Abstract: A cutting tool shim is to be disposed between a cutting insert and a holder and to be fixed to the holder. The ridgeline between the flank face and the rake face forms a cutting edge. The cutting edge includes an arc-shaped portion. A coolant supply path for jetting coolant to the arc-shaped portion is provided in the cutting tool shim, the coolant being supplied from the holder. The coolant supply path includes a lead-in port for leading the coolant from the holder to the coolant supply path, and a jetting port for arc-shaped portion for jetting the coolant to the arc-shaped portion. The jetting port for arc-shaped portion has a curved shape along the arc-shaped portion. The distance between the jetting port for arc-shaped portion and the arc-shaped portion is not less than 2.2 mm and not more than 8.1 mm.

Abstract: Accurate temperature measurement during manufacturing a vitreous silica crucible is enabled. The present invention provides an apparatus for manufacturing a vitreous silica crucible including: a mold for forming a silica powder layer by supplying silica powder therein; an are discharge unit having carbon electrodes and a power supply unit and for heating and fusing the silica powder layer by arc discharge; and a temperature measurement unit for measuring temperature of a fused portion in the mold, wherein the temperature measurement unit is an radiation thermometer for measuring temperature by detecting radiation energy of a wavelength of 4.8 to 5.2 ?m.

Abstract: A pyrometer that is adapted for detecting radiation in the range of 250 to 450 nm is disclosed. The pyrometer can be used for determining the temperature of a matter thermally emitting only ultraviolet-radiation. In particular, the pyrometer can include: a detector having an active area adapted for measuring thermal radiation, a longpass filter having a cut-off wavelength in the range of 400 to 450 nm, means adapted for alternately activating and deactivating the longpass filter, means adapted for measuring a first thermal radiation signal when the longpass filter is deactivated and adapted for measuring a second thermal radiation signal when the longpass filter is activated, and means adapted for determining a temperature corresponding to the measured thermal radiation from a difference of the first radiation signal and the second radiation signal.

Abstract: To avoid an influence on measurement accuracy in a case where an observation window for a measurement sample is provided to a thermal analysis apparatus, the influence being imposed by thermal conduction through the observation window, the observation window is formed of layers of transparent members, and a gap layer is provided between the layers, to thereby reduce the thermal conduction. Gas or solid having a high heat insulation property is employed for the gap layer to further enhance a heat insulation property of the observation window. Accordingly, a change due to heating of the measurement sample is visually observed in the thermal analysis apparatus, to thereby obtain a thermal change or a physical change with higher accuracy.

Abstract: A system and method for determining the temperature of an object without physically contacting the object. The method involves reading a spectral radiation of the object over a plurality of wavelengths to obtain a set of radiation data related to a temperature of the object. A known characteristic of a black body is determined at a plurality of predetermined, different test temperatures. The spectral data and the characteristic of the black body at the various test temperatures are used to calculate a temperature of the object.

Abstract: A differential temperature sensor system and method of determining a temperature shift of an optical resonator and its surroundings are provided. The differential temperature sensor system includes a light generating device capable of generating a beam having a carrier frequency, a modulator capable of modulating the beam with a sideband frequency, and an optical resonator capable of supporting an ordinary mode and an extraordinary mode. The system includes an ordinary mode-lock setup capable of locking the carrier frequency of the beam to the ordinary mode of the optical resonator and an extraordinary mode-lock setup capable of locking the sideband frequency of the beam to the extraordinary mode of the optical resonator by providing a specific radio frequency to the modulator substantially corresponding to a frequency shift between the ordinary mode and the extraordinary mode of the optical resonator resulting from a temperature change of the optical resonator.

Abstract: There is a problem that a delay is caused in signal processing by exercising control so as to cause amplitude peaks in a transmission signal to fall in a prescribed range. A transmission apparatus for conducting wireless communication makes a decision whether a specific pattern which causes a peak exceeding a predetermined amplitude range to be generated in frequency characteristics of a transmission signal is included in a transmission code sequence for forming the transmission signal. And the transmission apparatus selects filter coefficients which prescribe a band limiting factor for the frequency characteristics of the transmission signal, on the basis of a result of the decision, and conducts filtering on the transmission code sequence by using the selected filter coefficients.

