By Thermal Radiation Emitting Device (e.g., Blackbody Cavity) Patents (Class 374/2)
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Publication number: 20030095583Abstract: The verification of accuracy of an IR thermometer is provided at any temperature in the range of −25° C. to +100° C., preferably at the room temperature. The magnetic surface of a thermo-conductive mat of the present invention is applied to any metallic surface in a room. The user waits to give the contact thermometer arranged on the mat time to reach thermal equilibrium, and then aims the beam of the IR thermometer at the black body target on the mat. The reading of the IR thermometer is then compared with the reading of a contact thermometer, which is attached to the mat adjacent to the black body target. The lightweight, portable, low-cost temperature verification mats of the present invention can be used for verification of IR thermometers in different customer environments, such as in industrial environments, and with retail equipment, or home appliances, including ovens and freezers, etc.Type: ApplicationFiled: November 19, 2001Publication date: May 22, 2003Applicant: Cole-Parmer Instrument CompanyInventor: Wilhelm Maccarone
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Publication number: 20030026318Abstract: A device (10) for calibrating tympanic thermometers includes an enclosure (12) which may be heated or cooled depending upon the testing temperature. Within the enclosure (12) there is provided a sealed flask (14) which contains substance (16) which melts at the test temperature (this may be ethylene carbonate, melting point 36.3° C.). Located within the sealed flask (14) is a re-entrant well (18) which provides the blackbody for testing tympanic thermometers and a viewing aperture (20). The well (18) is treated to achieve a high surface emissivity. The device (10) allows the testing of thermometers by measuring the triple point or melting point of the substance (16). As the temperature of the substance (16) is accurately known, so is the temperature in the blackbody cavity (18) and thermometers can be calibrated thereby.Type: ApplicationFiled: June 11, 2002Publication date: February 6, 2003Inventor: Graham Machin
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Patent number: 6467952Abstract: A virtual blackbody radiation system (10) includes a light-emitting unit (1) including an LED driven by a fixed current, a light-receiving unit (2) including a sapphire rod, and an optical unit (3) including lenses (31, 32) for converging light emitted by the light-emitting unit in a convergent light. A cylindrical member (41)included in the optical unit (3)can be moved along the optical axis by a servomotor (42) included in a focus adjusting unit (4) for positional adjustment. The focus of convergent light relative to the light-receiving unit (2) can be adjusted by moving the lens (32) disposed in the cylindrical member (41) along the optical axis relative to the light-receiving unit (2). The intensity of the convergent light on the light-receiving unit (2) can be adjusted to the intensity of predetermined blackbody radiation.Type: GrantFiled: March 16, 2000Date of Patent: October 22, 2002Assignee: Tokyo Electron LimitedInventors: Eisuke Morisaki, Masayuki Kitamura, Nobuaki Takahashi, Takashi Shigeoka
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Patent number: 6447160Abstract: A blackbody cavity having two types of wall surfaces wherein a first type has high emissivity and a second type has low emissivity. The low emissivity wall surface has an aperture from where the infrared radiation escapes the cavity, and is preferably shaped to minimize the escape through the aperture of radiation emanated directly from the low emissivity wall itself. The combination of high and low emissivity wall surfaces allows the blackbody to reduce the influence of the environmental temperature while maintaining emissivity approaching unity.Type: GrantFiled: October 17, 2001Date of Patent: September 10, 2002Assignee: Advanced Monitors Corp.Inventor: Jacob Fraden
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Publication number: 20020122457Abstract: A thermometer calibration method and fixed-point temperature realizing apparatus uses a fixed-point cell including a crucible of carbon and a fixed-point material enclosed in the crucible. The fixed-point material is a eutectic structure of carbide and carbon. The fixed-point cell is placed in a furnace for increasing and decreasing the environmental temperature of the cell. A thermometer to be calibrated is used to measure temperature variations in the cell and calibrated based on the temperature variations thus measured.Type: ApplicationFiled: March 4, 2002Publication date: September 5, 2002Applicant: National Inst. of Advanced Ind. Science and Tech.Inventors: Naohiko Sasajima, Yoshiro Yamada
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Publication number: 20020106000Abstract: A virtual blackbody radiation system (10) includes a light-emitting unit (1) including an LED driven by a fixed current, a light-receiving unit (2) including a sapphire rod, and an optical unit (3) including lenses (31, 32) for converging light emitted by the light-emitting unit in a convergent light. A cylindrical member (41)included in the optical unit (3)can be moved along the optical axis by a servomotor (42) included in a focus adjusting unit (4) for positional adjustment. The focus of convergent light relative to the light-receiving unit (2) can be adjusted by moving the lens (32) disposed in the cylindrical member (41) along the optical axis relative to the light-receiving unit (2). The intensity of the convergent light on the light-receiving unit (2) can be adjusted to the intensity of predetermined blackbody radiation.Type: ApplicationFiled: March 16, 2000Publication date: August 8, 2002Inventors: Eisuke Morisaki, Masayuki Kitamura, Nobuaki Takahashi, Takashi Shigeoka
