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 method and apparatus for detecting the temperature of gray and non-gray bodies in the presence of interfering radiation. A gray body has a constant emissivity less than 1 and a non-gray body has an emissivity which varies with wavelength. The emissivity and reflectivity of the surface is determined over a range of wavelengths. Spectra are also measured of the extraneous interference radiation source and the surface of the object to be measured in the presence of the extraneous interference radiation source. An auxiliary radiation source is used to determine the reflectivity of the surface and also the emissivity. The measured spectrum of the surfaces in the presence of the extraneous interference radiation source is set equal to the emissivity of the surface multiplied by a Planck function containing a temperature term T plus the surface reflectivity multiplied by the spectrum of the extraneous interference radiation source. The equation is then solved for T to determine the temperature of the surface.

Abstract: A non-contact pyrometric technique is provided for measuring the temperature and/or emissivity of an object that is being heated by electromagnetic radiation within the optical range. The measurement is made at short wavelengths for the best results. The measurement may be made at wavelengths within those of the heating optical radiation, and the resulting potential error from detecting heating radiation reflected from the object is avoided by one of two specific techniques. A first technique utilizes a mirror positioned between the heating lamps and the object, the mirror reflecting a narrow wavelength band of radiation in which the optical pyrometer detector operates. The second technique is to independently measure the a.c. ripple of the heating lamp radiation and subtract the background optical noise from the detected object signal in order to determine temperature and emissivity of the object. Both of these techniques can be combined, if desired.

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: Pyrometer apparatus measures the temperature of a semiconductor wafer which when heated by radiation from a bank of lamps emits thermal radiation which includes radiation contained in a selected spectral band. The apparatus includes a reaction chamber supporting the wafer and disposed above the bank of lamps. A hollow envelope reflecting incident radiation and thermal radiation from the wafer surrounds and is spaced from the chamber and the bank of lamps. A portion of the reflected radiation and the thermal radiation passes upwardly through a first opening. A source of said incident radiation disposed adjacent a second opening produces radiation within said spectral band which enters said envelope and is reflected inside the envelope to illuminate a selected spot on the wafer hemispherically. The spot reflects a portion of the incident radiation upwardly through the first opening.

Abstract: The present invention comprises a method and apparatus for determining actual temperature, reflectivity and fluorescence of a surface and comprises in the preferred embodiment a two-dimensional focal plane array of rapidly tunable infrared detectors, 11, adapted to detect the emitted infrared flux from a surface of interest, 10, across pre-selected spectral segments in the 4-15 .mu.m range. The invention further comprises a computer having deconvolution algorithms, 13, for isolating the effects of reflectivity, fluorescence and environmental factors affecting infrared emission for each pixel of the generated image at various spectral segments in the 4-15 .mu.m range. The device further includes means for generating images of temperature, emissivity and fluorescence for diagnostic use.

Abstract: The apparatus and method permit simultaneous and precise determination of the temperature and spectral emittance, over a wide spectral region, of a hot sample. Radiance, and hemispherical reflectance and transmittance measurements are employed, and FT-IR technology is advantageously applied. Reflectance and (where necessary) transmittance measurements are utilized to determine the fraction of incident radiation, of selected wavelength, that is absorbed by the sample, in turn establishing a spectral emittance value. Taken with the measured radiance at the same wavelength, the spectral emittance value will provide a quantity that can be matched with the spectral radiance of a theoretical black body, again at the selected wavelength, to thereby derive the temperature of the hot sample; this in turn enables determination of the spectral emittance of the sample over a desired spectral range.

Abstract: A method of using infrared light for measuring the temperature of a semiconductor element with a surface layer formed by two kinds of materials that have different emissivities and optical reflectances is disclosed. The method includes the step of taking an image with diffused light reflected from the surface of a semiconductor element by an image taking device.

