Abstract: A temperature monitoring technique for collecting radiation intensity (blackbody emission) across a broad wavelength range. A solid state spectrometer (26) acquires spectra from a sample (10) in real time and resolves the spectra to a radiation intensity (I) versus wavelength (?) curve. This curve is fitted to Planck's equation using a non-linear least squares fitting analysis. The system can be configured to self-calibrate and then lock in an amplitude value (A) which is used in subsequent temperature measurements by fitting to the blackbody emission curve. Preferably, the spectrometer (26) is flat field corrected (36) in an initial step to counteract variations in the spectrometer response with wavelength.

Abstract: A method and system for calibrating temperature measurement devices, such as pyrometers, in thermal processing chambers are disclosed. According to the present invention, the system includes a calibrating light source that emits light energy onto a substrate contained in the thermal processing chamber. A light detector then detects the amount of light that is being transmitted through the substrate. The amount of detected light energy is then used to calibrate a temperature measurement device that is used in the system.

Abstract: Infrared IR thermometer calibration systems and methods are disclosed in which the temperature of an IR thermometer calibration system is controlled such that radiation emitted by a target at a given input temperature is equal to the radiation emitted by a graybody heated to the input temperature and having an emissivity equal to an emissivity setting of an IR thermometer to be calibrated using the IR thermometer calibration system.

Abstract: A method and apparatus for automated field calibration of temperature sensors uses a series of readings including a reading of a known source, such as an LED, for use in calculating a factor that is compared to a reference for adjusting the sensor output signal. Calibration readings are taken more frequently after start up to compensate for sensor drift during storage, as opposed to less frequent readings during operation to compensate for slower sensor drift while operational.

Abstract: Infrared Ir Thermometer Calibration Systems and Methods are Disclosed in which the temperature of an IR thermometer calibration system is controlled such that radiation emitted by a target at a given input temperature is equal to the radiation emitted by a graybody heated to the input temperature and having an emissivity equal to an emissivity setting of an IR thermometer to be calibrated using the IR thermometer calibration system.

Abstract: A method for on-orbit calibration of the temperature sensors of a simulated blackbody is disclosed. The method may include selecting a simulated blackbody traveling in a micro-gravity environment and comprising a sensor, a container positioned proximate the senor and containing a material, and a heat transfer device positioned proximate the at least one container. The heat transfer device may transition the material through a phase change. The temperature sensor may monitor the temperature of the material during the phase change. A correction may be calculated to correct any disparity between the temperature reported by the temperature sensor during the phase change and the known plateau temperature corresponding to that phase change. The correction may be applied to subsequent temperature readings obtained using the temperature sensor.

Abstract: The LED-radiance source is a suitable replacement of lamp-based integrating sphere sources where they are used as stable and uniform radiance sources. The LED-based radiance source includes an array of LEDs having substantially similar radiance output wavelengths and a radiation detector such as a photodiode that detects and monitors radiation directed from the LEDs. Temperature of the LEDs can be controlled by feedback from a photodiode, thereby allowing for control and stabilization of temperature-dependent radiation output.

Abstract: Methods and apparatus for wafer temperature measurement and calibration of temperature measurement devices may be based on determining the absorption of a layer in a semiconductor wafer. The absorption may be determined by directing light towards the wafer and measuring light reflected from the wafer from below the surface upon which the incident light impinges. Calibration wafers and measurement systems may be arranged and configured so that light reflected at predetermined angles to the wafer surface is measured and other light is not. Measurements may also be based on evaluating the degree of contrast in an image of a pattern in or on the wafer. Other measurements may utilize a determination of an optical path length within the wafer alongside a temperature determination based on reflected or transmitted light.

Abstract: A method of precisely measuring temperature of an object without having to setting the emissivity of the object over a wide temperature range from low to high temperature with a single radiation thermometer. The temperature-measuring device of the present invention includes a reference object having an emissivity of substantially 1 in a prescribed wavelength range; a bandpass filter transmitting radiant energy in the prescribed wavelength range; and a radiation thermometer for observing temperature by taking in the radiant energy transmitted through the bandpass filter.

Abstract: A temperature fixed-point cell is configured with a crucible composed of carbon and a fixed-point material enclosed in the crucible. The fixed-point material has a peritectic structure of carbon and a carbon compound. A thermometer is calibrated by installing the temperature fixed-point crucible in a furnace, increasing or decreasing the ambient temperature thereof, measuring the temperature of the temperature fixed-point cell with the thermometer, observing the state of temperature change, and using this state of temperature change as a basis for the calibration. This invention is aimed at realizing a fixed point in the temperature range exceeding the copper point and accomplishing great improvement in accuracy in the calibration of radiation thermometers, thermocouples and all thermometers used in high temperature ranges.