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Patent number: 6398405Abstract: The present invention is to realize fixed points in a temperature region exceeding the melting point of copper, thereby highly accurately calibrating all the thermometers used in a high temperature region such as a radiation thermometer, a thermocouple, and the like. A fixed-point crucible 1 comprises a crucible composed of carbon and a fixed-point material of high melting point enclosed in the wall of the crucible. The fixed-point material is carbon-metal eutectic structure. The crucible 1 is disposed in a temperature-variable furnace 6, the environmental temperature of the crucible 1 is increased and decreased by the temperature-variable furnace 6, the temperature of the cavity in the crucible 1 at the time is measured with a thermometer 9 and the thermometer 9 is calibrated from the state of the temperature variation measured.Type: GrantFiled: December 10, 1999Date of Patent: June 4, 2002Assignee: Agency of Industrial Science and TechnologyInventor: Yoshiro Yamada
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Patent number: 6390668Abstract: A source of thermal radiation for calibrating or testing infrared thermometers or detectors, in which improved temperature uniformity of the radiation-emitting surface is achieved by supplying heat to that surface by condensation of a working fluid as in a heat pipe. With appropriate selection of the working fluid, a wide range of temperatures is possible. Air convection currents at the radiation-emitting opening of the device may be suppressed by creation of a transition region of heated air by a baffle and air heater, further improving the temperature uniformity of the radiation-emitting surface.Type: GrantFiled: June 26, 2000Date of Patent: May 21, 2002Inventor: Peter Albert Materna
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Publication number: 20020021739Abstract: A blackbody cavity having two types of wall surfaces wherein a first type has high emissivity and a second type has low emissivity. The low emissivity wall surface has an aperture from where the infrared radiation escapes the cavity, and is preferably shaped to minimize the escape through the aperture of radiation emanated directly from the low emissivity wall itself. The combination of high and low emissivity wall surfaces allows the blackbody to reduce the influence of the environmental temperature while maintaining emissivity approaching unity.Type: ApplicationFiled: October 17, 2001Publication date: February 21, 2002Applicant: Advanced Monitors Corp.Inventor: Jacob Fraden
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Patent number: 6345909Abstract: A calibration instrument for calibrating a temperature probe, such as pyrometer, uses a stable light source and a filter to simulate a blackbody of a known temperature. An alignment tool aligns a light-emitting surface of the calibration instrument to the input of the temperature probe. The calibration instrument may include a fiber optic bundle to transmit light from the light source to the light emitting surface.Type: GrantFiled: December 7, 1999Date of Patent: February 12, 2002Assignee: Applied Materials, Inc.Inventor: Mark Yam
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Patent number: 6293696Abstract: 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.Type: GrantFiled: May 3, 1999Date of Patent: September 25, 2001Assignee: Steag RTP Systems, Inc.Inventor: Julio L. Guardado
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Publication number: 20010019572Abstract: A radiometer calibrating system utilizes an adjustable noise source for calibrating a radiometer. The noise source includes a transistor configured as a noise equivalent circuit having a gate port, drain port and source port. A source inductance providing series feedback for the noise source has one end coupled to the source port of the noise equivalent circuit and another end connected to the ground. A bias circuit controls the amount of DC bias applied to the noise equivalent circuit. In order to match the impedances in the noise source, an output impedance matching network is connected to the drain port and an input impedance matching network is connected to the gate port of the noise equivalent circuit. The output and input impedance networks have an output port and input port, respectively.Type: ApplicationFiled: February 8, 2001Publication date: September 6, 2001Inventors: Robert S. Roeder, Matthew C. Smith, Lawrence P. Dunleavy, Steven M. Lardizabal
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Patent number: 6283629Abstract: A method of calibrating a radiation thermometer including a radiation sensor that is characterized by a sensitivity (S) and a temperature-responsive resistor that serves as an ambient temperature sensor, the temperature-responsive resistor having at a specified reference temperature a reference resistance (R0).Type: GrantFiled: April 4, 2000Date of Patent: September 4, 2001Assignee: Braun GmbHInventors: Bernhard Kraus, Frank Beerwerth, Klaus Heubach, Manfred Kaiser