Abstract: Disclosed are a temperature measurement apparatus and method for measuring temperature by using RF signals having different frequencies. The temperature measurement apparatus includes a parameter generation unit for generating a first parameter based on a radio frequency (RF) signal having a first frequency and a second parameter based on an RF signal having a second frequency; a parameter detection unit for detecting the generated first and second parameters; and a control unit for calculating a temperature value based on the detected first and second parameters. Accordingly, the temperature measurement apparatus can measure temperature by use of existing components and received RF signals without any addition of a temperature sensor, as well as measure temperature precisely without having any influence on the intensities of RF signals that can vary due to the changes of transmission distances and signal-receiving environments.

Abstract: The temperature of the surface and/or inside of a substrate is measured by irradiating the front surface or rear surface of the substrate, whose temperature is to be measured, with light and measuring the interference of a reflected light from the substrate and a reference light. A method and apparatus for measuring temperature or thickness which is suitable for directly measuring the temperature of the outermost surface layer of a substrate, and an apparatus for treating a substrate for an electronic device, which uses such method, are provided.

Abstract: Remote sensing of the temperature of a greybody or blackbody radiator is effected by passing its radiation (24) through a modulated infrared filter spectrometer. The infrared filter comprises, in sequence, a band pass filter (20), a first polariser (21) which polarises the radiation, an electro-optical element (22) which splits the polarised radiation into two orthogonally polarised components, and a second polariser (23). A lens (28) images the radiation leaving the second polariser onto a detector (27). The electrical signal from the detector (27) is input to a numerical analyser. The electro-optical element (22), typically comprising a birefringent crystal assembly (25) and a birefringent trim plate (26), is configured so that the net optical delay of the orthogonally polarised components passed through it is such that the recombined components are at or near a peak or trough in their interferogram.

Abstract: Method and apparatus for measuring a surface temperature of an object body, by calculating a temperature at each picture element of an image of the object body, on the basis of a radiant intensity ratio at each pair of corresponding picture elements of a first and a second image which are obtained with respective radiations having respective first and second wavelengths which are selected from a light emitted from the surface of the body, by a first filter which permits transmission therethrough a radiation having the first wavelength which is selected according to a radiant intensity curve corresponding to a wavelength of a black body at a lower limit of a temperature measurement range, and which is within a high radiant intensity range in which the radiant intensity is higher than a radiant intensity at a normal room temperature, and a second filter which permits transmission therethrough a radiation having the second wavelength which is selected within the high radiant intensity range, such that the second

Abstract: A method of measuring a temperature of an object body in an electric furnace, based on an intensity of a radiant energy emitted from the object body, the electric furnace being provided with an electric heater operable by application of a drive voltage thereto to heat the object body, the method comprising: a radiant-energy detecting step of detecting an intensity of a radiant energy emitted from the object body; a stray-light noise eliminating step of determining as a noise an intensity of a radiant energy of a stray light which is emitted from an inner wall surface of the electric furnace toward the object body and reflected by a surface of the object body, according to a predetermined relationship between the intensity of the radiant energy of the stray light and the drive voltage applied to the electric heater and based on an actually applied value of the drive voltage, and subtracting the intensity of the radiant energy of the stray light determined as the noise, from the detected intensity of the radian

Abstract: A method and device for photothermal imaging tiny metal particles which are immersed in a given medium like a living cell deposited onto a transparent glass slide. The given medium and immersed tiny metal particles are illuminated through separate phase reference laser beam and sensitive probe laser beam, with the sensitive probe laser beam including a heating laser beam undergoing through impingement on the given medium slight phase changes induced by photothermal effect due to a local heating, in the absence of any substantial phase changes to the phase reference laser beam. Illuminating is performed by focusing the separate phase reference and sensitive probe laser beam through the transparent glass slide at a given depth within the given medium and a transmitted phase reference laser beam and a transmitted sensitive probe laser beam undergoing the slight phase changes are generated.