Abstract: An infrared sensor calibration system including a calibration body at a known temperature a fixture for a package with at least two infrared sensors each aimed at a different location on the calibration body. Relative motion is provided between the calibration body and the fixture so each infrared sensor is immune to temperature variations across the calibration body during calibration of the infrared sensors.

Abstract: A sensor device formed on a semiconductor substrate. The device comprises a thermal radiation sensor including a sensing cell and a referencing cell which are co-operable for providing a first output signal indicative of the temperature fluctuation resulting from incident radiation. A gradient sensor including a pair of cells spatially located on the semiconductor substrate is provided which are co-operable to provide a second output signal indicative of the temperature gradient across the semiconductor substrate for facilitating calibrating the first output signal. At least one of the cells of the gradient sensor is not common to the cells of the thermal radiation sensor.

Abstract: The present invention provides a non-destructive method for monitoring and calibrating chamber temperature. One embodiment of the present invention provides a method for measuring temperature comprising forming a target film on a test substrate at a first temperature, wherein the target film has one or more properties responsive to thermal exposure, exposing the target film to an environment at a second temperature in a range higher than the first temperature, measuring the one or more properties of the target film after exposing the target film to the environment at the second temperature, and determining the second temperature according to the measured one or more properties.

Abstract: There is provided an in-furnace temperature measuring method that is capable of reducing the number of operation steps that are required for temperature measurement, and effectively applying a measurement result even if colors and finishing states of a circuit board and an electronic part are changed. First and second pseudo circuit boards (12) and (13) having the substantially same configuration and dimensions as those of a circuit board are inserted into a reflow furnace (11), the front and rear surface temperatures of the first and second pseudo circuit boards (12) and (13) and air temperatures around the first and second pseudo circuit boards (12) and (13) within the reflow furnace (11) are measured. The entire surface of a metal whose physical value is known is black-coated in the first pseudo circuit board (12), and the entire surface of a metal whose given physical value is known is mirror-finished in the second pseudo circuit board (13).

Abstract: Methods and apparatus for wafer temperature measurement and calibration of temperature measurement devices may be based on determining the absorption of a layer in a semiconductor wafer. The absorption may be determined by directing light towards the wafer and measuring light reflected from the wafer from below the surface upon which the incident light impinges. Calibration wafers and measurement systems may be arranged and configured so that light reflected at predetermined angles to the wafer surface is measured and other light is not. Measurements may also be based on evaluating the degree of contrast in an image of a pattern in or on the wafer. Other measurements may utilize a determination of an optical path length within the wafer alongside a temperature determination based on reflected or transmitted light.

Abstract: The present invention provides a radiation apparatus with capability of preventing heat convection, which comprises a blackbody furnace having a cavity therein and an air pressure adjusting unit. The air pressure adjusting unit coupled to the blackbody furnace for adjusting the air pressure of the open end of the cavity according to the temperature difference between the cavity and the outside environment. By means of the design of the present invention, it is capable of preventing heat convection between the cavity and the outside environment by utilizing the air pressure adjusting unit for controlling the air pressure status around the open end of cavity such that the blackbody furnace is stable for services of calibrations and tests.

Abstract: Infrared IR thermometer calibration systems and methods are disclosed in which the temperature of an IR thermometer calibration system is controlled such that radiation emitted by a target at a given input temperature is equal to the radiation emitted by a graybody heated to the input temperature and having an emissivity equal to an emissivity setting of an IR thermometer to be calibrated using the IR thermometer calibration system.

Abstract: A system and method is disclosed that reliably determines the transmissivity of a substrate. By determining the transmissivity of a calibration substrate, for instance, a temperature measuring device can be calibrated. The method and system are particularly well suited for use in thermal processing chambers that process semiconductor wafers used for forming integrated circuit chips.

Abstract: A probe cover having a portion that operates as a blackbody. The blackbody is a combination of a stretchable film and a metal. The blackbody rapidly heats to equilibrium with the body tissue. An infrared thermometer using the probe cover may view the blackbody to acquire the temperature of the body tissue temperature being measured.