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Patent number: 6280081Abstract: A calibration current source and methods of calibrating temperature measurements made during, e.g., an RTP process are described. The calibration current source preferably includes a biasing circuit, an output transistor current source, and an offset circuit. The biasing circuit has an input, a reference voltage output and a biasing voltage output. The output transistor current source is coupled to the biasing voltage output and is configured to produce an output current. The offset circuit is coupled in a feedback loop between the reference voltage output and the biasing circuit input and is configured to generate from the reference voltage output a variable offset voltage for selectively controlling the biasing voltage applied to the output transistor current source. In a temperature calibrating method a calibration table is generated by applying a plurality of input signals to a calibration current source to produce a plurality of output signals. The calibration table is stored.Type: GrantFiled: July 9, 1999Date of Patent: August 28, 2001Assignee: Applied Materials, Inc.Inventors: David Blau, Elia Jadushlever
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Patent number: 6267501Abstract: A method for measuring the temperature of a scene using a detector having at least one reference pixel, with an integratable sampling circuit associated with each pixel. Initially, an ambient reference temperature is observed with the reference pixel(s) to provide a parameter, generally voltage, indicative of that temperature to provide a constant voltage output indicating that temperature by varying the sampling circuit integration time. Each non-reference pixel is exposed to different scene and ambient temperatures and the integration time for each set of data for each pixel is recorded. For each pixel, an equation is provided relating integration time to pixel voltage when the ambient temperature and the scene temperature are the same to correct for offsets and an equation is provided relating integration time and offset corrected pixel value to the difference between the ambient temperature and the scene temperature when the ambient temperature and scene temperature differ for correction of responsivity.Type: GrantFiled: April 1, 1999Date of Patent: July 31, 2001Assignee: Raytheon CompanyInventors: Martin A. Wand, Kenneth Rachels, John F. Brady, Michael Weinstein, David D. Ratcliff
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Patent number: 6193411Abstract: The present invention relates to a calibrator for contact and non-contact thermometers, comprising a metallic body which comprises two opposite end surfaces, wherein at least a first type of hole which is drilled into the metallic body for the insertion of a temperature control probe, and at least a second type of hole for the insertion of a temperature probe are mounted on one end surface; and the other end surface is coated with material to perform as radiative source; a heating device, for heating the metallic body, and temperature control device, for controlling the heating power of the heating device and for controlling the temperature of the metallic body. The present invention could be utilized to calibrate both contact and non-contact thermometers. The objective of integrating two functions into one device and thereby saving costs and space could be achieved.Type: GrantFiled: June 9, 1999Date of Patent: February 27, 2001Assignee: Industrial Technology Research InstituteInventor: Shen-Jen Chen
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Patent number: 6179466Abstract: A method of correcting a temperature probe reading in a thermal processing chamber for heating a substrate, including the steps of heating the substrate to a process temperature and using a first, a second and a third probe to measure the temperature of the substrate. The first probe has a first effective reflectivity and the second probe has a second effective reflectivity. The first probe produces a first temperature indication, the second probe produces a second temperature indication and the third probe produces a third temperature indication. The first and second effective reflectivities may be different. From the first and second temperature indications, a corrected temperature reading for the first probe may be derived, wherein the corrected temperature reading is a more accurate indicator of an actual temperature of the substrate than an uncorrected readings produced by both the first and second probes.Type: GrantFiled: March 18, 1998Date of Patent: January 30, 2001Assignee: Applied Materials, Inc.Inventors: Bruce W. Peuse, Gary E. Miner, Mark Yam, Aaron Hunter, Peter Knoot, Jason Mershon
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Patent number: 6179465Abstract: A calibration instrument for calibrating a temperature probe, such as pyrometer. The calibration instrument uses two stable light sources, such as light emitting diodes, to simulate a blackbody of a known temperature.Type: GrantFiled: May 22, 1997Date of Patent: January 30, 2001Assignee: Applied Materials, Inc.Inventor: Mark Yam
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Patent number: 6086245Abstract: A calibration instrument for calibrating a temperature probe, such as pyrometer, uses a stable light source, such as a light emitting diode, to simulate a blackbody of a known temperature. The light source is located inside a chamber and emits light through an aperture. The calibration instrument may be inserted into a thermal processing chamber, or the temperature probe may be removed from the chamber. An alignment tool aligns the aperture to the input of the temperature probe. The calibration instrument may be integrated with the alignment tool, or it may be removable.Type: GrantFiled: September 16, 1998Date of Patent: July 11, 2000Assignee: Applied Materials, Inc.Inventor: Mark Yam