Abstract: The invention provides a passive two-stage multiwavelength approach for measuring temperature, emissivity and stray-light levels.

Abstract: A method for high temperature process control in which the surface emission intensity of a surface is measured at two near-infrared wavelengths over an array of points covering a fill field of view. The emissivity variable is removed from the temperature calculation and the surface emission intensity measurements are digitally processed, resulting in generation of a color temperature map. The color temperature map is processed in a thermal imaging control algorithm process, producing control output signals, which are then input to a temperature control means for controlling the surface temperature. The apparatus used in carrying out this method is surface temperature monitoring system which includes a multiple-wavelength, near-infrared thermal imaging system.

Abstract: A life estimation device which numerically measures the damage to a machine such as an engine accurately to estimate, the life of the machine accurately without requiring skill. A load map (B) of the two-dimensional distribution of the operation parameters of an engine is made. In accordance with the weighted integration time &agr;i·ki at each level (Bi) of the load map (B), the actual damage &dgr;=&Sgr;&agr;i·ki to the engine for a certain lapse of time &tgr; is calculated. By operating the engine beforehand, a correspondence relation L2 between the magnitude of the damage &dgr; and the life H is predetermined. The life H1 corresponding to the calculated actual damage &dgr;1 is determined in accordance with the predetermined correspondence relation L2 and the H1 is outputted as the estimated life of the engine.

Abstract: Method and apparatus for measuring a surface temperature of an object body, by calculating a temperature at each picture element of an image of the object body, on the basis of a radiant intensity ratio at each pair of corresponding picture elements of a first and a second image which are obtained with respective radiations having respective first and second wavelengths which are selected from a light emitted from the surface of the body, by a first filter which permits transmission therethrough a radiation having the first wavelength which is selected according to a radiant intensity curve corresponding to a wavelength of a black body at a lower limit of a temperature measurement range, and which is within a high radiant intensity range in which the radiant intensity is higher than a radiant intensity at a normal room temperature, and a second filter which permits transmission therethrough a radiation having the second wavelength which is selected within the high radiant intensity range, such that the second

Abstract: A pyrometer for measuring the temperature of an object with high accuracy and fast response time that uses both multi-wavelength pyrometry techniques and nanotechnology. Radiance from an object is transmitted through a fiber optic cable, is received by a thin-film multi-wavelength modulator, and is detected by an optical detector array. More specifically, the pyrometer includes means for conveying light; an optical lens; an optical fiber; means for optically modulating the wavelength of light; means for optically detecting the modulated light; means for transforming the optically detected wavelengths into electrical signals; and means for processing and recording the electrical signals. The means for optically modulating the wavelength includes at least one piezoelectric film deposited by an electrostatic self-assembly method.

Abstract: A method and apparatus for active pyrometric measurement of the temperature of a body whose emissivity varies with wavelength. The emissivity is inferred from reflectivity measured at two wavelengths in an irradiation wavelength band and extrapolated to a wavelength in an emission wavelength band. The extrapolated emissivity is used to correct a blackbody estimate of the temperature of the body in the emission wavelength band. The extrapolation, being temperature-dependent, is done iteratively. Both reflectivity and emission measurements are performed via a common optical head that is shaped, and is positioned relative to the body, so that the optical head has a sufficiently large solid angle of acceptance that the measured temperature is independent of superficial roughness of the body.

Abstract: A method and system for calibrating radiation sensing devices, such as pyrometers, in thermal processing chambers are disclosed. The system includes a reflective device positioned opposite the radiation sensing devices and a calibrating light source which emits light energy onto the reflective device. The system is designed so that each radiation sensing device is exposed to the same intensity of light being reflected off the reflective device, which has a preset value. The radiation sensing devices are then used to measure the amount of light energy being reflected which is then compared to the preset value for making any necessary adjustments.