Abstract: A method for calibrating a thermometer is disclosed. The thermometer comprises a primary temperature sensor for determining the temperature of a target. The thermometer also comprises a reference temperature sensor positioned proximate to the primary temperature sensor and being responsive to an extraneous temperature affecting the primary temperature sensor. One calibration method calibrates the reference temperature sensor. This calibration can utilize a non-electrically conductive liquid bath for temperature control. Another calibration method calibrates the reference temperature sensor and the primary temperature sensor.

Abstract: The present invention discloses a method for calibrating an infrared thermometer, which can obtain a sensitivity of a radiation sensor of an infrared thermometer and a reference resistance of an ambient-temperature sensor of the infrared thermometer. The method of the present invention uses an infrared thermometer to detect two test objects respectively placed in two environments having different ambient temperatures to obtain output signals of the radiation sensor and resistances of the ambient-temperature sensor from the two test objects. Then, the method of the present invention uses the output signals of the radiation sensor and the resistances of the ambient-temperature sensor to work out the sensitivity of the radiation sensor and the reference resistance of the ambient-temperature sensor.

Abstract: A fixed-point cell is provided which can provide a fixed-point in a wide temperature range by changing the fixed-point material. During the use of the fixed-point cell, the fixed-point material can be prevented from being contaminated, and the crucible of the cell can be prevented from being cracked. The fixed-point cell includes: the crucible composed of carbon; the fixed-point material enclosed in the crucible and composed of one of a metal, a eutectic of a metal and carbon, and a eutectic of a metal carbide and carbon; and a woven fabric of graphite fibers containing 10 ppm or lower of impurities and interposed between the crucible and the fixed-point material.

Abstract: A system and method for testing and calibrating integrated sensor devices that improves the manufacturing test throughput of the devices. The system includes a tester, a temperature controller, and at least one probe station including a thermal chuck. The chuck can be heated to specified temperatures to achieve variable heating of a wafer, PCB, or pallet disposed thereon. The temperature controller adjusts the temperature of the chuck to a first specified level. The tester performs at least one first measurement of the output offset of each integrated sensor embodied as a die on the wafer, or as a device on the PCB or pallet. Next, the temperature controller adjusts the temperature of the chuck to a second specified level, and the tester performs at least one second measurement of the output offset of each integrated sensor at the second temperature level.

Abstract: A wind velocity measuring apparatus. The apparatus includes a thermal sensor and a processor operatively coupled to the thermal sensor. The processor is configured to receive a first temperature reading from the thermal sensor of a beginning temperature sensed by the thermal sensor and to receive a second temperature reading from the thermal sensor of an ending temperature sensed by the thermal sensor after a quantifiable amount of heat is applied to the thermal sensor for a quantifiable amount of time. The processor is further configured to determine a theoretical temperature based on the quantifiable amount of heat, the quantifiable amount of time, and the beginning temperature and to determine a wind velocity based on the difference between the theoretical temperature and the ending temperature.

Abstract: A thermal imaging system and method for quantitative thermal mapping of a scene. The system comprises a thermal imaging device, a heat source of known temperature and emissivity located within the scene viewed by the thermal imaging device and a processor adapted to generate a calibrated temperature map of the scene from the data supplied by the thermal imaging device, based on the known temperature of the heat source. This enables accurate temperature measurements to be made using inexpensive uncooled Focal Plane Array detectors.

Abstract: The present standard radiation source comprises a black body having a cavity, a shielding plate positioned at an open end of the cavity, at least one first heater positioned in the shielding plate, at least one second heater positioned on the outer wall of the black body, a first insulation device covering the second heater and a temperature-controlling device positioned on the first insulation device.

Abstract: The present invention discloses a method for calibrating an infrared thermometer, which can obtain a sensitivity of a radiation sensor of an infrared thermometer and a reference resistance of an ambient-temperature sensor of the infrared thermometer. The method of the present invention uses an infrared thermometer to detect two test objects respectively placed in two environments having different ambient temperatures to obtain output signals of the radiation sensor and resistances of the ambient-temperature sensor from the two test objects. Then, the method of the present invention uses the output signals of the radiation sensor and the resistances of the ambient-temperature sensor to work out the sensitivity of the radiation sensor and the reference resistance of the ambient-temperature sensor.