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Patent number: 6065866Abstract: A method of calibrating a radiation thermometer including a radiation sensor and an ambient temperature sensor, the method including the steps of using a first radiation standard having a known temperature T.sub.S (1) and with the ambient temperature sensor at a first ambient temperature T.sub.U (1), using the radiation thermometer to read the temperature of the first radiation standard and while doing so, measuring a first output signal U(1) of the radiation sensor; using a second radiation standard having a known temperature T.sub.S (2) and with the ambient temperature sensor again at the first ambient temperature T.sub.U (1), using the radiation thermometer to read the temperature of the second radiation standard and while doing so, measuring a second output signal U(2) of the radiation sensor; and calibrating the radiation sensor and the ambient temperature sensor by using the values obtained for U(1) and U(2) and without using a value for T.sub.Type: GrantFiled: November 21, 1997Date of Patent: May 23, 2000Assignee: Braun AktiengesellschaftInventors: Bernhard Kraus, Frank Beerwerth, Klaus Heubach, Manfred Kaiser
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Patent number: 6056433Abstract: A calibration instrument for calibrating a temperature probe, such as pyrometer, uses a stable light source and a filter to simulate a blackbody of a known temperature. An alignment tool aligns a light-emitting surface of the calibration instrument to the input of the temperature probe. The calibration instrument may include a fiber optic bundle to transmit light from the light source to the light emitting surface.Type: GrantFiled: January 15, 1998Date of Patent: May 2, 2000Assignee: Applied Materials, Inc.Inventor: Mark Yam
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Patent number: 5988874Abstract: A method for calibrating an optical pyrometer to an external reference point. By changing the focus of the optical pyrometer without physically moving the pyrometer, calibration of the optical pyrometer can be accomplished without modifying the semiconductor operation. Broadly speaking, the present invention contemplates an apparatus for calibrating an optical pyrometer. The apparatus includes a first optical source in a heating chamber with an optical port, an optical pyrometer, a mirror, and a second optical source. The optical pyrometer is positioned to receive light rays from a first optical source residing inside the heating chamber. The second optical source is located external to the heating chamber. The second optical source serves as an external reference point. The external location of the second optical source allows for calibration of the optical pyrometer without modification of the heating chamber or the first optical source residing inside the heating chamber.Type: GrantFiled: September 5, 1997Date of Patent: November 23, 1999Assignee: Advanced Micro Devices, Inc.Inventor: Don R. Rohner
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Patent number: 5848842Abstract: A method of calibrating a temperature measurement system including the steps of heating a first substrate having a high emissivity value to a first process temperature; while the first substrate is at the first process temperature, calibrating a first probe and a second probe to produce temperature indications from the first substrate that are substantially the same, the first probe having associated therewith a first effective reflectivity and the second probe having associated therewith a second effective reflectivity, the first and second effective reflectivities being different; heating a second substrate having a low emissivity value to a second process temperature, the low emissivity value being lower than the high emissivity value; with the second substrate at the second process temperature, using both the first probe and the second probe to measure the temperature of the second substrate, the first probe producing a first temperature indication and the second probe producing a second temperature indicType: GrantFiled: May 20, 1996Date of Patent: December 15, 1998Assignee: Applied Materials, Inc.Inventors: Bruce W. Peuse, Gary E. Miner, Mark Yam
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Patent number: 5820261Abstract: A calibration instrument for calibrating a temperature probe, such as pyrometer, uses a stable light source, such as a light emitting diode, to simulate a blackbody of a known temperature. The light source is located inside a chamber and emits light through an aperture. The calibration instrument may be inserted into a thermal processing chamber, or the temperature probe may be removed from the chamber. An alignment tool aligns the aperture to the input of the temperature probe. The calibration instrument may be integrated with the alignment tool, or it may be removable.Type: GrantFiled: July 26, 1995Date of Patent: October 13, 1998Assignee: Applied Materials, Inc.Inventor: Mark Yam
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Patent number: 5762419Abstract: A calibration instrument for calibrating a temperature probe, such as pyrometer, uses a stable light source and a filter to simulate a blackbody of a known temperature. An alignment tool aligns a light-emitting surface of the calibration instrument to the input of the temperature probe. The calibration instrument may include a fiber optic bundle to transmit light from the light source to the light emitting surface.Type: GrantFiled: March 28, 1996Date of Patent: June 9, 1998Assignee: Applied Materials, Inc.Inventor: Mark Yam