Abstract: A temperature sensor for measuring a temperature of a substrate in a thermal processing chamber is described. The chamber includes a reflector forming a reflecting cavity with a substrate when the substrate is positioned in the chamber. The temperature sensor includes a probe having an input end positioned to receive radiation from the reflecting cavity, and a detector optically coupled to an output end of the probe. The radiation entering the probe includes reflected radiation and non-reflected radiation. The detector measures an intensity of a first portion of the radiation entering the probe to generate a first intensity signal and measures an intensity of a second portion of the radiation entering the probe to generate a second intensity signal. The detector is configured so that a ratio of the reflected radiation to the non-reflected radiation is higher in the first portion than the second portion. The two intensity signals are used to calculate the temperature and emissivity of the substrate.

Abstract: A thermopile radiation detector (10) has an optical filter layer (16) that supports a thermopile detector (22) and, in addition, filters undesired wavelengths. The filtering is accomplished by selectively absorbing electromagnetic radiation at predetermined wavelengths. The use of the thermopile radiation detector simplifies the overall construction of a system that incorporates the detector by eliminating one focal point in the optical system. By altering the filter material, the number of layers of filter material, etc., a plurality of detectors can be constructed, each responsive to a different wavelength. In forming the detector, the filter can be deposited on a thin backing material such as aluminum. Examples of suitable filter materials include alternating layers of zinc selenide/magnesium fluoride or germanium/magnesium fluoride. After the filter is deposited, the backing is etched away and suitable thermocouples, such as bismuth/antimony, are deposited on one side of the filter.

Abstract: The subject invention relates to a technique employing a calibrated thermal radiometer, and the radiation characteristics of ionic crystals to measure the temperature distribution of crystals during crystal growth. When in high temperature, the ionic crystals often exhibit a transparent region having low reflectance, and low absorption in the spectrum between the short-wavelength absorption edge and the long-wavelength absorption edge. In addition, these crystals have an opaque spectral region having low reflectance and high absorption, i.e. have surface radiation of high emissivity when the spectrum is in the range between the long-wavelength absorption edge and the onset of the Reststrahlen band. The spectral emissivity of the ionic crystal may not change significantly with a variation of temperature in this opaque region.

Abstract: An improved ratio type infrared thermometer utilizes integrating amplifiers for each waveband having the integration time automatically set so that the output voltage utilizes the full range of an analog to digital convertor. The gain and offset of the amplifiers is not ambient temperature dependent so accurate digital representations of the signal for each waveband are provided. The linearized output of each detector is optionally provided so that special or proprietary algorithms for computing the temperature of colored objects can be utilized. A special feature for downloading of updated new programs utilizes a "programming jumper" and an attenuation warning signal is provided for selected levels of attenuation.

Abstract: A system (10) for simultaneously measuring temperature and CO, CO.sub.2 and HC gas content of vehicle (11) exhaust detects and analyzes a beam of infrared electromagnetic radiation (21) projected through a plume (13) of vehicle exhaust to assess the concentration of CO, CO.sub.2, and HC in the vehicle exhaust and detects and analyzes infrared electromagnetic radiation (15) emitted by the plume (13) to assess the temperature of the plume (13) and, consequently, whether the vehicle's (11) catalytic converter is operating in the cold or hot mode. Essentially simultaneous measurement is taken by intermittently interrupting the beam (21) of projected infrared electromagnetic radiation and detecting and analyzing the emitted infrared radiation (15) during the intervals of interruption when the beam (21) is not projected through the plume (13). Intermittent projection of the beam (21) is accomplished by insertion of a chopper wheel (22) between an infrared beam projector (20) and the plume (13).