Abstract: A non-contact pyrometric technique is provided for measuring the temperature and/or emissivity of an object that is being heated by electromagnetic radiation within the optical range. The measurement is made at short wavelengths for the best results. The measurement may be made at wavelengths within those of the heating optical radiation, and the resulting potential error from detecting heating radiation reflected from the object is avoided by one of two specific techniques. A first technique utilizes a mirror positioned between the heating lamps and the object, the mirror reflecting a narrow wavelength band of radiation in which the optical pyrometer detector operates. The second technique is to independently measure the a.c. ripple of the heating lamp radiation and subtract the background optical noise from the detected object signal in order to determine temperature and emissivity of the object. Both of these techniques can be combined, if desired.

Abstract: A method of measuring the temperature of a remote body which comprises determining the frequency range to be covered and the portion of that range or frequency band to be covered by each detector of a detector array or by a single detector via a filter for applying different frequency bands to the single detector. The required detector or detectors are then provided and sense the energy radiated by the remote body whose temperature is to be measured. The detector or detectors then provide an output of the amount of energy measured in each unique frequency band and sends these measured outputs to a processor. The processor receives the measured outputs from the detector(s) and determines therefrom in accordance with an algorithm thereat the measured temperature. The processor then provides an output indicative of the measured temperature.

Abstract: Apparatus and process for determining the emissivity of a test specimen including an integrated sphere having two concentric walls with a coolant circulating therebetween, and disposed within a chamber which may be under ambient, vacuum or inert gas conditions. A reference sample is disposed within the sphere with a monochromatic light source in optical alignment therewith. A pyrometer is in optical alignment with the test sample for obtaining continuous test sample temperature measurements during a test. An arcuate slit port is provided through the spaced concentric walls of the integrating sphere with a movable monochromatic light source extending through and movable along the arcuate slit port. A detector system extends through the integrating sphere for continuously detecting an integrated signal indicative of all radiation within its field of view, as a function of the emissivity of the test specimen at various temperatures and various angle position of the monochromatic light source.

Abstract: A method for determination of the true temperature T and true radiative emissivity of a body at temperature T, using measurements of total energy radiated by the body in two or more adjacent wave length ranges .lambda..sub.1 .ltoreq..lambda..ltoreq..lambda..sub.2 and .lambda..sub.3 .ltoreq..lambda..ltoreq..lambda..sub.4 ; the wave length ranges may partially overlap or may be adjacent but non-overlapping.

Abstract: Method and apparatus for accurately and instantaneously determining the thermodynamic temperature of remote objects by continuous determination of the emissivity, the reflectivity, and optical constants, as well as the apparent or brightness temperature of the sample with a single instrument. The emissivity measurement is preferably made by a complex polarimeter including a laser that generates polarized light, which is reflected from the sample into a detector system. The detector system includes a beamsplitter, polarization analyzers, and four detectors to measure independently the four Stokes vectors of the reflected radiation. The same detectors, or a separate detector in the same instrument, is used to measure brightness temperature. Thus, the instrument is capable of measuring both the change in polarization upon reflection as well as the degree of depolarization and hence diffuseness.

Abstract: A system and method for optically measuring simultaneously the emissivity d temperature of an object and the ambient temperature with a successive determination of values of spectral radiance or spectral radiant intensity in n wavelength bands in the visible and/or infrared radiation bands and with m temperatures of the object, by obtaining m rows of at least n=4 values of spectral radiance or spectral radiant intensity from the measurements of at least m=3 different temperatures of the object, forming from the rows a set of equations with n.multidot.m=12 unknowns and n.multidot.m measured values, expressing through a set of equationsL1.sub.M,.lambda..sbsb.i =t.sub.QST.sbsb.i .multidot.r.sub.i t.sub.i {.epsilon..sub.i .multidot.L.sub.T.sbsb.OBj.sub.,.lambda..sbsb.i +(1-.epsilon..sub.i)(L.sub.T.sbsb.Amb.sub.,.lambda..sbsb. +r.sub.QST.sbsb.i .multidot..OMEGA..sub.Q .multidot.L.sub.T.sbsb.Q1.sub., .lambda..sbsb.i)}L2.sub.M,.lambda..sbsb.i =t.sub.QST.sbsb.i .multidot.r.sub.i t.sub.i {.epsilon..sub.i .multidot.L.