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Patent number: 5755511Abstract: A method of correcting a temperature probe reading in a thermal processing chamber for heating a substrate, including the steps of heating the substrate to a process temperature; using a first, a second and a third probe to measure the temperature of the substrate, the first and third probes having a first effective reflectivity and the second probe having a second effective reflectivity, the first probe producing a first temperature indication, the second probe producing a second temperature indication and the third probe producing a third temperature indication, and wherein the first and second effective reflectivities are different; and from the first and second temperature indications, deriving a corrected temperature reading for the first probe, wherein the corrected temperature reading is a more accurate indicator of an actual temperature of the substrate than an uncorrected readings produced by both the first and second probes.Type: GrantFiled: May 1, 1996Date of Patent: May 26, 1998Assignee: Applied Materials, Inc.Inventors: Bruce W. Peuse, Gary E. Miner, Mark Yam
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Patent number: 5746511Abstract: A temperature transmitter and a process control system includes a sensor input for coupling to a temperature sensor having a temperature dependent resistance. The resistance measuring circuitry couples to the sensor input and provides a resistance output related to resistance of the temperature dependent resistance. Analog to digital conversion circuitry couples to the sensor input and provides a digital output related to AC signals across the sensor input. Digital signal processing circuitry isolates a Johnson noise component of the AC signals and provides a digitized Johnson noise output. Temperature measurement circuitry provides a calibrated temperature output based upon the resistance output and the digitized Johnson noise output. Output circuitry transmits the calibrated temperature output over the process control loop.Type: GrantFiled: January 3, 1996Date of Patent: May 5, 1998Assignee: Rosemount Inc.Inventors: Evren Eryurek, Gary Lenz
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Patent number: 5703276Abstract: A cell for testing passive remote vapor detectors has a cell body with a blackbody radiation source attached to a first end and a window attached to a second end. The blackbody radiation source and the window seal the first and second ends, so that a hazardous vapor can be easily contained. With this arrangement, it is easy to account for the effects of the window on output radiation and thus to calculate radiance and temperature quantities of interest.Type: GrantFiled: May 30, 1996Date of Patent: December 30, 1997Assignee: The United States of America as represented by the Secretary of the ArmyInventor: Dennis F. Flanigan
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Patent number: 5608838Abstract: A blackbody type heating element for calibration furnaces employs an elongated hollow cylinder of graphite open at first and second opposite ends. The cylinder has an integral solid graphite partition centrally disposed in the cylinder and oriented at right angles to an axis of elongation of the cylinder. First and second end caps are disposed adjacent corresponding ones of the first and second cylinder ends. Each cap has a first electrically conductive member adapted to be connected as an electrode to a suitable source of electrical energy and a second graphite type hollow cylindrical member open at both ends engaging the first member. The second member has a coating of pyrolytic graphite. Each second member is connected directly through its coating to the corresponding end of the cylinder. The openings in the second member are aligned with this corresponding end.Type: GrantFiled: December 7, 1994Date of Patent: March 4, 1997Inventor: Charles E. Brookley
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Patent number: 5553939Abstract: A method of calibrating an optical pyrometer comprising placing an oven, a wafer with a reference region on at least part of one of its faces, the reference region having an electromagnetic wave reflection discontinuity at a known temperature value, transmitting an electromagnetic wave in the direction of the reference region, measuring and recording the intensity of the wave reflected by the reference region, measuring and recording the temperature of the reference region by means of the optical pyrometer to be calibrated, increasing the temperature of the oven, determining the moment when a discontinuity in the reflection of the electromagnetic wave is observed, registering the temperature value measured by the pyrometer at this moment, comparing this measured temperature value with the known temperature value, and causing the temperature value measured by the pyrometer and the known temperature value to coincide.Type: GrantFiled: October 28, 1993Date of Patent: September 10, 1996Assignee: Commonaute Economique Europeenne (CEE)Inventors: Jean-Marie Dilhac, Christian Ganibal, Bernard Rousset
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Patent number: 5331311Abstract: A temperature sensor assembly for monitoring railroad car wheels includes an array of temperature detectors arranged to generate a temperature profile of the wheel. The array may be formed integrally with imaging elements and signal conditioning elements on a single IC chip. The assembly may be arranged to monitor the wheel either transversely or in parallel to the direction of wheel movement.Type: GrantFiled: December 9, 1992Date of Patent: July 19, 1994Assignee: Servo Corporation of AmericaInventor: Alan P. Doctor