Abstract: The present invention relates to a totally novel device and process useful for the measurement of the temperature of a radiating body. More particularly, the present invention relates to a device that enhances the resolution and repeatability of the measured temperature of the radiating body by fitting a mathematical correlation to the emitted radiation spectra, generating calculated radiation intensities at specified wavelengths using the mathematical correlation, and then generating a suite of individual two-wavelength temperature values, which can be statistically evaluated and averaged for a final, measured temperature.

Abstract: Thermal, optical, physical and chemical characteristics of a substrate (11) surface are determined with non-contact optical techniques that include illuminating (23) the surface with radiation having a ripple intensity characteristic (51), and then measuring the combined intensities (53) of that radiation after modification by the substrate surface and radiation emitted from the surface. Precise determinations of emissivity, reflectivity, temperature, changing surface composition, the existence of any layer formed on the surface and its thickness are all possible from this measurement. They may be made in situ and substantially in real time, thus allowing the measurement to control (39, 41) various processes of treating a substrate surface. This has significant applicability to semiconductor wafer processing and metal processing.

Abstract: The output stability of an infrared thermocouple is improved by filtering the radiation received by the infrared thermocouple to pass only short wavelengths. The stability is further increased by providing a second infrared thermocouple having its input filtered to pass long wavelengths. The two outputs are combined to obtain an output signal which is substantially independent of emissivity. The linear range of an infrared detector through which its output closely follows that of a linear thermocouple is increased by a calibration method in which an initial offset is provided to a readout device. Calibration of the infrared detector is completed using an adjustable potentiometer. By providing removable apertures, the temperature range through which an infrared thermocouple may be used is extended. Elongated targets are efficiently viewed by an infrared thermocouple having an elongated thermopile flake and an imaging lens.

Abstract: A method and apparatus for measuring a true temperature using a consumable optical fiber, wherein received light emitted from a high temperature liquid is divided into two light beams through a branching filter. A light of a first wave band from a first light beam of the two light beams is detected by a first radiation thermometer, and the light of the first wave band is converted into temperature to output a first temperature. A light of a second wave band from a second light beam of the two light beams is detected by a second radiation thermometer, and the light of the second wave band is converted into temperature to output a second temperature.

Abstract: A method for remotely measuring the temperature of a target maintained at a first relatively low temperature while at the same time the target is heated by thermal radiation from a source spaced from the target and maintained at a second relatively high temperature which employs a two wavelength radiometer and a computer. First and second wavelengths are selected for use. The second wavelength is shorter than the first wavelength, both source and target exhibiting appreciable radiation at the first wavelength, the source emitting appreciable radiation while the target emits essentially no radiation at the second wavelength. The radiation of the source at the first wavelength and at the second wavelength are measured. These two source radiation measurements are stored in the computer. The radiation of the target at the first wavelength and at the second wavelength are measured. These two target radiation measurements are stored in the computer.

Abstract: Self calibrating a pyrometer includes taking two different temperatures thereby generating two voltage spectra, calculating the spectra ratio R of the two voltage spectra, determining the slope of the plot of the logarithm of the spectrum ratio versus c.sub.2 /.lambda. to arrive at a relationship between T.sub.1 and T.sub.2, solving for T.sub.1 within the spectra ratio, and arriving at a value for T.sub.2 by substituting experimentally measured values for R into the spectra ratio equation. This method is then repeated for the determination of T.sub.2. The pyrometer calibration constant h.sub..lambda. can then be determined by dividing the measured voltage spectra by the planck function at the known temperature (i.e., T.sub.1 or T.sub.2). Measurement of subsequent temperatures can now be determined by measuring the voltage spectra and dividing by the calibration constant h.sub..lambda. which will result in a planck function L.sub..lambda. (T) which can be solved to yield the surface temperature.

Abstract: A temperature measurement system for use in a thin film deposition system is based on optical pyrometry on the backside of the deposition substrate. The backside of the deposition substrate is viewed through a channel formed in the susceptor of the deposition system. Radiation from the backside of the deposition substrate passes through an infrared window and to an infrared detector. The signal output by the infrared detector is coupled to electronics for calculating the temperature of the deposition substrate in accordance with blackbody radiation equations. A tube-like lightguide shields the infrared detector from background radiation produced by the heated susceptor.

