Quantum Logic Corporation

Exxon Research and Engineering Company

Exergen Corporation

United States of America As Represented by the Administrator of Nasa

Alexander Stein

Francesco Pompei

Paul Rabinowitz

Bruce N Perry

Andrew Kaldor

Richard Brisk

Asia N Quince

Ira Kasindorf

Barry Kasindorf

There are many industrial applications in which non-contact temperature sensing is useful for increasing production speed and quality, such as printing, laminating, extrusion, and metal forming. Disclosed is a non-contact temperature determining apparatus which uses two wide wavelength bands integrating sensors to determine the radiance ratio of a target and thereby determine a corresponding temperature of the target. Also disclosed is a non-contact temperature determining apparatus in which a beam splitter passes one wide wavelength band to a sensor and reflects another distinct wide wavelength band to another sensor from which temperature can be determined. A disclosed embodiment of the dual waveband temperature detector improves upon traditional and currently available ratio pyrometers by further reducing the cost of the system, making installation and use easier, and improving temperature detection for low temperature industrial applications.

Dual waveband temperature detector

A non-contact pyrometer and method for calibrating the same are provided. The pyrometer includes a radiation sensor configured to measure at least a portion of a radiance signal emitted from a target medium and output a voltage that is a function of an average of the absorbed radiance signal, and an optical window disposed proximate the radiation sensor and configured to control a wavelength range of the radiance signal that reaches the radiation sensor. The pyrometer may further include a reflective enclosure configured to receive the target medium therein, wherein the radiation sensor and the optical window are disposed within the reflective enclosure, an amplifier in communication with an output of the radiation sensor, and a data acquisition system in communication with an output of the amplifier.

Pyrometer

Apparatus for measuring the temperature of an electrically heated pot which uses the Planck formula and employs an infrared reflective hemisphere; first and second infrared wave guides, and first and second infrared filters and infrared detectors as well as a calculating device.

Range pyrometer

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. These stored measurements in the computer are used to calculate the temperature of the target.

Method for remotely measuring temperatures which utilizes a two

Apparatus adapted for use in measuring emissivity of a semiconductor wafer having a radiant energy reflecting surface includes a hollow integrating sphere having first and second spaced apart openings and having an inner surface upon which radiant energy can be distributed. The wafer is disposed with its reflecting surface adjacent the second opening. A first radiant energy detector is disposed on the inner surface of the sphere to detect the distributed energy. First means directs a beam of radiant energy through the first opening in the sphere in such manner that the beam passes through the sphere and the second opening to strike the wafer reflecting surface and is thereupon reflected into the sphere, the reflected energy being distributed upon the inner surface of the sphere and being detected by said first detector. Second means coupled to said first detector and responsive to its detected energy derives therefrom a first electrical signal proportional to the energy reflected from the reflecting surface of said wafer,

Apparatus for measuring the emissivity of a semiconductor wafer

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. A device disposed outside of said envelope adjacent and above the first opening in the path of the reflected portion of incident radiation and said upward portion of wafer thermal radiation and responds within said spectral band to both of said portions to produce a first electrical signal proportional to the said reflected portion of incident radiation and a second electrical signal proportional to said upward portion of wafer thermal radiation. Another device responds to the first and second electrical signals to calculate the temperature of the wafer.

Pyrometer apparatus for use in rapid thermal processing of semiconductor

Apparatus for measuring the value of the directional spectral hemispherical reflectance of the surface of a target when not engaging but being spaced from the target employs a hollow elongated member having a longitudinal axis and first and second opposite ends. The area of the first end is relatively large relative to that of the second end. The first end is open. The member has an inner chamber extending between the ends and has an inner surface adapted to reflect light falling within a specified wave band. The member when the apparatus is in use is positioned with the first end adjacent but spaced from a selected portion of the surface of the target. The longitudinal axis is oriented essentially normal to a region on the selected surface which would be engaged by a line coincident with the axis and sufficiently extended outwardly from the first end. A beam of light falling within said band is directed within at least a portion of the chamber along the axis and outward through the first end to impinge upon the selected surface portion. A portion of the beam is reflected after said impingement backward through the first end into the chamber. The reflected light which strikes the inner surface of the chamber is directed backwardly within the chamber toward the second end. An electrical signal derived from at least a portion of the backwardly directed light provides a measurement of said reflectance value.

Reflectance probe

The temperature of a thermally emitting target which radiates over a band of wavelengths which includes first and second spaced wavelengths and which has an unknown emissivity characteristic at which the emissivity at one wavelength may but does not necessarily differ from the emissivity of another wavelength is read remotely by [a] deriving signals from those portions of the thermal radiation at these two wavelengths; [b] deriving signals from the reflected portions of two beams of radiation at these wavelengths which strike the target; and [c] by using these derived signals to compute the temperature.

Apparatus for remote measurement of temperatures

A pyrometer adapted to be disposed remotely from a heated diffusely reflecting target obtains a first electrical signal from that portion of target radiance which reaches the instrument. A laser beam is generated within the instrument and is directed upon the target, a portion of the beam being reflected back to the instrument. A second signal is obtain from this portion. The separation between target and instrument is measured and a third signal depending on the separation is produced. A fourth signal dependent upon the power level of the beam is produced. The instrument then computes from these signals the surface temperature of the target.

Pyrometer #2

A pyrometer adapted to be disposed remotely from a heated target employs a manually operated optical range finding device for measuring the distance between the target and the pyrometer. The device includes an objective lens mounted in a rotation-type focusing mechanism, split image effect prisms and a viewing screen. A split image appears on the screen when viewing until the mechanism is rotated to a unique angular position at which the image split disappears, the unique focusing position being a monotonic function of the distance. A mechanical gearing arrangement responsive to mechanism rotation is connected to a multi-turn potentiometer having oppositely disposed fixed contacts at each end and a movable contact. The movable contact is moved along the potentiometer in accordance with rotation of the mechanism. For each unique focusing position of the lens there is a corresponding unique position of the movable contact with respect to the end contacts.

Pyrometer 1

The invention teaches a method for measuring the temperature of remote hot samples in the presence of ambient radiation. A portion of the surface of the sample is treated to obtain a spectral emissivity different from the untreated surface. The spectral radiances of the treated and untreated surface portions are measured and the temperature calculated from these values and the known emissivities.

Pyrometer measurements in the presence of intense ambient radiation

A system is disclosed for monitoring the concentration of gaseous ammonia in flue gases by simultaneously measuring the temperature and optical transmission of a flue gas-ammonia mixture.

System for monitoring trace gaseous ammonia concentration in flue gases

The present invention is a system and method for remotely measuring the temperature of hot gases in fired furnaces. This is achieved by adjusting the physical temperature of a black body until it equals the radiation temperature of the black body as determined by a pyrometer viewing the black body through the hot gases.

Pyrometric gas temperature measurement system

The present invention teaches a unique laser radiometer capable of accurately measuring the radiation temperature of a radiant surface and independently measuring the surface's emissivity. A narrow-band radiometer is combined with a laser reflectometer to measure concurrently radiance and emissivity of a remote, hot surface. Together, radiance and emissivity yield the true surface temperature of the remote target. A narrow receiver bandwidth is attained by one of two methods; (a) heterodyne detection or (b) optical filtering. A direct measurement of emissivity is used to adjust the value obtained for the thermal radiation signal to substantially enhance the accuracy of the temperature measurement for a given subject surface. The technique provides substantially high detection sensitivity over a very narrow spectral bandwidth.

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Secaucus, NJ, United States of America

Alexander Stein