Abstract: A method of and device for contactless measuring of temperature of an object independently of its emissivity in infrared and/or visible range, is based on finding, by means of Planck law of radiation a curve which is the sum of the radiance or radiant intensity of a radiator having temperature and emissivity of the object and the radiance or radiant intensity of a radiator having the temperature of environment, the latter radiation being reflected by the object with the reflectivity .rho.=1-.epsilon. where .epsilon. is the emissivity of the object. The actual temperature of the object is found from the curve which is most similar to the curve of at least two values of radiance or radiant intensity detected from the object, plotted against the wavelengths.

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: In a thermal-environment sensor which detects thermal conditions in an indoor environment based on the surface temperature of a heating element supplied with a thermal quantity, the spectral emissivity of the outer surface of said heating element closely conforming to the spectral emissivity of the surface of the human skin or clothes thereon so as to bring the radiant heat transfer coefficient of the sensor remarkably near that of the human body.

Abstract: The emissivity of camouflage material is determined from the apparent body emperature measured by a radiometer, calibrated to indicate a temperature of a blackbody would emit corresponding to the radiation received therefrom; and the true temperature of the material and the true temperature at an infrared detector of the radiometer of a radiometer. Computation means is provided for calculating emissivity from the so measured temperatures and for displaying the result.

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 method of determining true temperatures of a heated target material by its radiation based on prior knowledge of an emissivity function which describes the relationship between two spectral emissivities for the target material, comprising measuring two radiances corresponding to said two spectral emissivities from the target material, assuming a temperature of the target material, then calculating a pair of emissivities which satisfy the emissivity fuction whereat the assumed temperature is the true temperature of the target material.

Abstract: A pyrometric measurement method and a multi-channel pyrometer for determining the temperature T.sub.o of surfaces with different emissivities by measuring the spectral signal voltages U.sub.j at j=1 to n effective wavelengths. The invention obtains, by infrared measurements at at least two effective wavelengths, information concerning the object temperature and the emissivity relationships actually existing for selected surface materials, such as those which are typical for a user. The spectral signal voltages U.sub.ij are ascertained as a function of the difference U.sub.oj -U.sub.uj for a discrete number i=1 to n of surface materials differing in emissivity and the hypothetically possible spectral voltages U.sub.oij and, from these, the probable object temperature T.sub.o and the probable applicable surface material are determined from the measured spectral signal voltages U.sub.j, using the functional relationship that has been established for each emissivity .epsilon..sub.ij.

Abstract: A method for the contactless measuring of the temperature of objects with a hanging proportion of differently emitting surfaces having the same temperature by means of a multi-channel pyrometer, for example, for pyrometric measurements, on which there are different amounts of residues of the material to be processed. The spectral signal voltages U.sub.ij are ascertained as a function of the difference U.sub.oj -U.sub.uj for the i=1 to m surfaces of the object differing in emissivity, at least m spectral signal voltages U.sub.j are measured and the object temperature is determined from the additive superimposition of the m radiation sources in the measurement location.

Abstract: A laser materials processing system for computing a real time cooling rate experienced on a workpiece and responsively controlling the operation of a materials processing laser. An image of a point of laser beam-material interaction is transmitted via imaging optical fibers to ratio pyrometer apparatus which provides temperature proportional signals. The temperature signals are used to compute cooling rate.

Abstract: In a thermal-environment sensor which detects thermal conditions in an indoor environment based on the surface temperature of a heating element supplied with a thermal quantity, the spectral emissivity of the outer surface of said heating element closely conforming to the spectral emissivity of the surface of the human skin or clothes thereon so as to bring the radiant heat transfer coefficient of the sensor remarkably near that of the human body.