Abstract: A bichromatic pyrometer for detecting the high temperature of a surface element of an object comprises two photodiodes (18, 19) receiving radiation from the object, each of the photodiodes having a large forbidden band and being sensitive to radiation in a given range of wavelengths, said sensitivity ranges being different and being situated in the visible or near visible regions of the spectrum, said ranges being obtained by selecting the value of the forbidden band of the material constituting each of the photodiodes (18) and (19), said forbidden band being greater than or equal to that of silicon (.gtoreq.1.11 eV). The pyrometer is capable of measuring rapidly changing surface temperatures with great accuracy.

Abstract: Thermal, optical, physical and chemical characteristics of a substrate (11) surface are determined with non-contact optical techniques that include illuminating (23) the surface with radiation having a ripple intensity characteristic (51), and then measuring the combined intensities (53) of that radiation after modification by the substrate surface and radiation emitted from the surface. Precise determinations of emissivity, reflectivity, temperature, changing surface composition, the existence of any layer formed on the surface and its thickness are all possible from this measurement. They may be made in situ and substantially in real time, thus allowing the measurement to control (39, 41) various processes of treating a substrate surface. This has significant applicability to semiconductor wafer processing and metal processing.

Abstract: A thermal condition sensor system monitors equipment such as aircraft engines. The thermal condition sensor system includes a collector which collects radiation from the equipment and a detector assembly which detects collected radiation over a discriminating spectral band region in at least three spectral bands and generates signals representative of detected radiation in each spectral band. A processor receives the signals and generates a report of the thermal conditions of the equipment using interband comparison of the at least three spectral bands.

Abstract: Temperatures along the surfaces of water tubes in an operating steam boiler are determined by detecting infrared radiation emitted from the tube surfaces in one or more narrow pass-bands founds to be available despite the presence of hot and turbulent flue gases between the sensor and the tube surface to be measured.

Abstract: A method for sensing the temperature of a remote object within a chamber that is heated from outside the chamber, includes sensing radiation from the object within the chamber through a window in the wall of the chamber that exhibits different transmissivity than the wall of the chamber to radiation in a selected waveband relative to the waveband of the radiation supplied through the wall of the chamber to heat the object within the chamber.

Abstract: An apparatus and method for remotely measuring emissivity and hence temperature of a surface of an object. The apparatus includes a detector having a radiation receptor for measuring infra-red radiation, an integrating cavity surrounding the receptor for receiving radiation from a surface facing the cavity and delivering the radiation to the receptor, at least two sources of infra-red containing radiation (e.g. light from an incandescent lamp) within the integrating cavity positioned to produce separate beams of the radiation which strike the surface at different angles suitable for reflection to the receptor, and a processor for determining the temperature of the surface from the radiation measured by the detecting means. The use of at least two mutually angled radiation beams compensates for surface anisotropy of the surface whose temperature is to be measured.

Abstract: A pyrometer system for use in measuring the temperature of components in an operating jet engine corrects for random interference in the pyrometer temperature signal caused by radiation from the combustor flame. An optical beam from a periodically moving target engine component such as a turbine blade is provided to a detector module which splits the beam into two beams, one of which has a spectral width less than that of the target beam. Temperature signals are generated by a multiple spectral area pyrometer which are provided to a signal processor for correction. The signal processor compares present target temperature signal values sampled at selected phases during the target period with corresponding ones taken in an earlier period. Previous signals are averaged or replaced with current values if these meet criteria involving one or two temperature signals, noise band and magnitude.

