetector which produces a heterodyne frequency that is proportional to the temperature T.sub.s. A frequency measuring instrument converts the heterodyne frequency into a temperature value equal to T.sub.s.

Abstract: Apparatus is disclosed for remotely sensing the unknown subsurface temperature T.sub.s of a bulk transparent medium, such as ocean water, using a cw laser beam and a pulsed laser beam. In one embodiment the cw output of a continuous laser is split into two sub-beams. An optical amplifier periodically amplifies the first such sub-beam thereby generating an intense pulsed laser beam having a plurality of pulses with the same wavelength as the cw laser beam. The intensity level of the pulses is sufficient to produce stimulated Brillouin scattering when focussed into the ocean water. The pulsed laser beam is directed into the water thereby generating an intense return phase-conjugate beam propagating along the path of the pulsed laser beam but in the opposite direction thereto. The phase-conjugate beam and the second sub-beam are mixed at the cathode of a photodetector to produce a heterodyne frequency proportional to the temperature T.sub.s.

Abstract: To remotely measure the unknown subsurface temperature T.sub.s of a bulk transparent medium such as ocean water, a high intensity pulsed laser beam is split into two sub-beams, a probe beam and a reference beam. The probe beam is directed into a sample of ocean water of unknown temperature, and the reference beam into a reference sample of water having a known temperature T.sub.r. The irradiance of the two pulse beams exceeds a predetermined threshold sufficient to cause stimulated Brillouin scattering (SBS) within the two samples and produce therefrom two return phase-conjugate (PC) beams. A photodetector mixes the two PC beams and produces a heterodyne frequency that is proportional to the difference in temperatures T.sub.s and T.sub.r. A frequency measuring instrument converts the heterodyne frequency into a temperature value equal to T.sub.s.

Abstract: Radiation detectors and method measure the emissivity of a remote, heated semiconductor wafer in the presence of ambient radiation. Incident radiation within a selected waveband from a controlled source intermittently radiates the remote wafer, and reflected radiation therefrom is detected in synchronism with the intermittent incident radiation to yield output indications of emissivity of the wafer under varying processing conditions. The temperature of the wafer is monitored by another radiation detector (or detectors) operating substantially within the same selected waveband, and the temperature indications thus derived are corrected in response to the output indications of emissivity to provide indications of the true temperature of the wafer.

Abstract: The interferometer comprises an emitter arm (10) excited by a source (11) and a receiver arm (20) associated with a photodetector (21) united by an optical coupler (50) so as to form a reference arm (30) and a measurement arm (40) terminating in a sensor (41). The arms (30) and (40) are constituted by one and the same optical fiber whose diopter of its free end (31) acts as a partially transparent mirror for the reference optical wave. This end (31) is coupled to the sensor (41) which returns the measurement optical wave through said diopter. Application in particular in the measurement of temperatures, for example in turbo-machines or of fluctuations of flow density.

Abstract: A catoptric type radiation thermometer having a catoptric type optical system is provided with a light receiving member for receiving an infrared ray emitted from an object to be measured. The infrared ray is periodically prevented and allowed to pass by a shutter blade fixed to an optical chopper supported by a bimorph cell vibrated by an AC signal. The optical chopper is arranged in such a manner that the longitudinal direction thereof is perpendicular to an optical axis of the optical system and the transverse direction is parallel to the axis and that one end of the chopper is supported at the outside of the passageway of the infrared ray.

Abstract: The infrared thermometer optical chopper includes a planar shutter having infrared radiation transmissive and infrared reflective portions arranged on the shutter, and a mechanism for rotating the shutter sequentially through a series of stop positions in which the transmissive and reflective portions are sequentially aligned with the internal optics of the infrared thermometer. A mechanism is also preferably provided for sensing the positioning of the shutter at the stop positions, to determine whether the shutter stop position alignment is in an infrared radiation transmissive phase or in an infrared radiation reflective phase.