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Patent number: 5326170Abstract: A method for calibrating at least one temperature sensor. A wafer (30) having calibration structures of a material having a melting point in the range of 150.degree. to 1150.degree. C. is provided. The temperature sensor is operable to detect a temperature dependent characteristic of the wafer and output a signal corresponding to the temperature depending characteristic. The power input is selectively varied and the wafer temperature is ramped for a calibration run. A wafer characteristic, such as wafer reflectance, radiance, or emissivity, is monitored. A first step change in the wafer characteristic corresponding to a wafer temperature equal to the melting point of the calibration structures is detected and a set of calibration parameters for each temperature sensor being calibrated is calculated.Type: GrantFiled: September 1, 1993Date of Patent: July 5, 1994Assignee: Texas Instruments, IncorporatedInventors: Mehrdad M. Moslehi, Habib Najm, Lino A. Velo
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Patent number: 5324937Abstract: An improved target for testing and calibrating a detection device. The target (10) includes a metal substrate (12) with a first layer (14) of high emissivity material and a second layer (16) of low emissivity material are deposited thereon. In the specific implementation, the substrate (12) is copper, the first layer (14) is chromium-oxide and the second layer (16) is chrome. In the illustrative embodiment, an aperture (22) is drilled through the substrate (12) and the first and second layers (14, 16) thereon. An infrared emitter (20) is located at the aperture (22) to provide point source radiation. A conventional heater (26) is applied to the back surface of the target. A pattern is etched on second layer (16) on the front surface of the target using electron beam lithography. The use of a metal substrate (12) allows for the drilling of small holes more easily than in the conventional target.Type: GrantFiled: January 21, 1993Date of Patent: June 28, 1994Assignee: Hughes Aircraft CompanyInventors: Wallace W. Chen, I-Fu Shih
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Patent number: 5292090Abstract: A simulator is provided for verifying the proper operation of railroad rolling stock hot wheel detectors. The simulator includes heaters mounted on trucks of a railroad car, between the wheels and within the profile of the thickness of the wheels. Shock mounts, spring mounts and safety cables are used. An electromagnet is mounted on the heater to trip a sensor to activate the detector and a sensor on the car is used to determine the ambient temperature. Each heater includes a heater temperature sensor and is maintained at a constant temperature above ambient to approximate the thermal radiation of a hot wheel. Each heater is adjusted to direct heat horizontally outwardly from the truck to permit a hot wheel detector adjacent to and outside of the rail to detect a hot wheel. The car has two trucks with one heater on each side of each truck. One heater on each side simulates a temperature approximately equal to a hot wheel.Type: GrantFiled: December 2, 1992Date of Patent: March 8, 1994Assignee: Meg Trans Corp.Inventors: Donald C. Wetzel, Walter N. Arth, Jr.
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Patent number: 5265958Abstract: A thermal imager testing device (10) incorporates a pattern plate (32) with patterns (P0, P1, P2 and P3) cut through it. Patterns (P0 and P1) are of like spatial frequency, whereas patterns (P2 and P3) have respective relatively higher spatial frequencies. The patterns (P0 to P3) are like structured and like oriented, and they underlie blackbodies (34, 26, 28 and 30) respectively. Temperature differentials between the blackbodies (34 and 26 to 30) are maintained at constant values by temperature control circuits. The temperature of blackbody (34) is adjustable. The pattern plate (32) and underlying blackbodies are viewed by a thermal imager under test. The temperature of the blackbody (34) is adjusted until pattern (P0) is just discernable as cold relative to the pattern plate (32). If the thermal imager performance is acceptable patterns (P1 to P3) are then just discernable as hot relative to the pattern plate (32).Type: GrantFiled: February 14, 1992Date of Patent: November 30, 1993Assignee: The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom and Northern IrelandInventor: John H. Ludlow
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Patent number: 5183337Abstract: A black body for calibrating an infrared thermometer includes a cavity and is configured to float stably on a surface of a volume of liquid with the cavity in close thermal contact with the liquid and the opening exposed above the surface.Type: GrantFiled: July 8, 1991Date of Patent: February 2, 1993Assignee: Exergen CorporationInventor: Francesco Pompei
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Patent number: 5178464Abstract: A sensor includes two thermal energy detectors thermally insulated from one another. The first detector is warmed or cooled by radiation between it and the object being measured. The second detector is warmed or cooled by exchange of thermal energy with a thermal reference source until the second detector reaches a temperature that is a predetermined ratio with that of the first detector. A control circuit which receives signals from the detectors that represent their temperatures, provides control for the thermal reference. A third detector measures the temperature of the thermal reference source and provides a signal representative of the temperature of the reference source. A processor receives the signal from the third detector and provides a signal indicative of the temperature of the object.Type: GrantFiled: April 19, 1991Date of Patent: January 12, 1993Assignee: Thermoscan Inc.Inventor: Jacob Fraden