Abstract: A narrow-band pyrometric system measures the temperature of an object (1), such as a semiconductor wafer (1), that is coated with a film (2) having an absorption band. The thermal radiation emitted by the coated object (1) passes through a lens (3) and aperture (4), and then a filter (5). The passband of this filter (5) falls within the absorption band of the film (2). The transmitted radiation is then collected by the radiation detector (6), which measures the intensity. The detected radiation is at a wavelength where the heated object (1) is substantially opaque, and the effect of uncertainties in the emissivity on the temperature measurement is minimized. Thus, a method is provided to coat the object (1) with a film (2) of material having an absorption band encompassing the filter (5) passband, and a thickness sufficiently great that the object (1) appears opaque when viewed through the filter (5).

Abstract: Dual pyrometric detectors and method measure the temperature of a remote heated object in the presence of ambient radiation. One detector measures emitted radiation from both the remote object and from the environment, and the other detector measures radiation predominantly from the environment alone. The output signals from the two detectors are processed electronically to yield the detected radiation from the remote object alone. The result can then be electronically processed to display the pyrometrically-measured temperature of the remote object.

Abstract: In one embodiment, a system for measuring the temperature of a first object, such as wafer 112, in the presence of a second radiating object, such as a heating lamp 118, is disclosed herein. A heating lamp 118 is provided for heating the wafer 112 for device processing. Both the wafer 112 and the lamp 118 emit radiation. A first detector 120 detects radiation emitted by both the wafer 112 and the lamp 118. A second detector 122 which detects radiation from only the heating lamp 118 may also be used. A modulation source 126 is provided for modulating the heater 118 to a selected modulation depth M.sub.L such that the temperature of the lamp 118 varies with the selected AC modulation and the temperature of the wafer 112 remains substantially constant. Also, circuitry is provided for determining the fraction of radiation emitted by the lamp and collected by the first detector 120 (lamp interference signal) based upon the heating lamp modulation and then calculating the precise temperature of the wafer 112.

Abstract: Apparatus for optically determining the temperature of an object in an environment at elevated temperature provides enhanced measurement accuracy by sensing radiation from the object in two or more different wavebands of radiation. The information derived therefrom is cyclically sampled and processed to provide corrected emissivity of the object. The temperature of the object is accurately determined from the corrected emissivity and sensed radiation therefrom. The apparatus includes a radiation detector for receiving radiation during an interval, an optical filter structure with a plurality of optical filters of different radiation transmissive characteristics, and sampling circuits for receiving the radiation signal from the detector during a selected period within the interval during which radiation is supplied to the detector; wherein the selected period is shorter than the interval, is determined in response to the cyclic operation of the filter structure, and contains the least amlitude gradient.

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: Dual pyrometric detectors and method measure the temperature of a remote heated object in the presence of ambient radiation. One detector measures emitted radiation from both the remote object and from the environment, and the other direction measures radiation predominantly from the environment alone. The output signals from the two detectors are processed electronically to yield the detected radiation from the remote object alone. The result can then be electronically processed to display the pyrometrically-measured temperature of the remote object.

Abstract: A temperature measuring device is disclosed which comprises a light source for emitting light the spectrums of which are constant with respect to time, a photoelectric transducer for sensing the emitted light with a plurality of predetermined different wavelengths to generate electrical outputs for each wavelength, and a microcomputer for computing a ratio based on the outputs generated from the transducer and for generating an output signal representing temperature corresponding to the ratio.

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: An apparatus is described which is capable of producing an image of a smelt bed of inorganic chemicals collected at the bottom of a kraft pulp recovery boiler. The image produced is free of interferences of fume particles and gaseous radiation which have obscured prior attempts to view hot surfaces under such environmental conditions. The apparatus includes an industrial closed circuit video camera fitted with an infrared imaging detector or vidicon tube. An objective lens obtains the image. An optical filter interposed between the lens and the vidicon is a key element of the invention and is selected to reject radiation less than about a micrometer to avoid fume interference. The filter is further selected to reject all but limited ranges of radiation to avoid gaseous species overlying the smelt bed which are strongly emitting and absorbing. As an example, a spectral filter centered at 1.68 micrometers with a band width of 0.07 micrometer is suitable for imaging a kraft recovery smelt bed.