Abstract: The invention involves a method for measuring the temperature in a heating system of the type having an electrically heated hot plate with a filled cooking vessel on it and a radiation pick-up located at varying distances from the side of the vessel and pointed at it which emits a signal indicating the temperature of the substance in the vessel based upon radiation from an area on the side of the vessel as detected by the radiation measurement field of the radiation pick-up, the radiation intensity of which decreases as a square of increasing distance. To compensate for the effect on measurements of spurious radiation form the changing position of the vessel on the hot plate, the invention involves adjusting the angle of a non-intersecting radiation measurement field to obtain corresponding reduction in the area of radiation detetion on the vesel for increasing distances between vessel and radiation pick-up.

Abstract: Subsurface waves in an ocean are created by the turbulence in a submarine's wake. These waves can be remotely detected by a search submarine by monitoring subsurface water temperatures using a laser. A pulsed laser beam is directed into the water to at least the depth of the thermocline and an analysis is made of the resultant Brillouin and Rayleigh backscatter components. Wavelength shifted Brillouin scatter is mixed with the unshifted Rayleigh scatter in a self-heterodyne manner for each volume element of illuminated water, and the frequency of the heterodyne signal is measured and converted into equivalent temperature values. This produces the desired temperature-depth profile of the water enabling detection of the first submarine by tracking the internal waves at or near the ocean thermocline.

Abstract: A method for detecting a state of a substance existing in a pipe, the outer surface of which is exposed, which comprises: heating or cooling a pipe, the outer surface of which is exposed, from the side of the outer surface thereof so that a difference in temperature is produced between a portion of the outer surface of the pipe corresponding to a portion of the inner surface thereof, which is in contact with a solid or liquid substance existing in the pipe, and a portion of the outer surface of the pipe corresponding to a portion of the inner surface thereof, which is not in contact with the substance; then shooting the outer surface of the pipe by means of a thermal imaging system while the above-mentioned difference in temperature still remains on the outer surface of the pipe to obtain a thermal image of the difference in temperature; and detecting a state of the substance existing in the pipe by means of the thus obtained thermal image.

Abstract: A temperature measuring apparatus is provided for determining the temperature of a target material to be measured as compared with the temperature of a spaced reference source which has a temperature control for controlling the temperature of the reference source. A differential radiation detector having a first detector exposed to the target material and a second detector which is shielded from the target material and exposed to the reference source provides a differential output or error signal which is used to control the temperature of the reference source. When the reference source temperature is the same as the target, the temperature of the reference source is read out which is the temperature of the target material regardless of the emissivity. The differential radiation detector is positioned in spaced relation to the target material and is focused onto the target and the reference material and the error signal generated is used for controlling the temperature of the reference source.

Abstract: A temperature measuring device for a rotating roll comprises a housing with guide rollers around which a belt is looped and held under tension by an idler roll. One boundary of the housing is arched concavely in accordance with typical roll diameters to enable the blet to run freely in this region outside the housing and press against a roll surface in a looping region to drive the belt as the roll rotates. The inner side of the belt facing away from the roll may be blackened and the energy radiated therefrom may be measured by a radiation pyrometer to determine the temperature of the roll.

Abstract: A method and an apparatus for detecting a defective portion on the inner surface of a pipe, the outer surface of which is exposed, includes: heating or cooling a pipe, the outer surface of which is exposed, from the side of the outer surface thereof so that a difference in temperature is produced between a portion of the outer surface of the pipe corresponding to an accumulation of foreign matters or a thinner portion as a defective portion on the inner surface thereof, and a portion of the outer surface of the pipe corresponding to a normal portion of the inner surface thereof; then shooting the outer surface of the pipe by means of a thermal imaging system while the above-mentioned difference in temperature still remains on the outer surface of the pipe to obtain a thermal image of the difference in temperature; and detecting the accumulation of foreign matters or the thinner portion as the defective portion of the inner surface of the pipe by means of the thus obtained thermal image.