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Patent number: 5128884Abstract: Techniques for calibrating differential temperature sources including the use of a calibrated infrared imaging sensor having an associated calibrated temperature function that is expressed as a function of a predetermined calculated parameter indicative of the actual differential temperature of a differential temperature source. The temperature source being calibrated is thermally imaged at different indicated differential temperatures to provide thermal images associated with the indicated temperatures, and such images are processed to define the calculated parameter as as function of indicated temperature. The calculated parameter function is substituted in the calibrated temperature function to provide a calibrated temperature function that is expressed as a function of indicated differential temperature.Type: GrantFiled: May 31, 1991Date of Patent: July 7, 1992Inventor: Kenneth E. Prager
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Patent number: 5100243Abstract: This invention relates to a device for monitoring the temperature of the wheels of passing railroad cars. More particularly, this device includes a self-calibration function wherein a predetermined heat source is attached to the device, a fixed amplifier amplifies the resulting electric signal so as to generate a signal comparable in magnitude to that generated by a passing train, a variable gain amplifier further amplifies the signal, and the resulting signal is converted to a digital signal. The digital signal is used as a signal to the feedback input of a variable gain amplifier. In response to the digital signal, the variable gain amplifier adjusts its gain until the feedback signal reaches a predetermined value.Type: GrantFiled: December 12, 1990Date of Patent: March 31, 1992Assignee: Servo Corporation of AmericaInventors: George Grosskopf, W. Woodward Sanville
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Patent number: 5089749Abstract: A method and apparatus for measuring and adjusting output of a heat lamp for an optical TLD reader includes an optical system which matches the optical system of the TLD reader, means for supporting a heat lamp to be calibrated, and an element plate having at least one heat absorbing substrate supported in alignment with the optical system. The heat lamp is electrically connected to a lamp driver circuit of the TLD reader, and a thermocouple is mounted in thermal contact with the heat absorbing substrate. In use, the lamp driver circuit of the TLD reader drives the heat lamp mounted in the calibration and adjusting device. This device monitors the signal generated by the thermocouple and displays this signal as a measured heat response curve. This measured heat response curve can be compared with a `standard` or reference heat response curve to determine whether the lamp driver circuit has been adjusted properly for the heat lamp being tested, and to determine the nature of any required adjustments.Type: GrantFiled: January 28, 1991Date of Patent: February 18, 1992Assignee: Commonwealth Edison CompanyInventor: Richard Cadogan
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Patent number: 5001657Abstract: A radiation thermometer has a detector for receiving radiation energy from a target object, and the detector generates an AC signal as a result of movement of a chopper. The AC signal is rectified by a rectifying circuit and the rectified signal is supplied to a microcomputer. On the other hand, temperatures around the detector are detected by a temperature sensor and the temperature of the target object is measured based on those detected values. In addition, the radiation thermometer has various calibration modes other than a measurement mode. In a calibration mode I, calibration data concerning a difference in characteristics of the temperature sensor for each thermometer is obtained. Data for correcting timing for synchronous rectification by the rectifying circuit is obtained in a calibration mode II. Calibration data for calculation of the temperature of the target object is obtained in a calibration mode III.Type: GrantFiled: December 6, 1989Date of Patent: March 19, 1991Assignee: Minolta Camera Kabushiki KaishaInventors: Hirokazu Yagura, Kenji Imura
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Patent number: 4969748Abstract: The present invention is a method and apparatus for calibrating a temperature feedback value in a wafer processing chamber to automatically compensate for variations in infrared emissions from a heated semiconductor wafer due to variations in composition and coatings from wafer to wafer. A calibration wafer with an imbedded thermocouple is used to generate a table relating actual wafer temperatures to power supplied to the heating chamber and infrared emissions detected by a pyrometer. A sample wafer of a batch to be processed is subsequently placed in the chamber at a known power level, and any difference between the detected infrared emission value and the value in the table is used to adjust the entire table according to a first predetermined formula or table. Before each wafer is processed, a known source of infrared light is reflected off the wafer and detected. The reflected light value is compared to a reflection measurement for the sample wafer.Type: GrantFiled: April 13, 1989Date of Patent: November 13, 1990Assignee: Peak Systems, Inc.Inventors: John L. Crowley, Ahmad Kermani, Stephan E. Lassig, Noel H. Johnson, Gary R. Rickords