Abstract: The temperature of a planar material (8) moving down a process path is measured by causing the material to pass through two openings (3,4) made in a waveguide (1) in such a way that the material effectively does not cut the electric field lines present on the walls of the guide (1) and also so the material (8) passes through the guide in a direction generally parallel to the electric field in the propagation mode of the waveguide and through a region of maximum field strength. The temperature of the planar material (8) is determined by measuring the thermal noise emitted by the material (8) as it passes through the slotted waveguide (1). The slots (3,4) for a rectangular waveguide operating in the TE.sub.10 mode are made along the centerline of the two broad sides of the guide.

Abstract: The invention embodies a system and procedure for independently determining the surface emissivity of a mesh membrane material 12. The system is a closed one with respect to unwanted or uncorrected radiation outside the system and is composed of a radiometer 11 connected to a horn antenna 13, a test section 15 sealed to the horn antenna 13 and a cryogenically cooled matched load 17 exposed to the interior of the system. The material 12 is enclosed in a convection test chamber 14 within test section 15, heated within test chamber 14 and allowed to radiate within the system such that a component of the radiation energy of material 12 is measured by the radiometer 11 in terms of brightness temperature. The matched load 17 serves as the stabilizing source of uncorrelated radiation within the system by radiating within the system at a constant cryogenic temperature. The actual physical temperature of the material 12 is also measured during the heating process.

Abstract: A pyrometer for determining the temperature of a surface in the presence of reflected radiation has two infrared radiation sensors, each responsive to different wave length, positioned to receive radiation from the surface. An adjustment factor is developed from sensor response signals when reflected radiation and surface temperatures are the same, and is combined with sensor response characteristics over a range of surface and sensor indicated temperatures to develop a correction factor which when multiplied by the indicated temperature provides the actual surface temperature.

Abstract: A method for continuously measuring the surface temperature of a heated steel strip, includes providing a flat reflecting plate so as to face a heated steel strip at an angle of inclination (.alpha.) with the steel strip. A radiation thermometer measures the amount of heat radiation energy which is emitted from an arbitrary point on the surface of the steel strip and comes directly into the radiation thermometer; and the thermometer also measures the total sum of heat radiation energy which (a) is emitted from a different point on the surface of the steel strip and comes into the radiation thermometer after having been reflected at least twice between the steel strip and the reflecting plate and, (b) is emitted from a final reflecting point, on the steel strip, of the heat radiation from said different point.

Abstract: When a steel sheet or the like is heated in a furnace to a temperature somewhat higher than the room temperature and is still or moved, its temperature can be measured by detecting the radiant energy therefrom. The measurement is normally difficult due to the influence of background noise of radiant energy from the surroundings, change of the transmittance factor of the environment or atmosphere for radiant energy, and change of the emissivity of the object to be measured.

Abstract: A heating apparatus in which an object to be heated placed in its heating chamber can be heated until the surface of the object is charred as desired by the user. A first photo sensor senses the intensity of light of visible spectrum range directed toward and reflected from the surface of the object being heated, and a second photo sensor senses the light intensity related to the light reflected from the surface of the object, that is, at least one of the intensity of illuminating light emitted from a light source and the intensity of illuminating light coming from the exterior of the heating chamber. The degree of charring of the surface of the object is judged on the basis of the output signals from the first and second photo sensors, and the heating operation is controlled on the basis of the result of judgement.

Abstract: A sensor unit comprising two pyrometers arranged in respective chambers disposed side-by-side and open at one end, one chamber being substantially totally reflecting and the other substantially totally absorbing. Periodically, the unit is advanced to the immediate proximity of the product, the signals from the pyrometers are received after the response time of the pyrometers has elapsed, and then the unit is withdrawn to its initial position. The signals from the pyrometers are processed so as to provide a signal representing the emissivity of the product.