Abstract: Subsurface waves in a body of water such as an ocean caused by a submarine are remotely nonacoustically detected by monitoring subsurface water temperatures using a laser. A pulsed laser beam is directed into the water to at least the depth of the thermocline and an analysis is made of the resultant Brillouin and Rayleigh backscatter components. Wavelength shifted Brillouin scatter is mixed with the unshifted Rayleigh scatter in a self-heterodyne manner for each volume element of illuminated water, and the frequency of the heterodyne signal is measured and converted into temperature. This produces the desired temperature-depth profile of the water enabling detection of internal waves generated by submarines.

Abstract: The subsurface temperature of a body of water such as an ocean is measured remotely by directing a laser beam deeply into the water and analyzing the resultant Brillouin and Rayleigh backscatter components. Wavelength shifted Brillouin scatter is mixed with the unshifted Rayleigh scatter in a self-heterodyne manner for each volume element of illuminated water and the frequency of the heterodyne signal is measured. This produces the desired temperature-depth profile of the water.

Abstract: Laser pyrometer techniques are utilized to accurately image a true temperature distribution on a given target without touching the target and without knowing the localized emissivity of the target. The pyrometer utilizes a very high definition laser beam and photodetector, both having a very narrow focus. The pyrometer is mounted in a mechanism designed to permit the pyrometer to be aimed and focused at precise localized points on the target surface. The pyrometer is swept over the surface area to be imaged, temperature measurements being taken at each point of focus.

Abstract: An optical adapter is installed between a standard lens tube and a television camera for inverting the image and for providing focus and intensity control. The adapter is provided with fittings which mate with both the standard lens tube and the camera. The adapter permits one set of lens tubes to be used with both Vidicon black and white television camera systems and solid-state color television camera systems. A motor mounted on the adapter and controlled by the camera controls an iris, thus permitting automatic intensity control.

Abstract: Semiconductors may be optically tested for their temperatures by illuminating them with tunable monochromatic electromagnetic radiation and observing the light reflected off of them. A transition point will occur when the wavelength of the light corresponds with the actual band gap energy of the semiconductor. At the transition point, the image of the semiconductor will appreciably darken as the light is transmitted through it, rather than being reflected off of it. The wavelength of the light at the transition point corresponds to the actual band gap energy and the actual temperature of the semiconductor.

Abstract: The distributed temperature sensor employs an optical fiber as sensing element located in an ambient or near a body of which the temperature is to be monitored or measured. A source of light pulses sends into the fiber, pulses of predetermined duration. The backscattered radiation is collected for each pulse and the frequency spectrum variations in the backscattered radiation with respect to the incident radiation are analyzed. A computer obtains the temperature from said variations. The source and the spectrum variation analyzer are part of an optical time domain reflectometer which allows the temperature information to be associated with the information on the position of the backscattering point along the fiber.

Abstract: An infrared heat source is directed through a chopper or modulator and beam splitter to the surface of the water. A pair of radiometers are provided, one located behind the back surface of the wafer to measure transmittance, the other adjacent to the beam splitter to measure wafer reflectance. The wafer temperature may then be calculated using an experimentally determined relationship between wafer radiance W.sub.W and wafer temperature, with wafer radiance being provided by the relationship ##EQU1## where r.sub.BS is the reflectance of the beam splitter, W.sub.W is the blackbody radiance of the wafer, W.sub.a is the blackbody radiance equivalent to ambient temperature, and e.sub.W is the wafer emittance. Alternatively, rather than locate a radiometer behind the wafer to measure wafer transmittance, a mirror may be located behind the wafer to reflect the transmitted energy back through the wafer on a periodic basis for a short part of each duty cycle.

Abstract: An optical pyrometer makes a temperature measurement of a remote body that is insensitive to spurious radiation by modulating the temperature of the body of optical irradiation in a first optical wavelength range at a low modulation frequency and synchronous detection of emitted optical radiation in a second optical wavelength range, together with modulation in the second optical wavelength range and detection in the first wavelength range. The measurement so made are combined to form a parameter representative of the body temperature that is insensitive to the environment of the body.