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Patent number: 4900162Abstract: A biomedical thermometer for taking the temperature of a person at various body sites, including the ear, includes a radiation detector, a temperature detector for measuring the temperature of the radiation detector, and a heating and cooling unit for changing the temperature of the radiation detector. The system also includes a temperature processor for generating an output proportional to the absolute temperature of the radiation detector, responsive to signals generated by the radiation detector and the temperature detector.Type: GrantFiled: March 20, 1989Date of Patent: February 13, 1990Assignee: IVAC CorporationInventors: Kenneth A. Beckman, John A. Graham
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Patent number: 4880314Abstract: 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.Type: GrantFiled: June 17, 1986Date of Patent: November 14, 1989Assignee: VEB Messgeraetewerk "Erich Weinert" Magdeburg, Betrieb des Kombinates VEB EAW Berlin-TreptowInventor: Ulrich Kienitz
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Patent number: 4859075Abstract: A laser thermal testing method and system for use in testing a fire alarm system which has a plurality of heat-sensors which are remotely distributed throughout a protected area. The laser thermal testing system includes a first laser and a second laser. The first laser generates an aiming beam of coherent electromagnetic radiation in the visible spectrum. The laser thermal testing system also includes a movable reflector which reflects the aiming beam. The movable reflector is optically coupled to the first laser. The movable reflector is first moved in order to align the aiming beam in an aligned position so that the aiming beam is reflected onto one of the heat-sensors. The movable reflector is then fixedly secured in the aligned position. The second laser generates a heating beam of coherent electromagnetic radiation in the infrared spectrum.Type: GrantFiled: March 14, 1988Date of Patent: August 22, 1989Assignees: Directed Energy, Inc., Atlantic Richfield CompanyInventors: Leroy V. Sutter, Jr., Robert E. Mofley
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Patent number: 4821219Abstract: 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.Type: GrantFiled: June 17, 1986Date of Patent: April 11, 1989Assignee: VEB Messgeraetewerk "Erich Weinert" Magdeburg, Betrieb des KombinatesInventors: Ulrich Kienitz, Christian Schiewe
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Patent number: 4790324Abstract: A hand held probe unit has an infrared sensitive thermopile mounted in a metal housing kept at a constant reference temperature by a regulator circuit. A waveguide tube, surrounded by a thermally insulative probe, directs infrared emissions to the thermopile. The thermopile and regulator circuit of the probe unit are electrically connected to processing circuitry in a chopper unit. Prior to taking a patient's temperature, the probe unit is mated with the chopper unit so that the thermopile detects infrared emissions from a reference target which is also kept at a constant reference temperature by another regulator circuit. The processing circuitry repeatedly acquires the output level of the thermopile and stores calibration data. The probe unit is then removed from the chopper unit, the probe is covered with an IR transparent, disposable speculum, and is inserted in the patient's external ear canal.Type: GrantFiled: March 25, 1987Date of Patent: December 13, 1988Assignee: Intelligent Medical Systems, Inc.Inventors: Gary J. O'Hara, David B. Phillips
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Patent number: 4765749Abstract: Calorimeter for measuring the energy transported by radiation. This calorimeter comprises an absorbing element able to absorb radiation and having an outer face exposed to the radiation and an inner face, said element undergoing a temperature rise during the interaction with the radiation. This temperature rise is measured by a thermopile. The calorimeter also comprises calibration means constituted by a strip-like resistive deposit in direct contact with the inner face of the absorbing element over at least 50% of the surface thereof. Application to the measurement of the energy transported by electromagnetic radiation or a particle flux.Type: GrantFiled: December 15, 1986Date of Patent: August 23, 1988Assignee: Commissariat a l'Energie AtomiqueInventors: Jean-Luc Bourgade, Michel Le Guen, Alain Saleres
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Patent number: 4621265Abstract: An array of target elements having emissivity and reflectivity properties variable in accordance with a data processing simulation of the electromagnetic signature of a target and target terrain suitable for evaluating the tracking capabilities of an active/passive millimeter wave target seeker.Type: GrantFiled: September 30, 1982Date of Patent: November 4, 1986Assignee: The Boeing CompanyInventors: Leland C. Buse, George A. Eastman
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Patent number: 4549814Abstract: A thermal test pattern comprises motifs of a material having a high thermal emissivity which are provided on one side of a flat substrate. The substrate has a low thermal emissivity. The other side of the substrate is covered with a layer of a material having a high electrical resistivity which is provided between two conductive connection strips. The motifs and connection strips and resistive layer may be deposited by silk screening. Due to the differences in thermal emissivity, a temperature difference occurs between the substrate and the motifs, the motifs being colder, when the substrate is heated by passing an electric current through the resistive layer.Type: GrantFiled: December 1, 1983Date of Patent: October 29, 1985Assignee: U.S. Philips CorporationInventors: Georges N. Creel, Claude Morelle