Abstract: A calibration method for infrared temperature measuring instruments is disclosed. The calibration method of the present invention comprises the following five steps: (1) Calibrating the heat-flux resistor of an infrared temperature measuring instrument so as to obtain its calibrated resistance value (2) Using a digital multimeter to measure the parameters of the components and relevant circuits of the infrared temperature measuring instrument (3) Placing the infrared temperature measuring instrument in a blackbody radiation furnace so as to measure a single-point parameter of the blackbody radiation amplifier because the blackbody radiation furnace can provide a standard blackbody radiation source (4) Using the linear equation to obtain two additional parameters at two other temperatures so as to obtain a linear curve of the blackbody radiation amplifier (5) Storing the calibrated parameters in the memory of the infrared temperature measuring instrument.

Abstract: A method of linearizing the output a infrared camera having an InGaAs includes determining the an equivalent black body temperature of an object by utilizing a plurality of calibration constants determined by collecting data from a number of temperatures of the object, and determining a target temperature of the object by utilizing the equivalent black body temperature and the emissivity of the object.

Abstract: Methods and apparatus for wafer temperature measurement and calibration of temperature measurement devices may be based on determining the absorption of a layer in a semiconductor wafer. The absorption may be determined by directing light towards the wafer and measuring light reflected from the wafer from below the surface upon which the incident light impinges. Calibration wafers and measurement systems may be arranged and configured so that light reflected at predetermined angles to the wafer surface is measured and other light is not. Measurements may also be based on evaluating the degree of contrast in an image of a pattern in or on the wafer. Other measurements may utilize a determination of an optical path length within the wafer alongside a temperature determination based on reflected or transmitted light.

Abstract: A method and system for measuring remotely the surface temperature of a silicon wafer and layers, without the need to know the surface emissivity. The surface temperature is measured in-situ and in real-time during a high-temperature process, in a vacuum system, by using the linear polarization property of radiation. A blackbody source is heated to various, known temperatures, and provides radiation that impinges on the silicon surface and is reflected from it together with a self-emitted component. This combined reflected radiation is polarized and filtered to an appropriate wavelength, and observed with an imaging camera. Pairs of orthogonally polarized images of the surface are obtained for a set silicon surface temperature and for each blackbody temperature. The pairs of images are analyzed, pixel by pixel, to obtain a null polar level indicative of the surface temperature.

Abstract: A portable test apparatus for testing the accuracy of a radiation-sensing thermometer. The portable test apparatus comprises a target adapted to be maintained at a target temperature for sensing by the radiation-sensing thermometer. The apparatus also comprises a communication link adapted to receive temperature-sensing information from the radiation-sensing thermometer. The apparatus also comprises a processor adapted to analyze the received temperature-sensing information and to provide an indication to a user about whether the thermometer is functioning properly.

Abstract: A black body assembly is provided for use in the calibration of infrared cameras. The assembly includes, among other things, a housing within which calibration components may be situated, and a lens guide for accurately positioning the assembly over a lens of the infrared camera. A heat emitter may be positioned within the housing for emitting a necessary amount of heat for calibration purposes. A heating element may also be provided within the housing for controlling the heating and cooling of the heat emitter. The assembly may also include a heat sink to remove excessive heat generated from the thermoelectric cooler during temperature cycling. An arm may be employed to hingedly connect the assembly to the camera to provide reliable and repeatable way to position the black body assembly at the front of the infrared lens. A method for calibrating an infrared camera is also provided.

Abstract: The present invention discloses a portable blackbody furnace comprising a metallic body, a cylindrical cavity with a tapered end in the metallic body, a shielding plate positioned at an open end of the cylindrical cavity, at least a first heaters positioned in the shielding plate, a plurality of second heaters positioned around the metallic body, and a plurality of thermometers positioned in the metallic body. Preferably, the heat capacity of the metallic body is larger than 200 Joules/K, and has radial thickness larger than 5 mm. There are grooves formed on the outer wall of the metallic body, and the second heaters are heating wires embedded inside the grooves. In addition, the flow direction of the current between two adjacent heating wires is opposite to eliminate the magnetic field generated from the current flow.

Abstract: Calibrating temperature sensors of weathering devices by means of contactless temperature measurement A temperature sensor (10) which is, for example, designed as a black standard sensor and is typically used in apparatuses for artificial weathering of material samples, has in a known way a stainless steel plate (1) which is provided with a black coating (2) and is thermally coupled at its rear side to a platinum resistor (3). The output signal of the electric measurement transducer circuit connected to the platinum resistor (3) by means of feeder wires (4) can be calibrated with the surface temperature measured in a contactless fashion by a pyrometer (8). The calibration operation can be carried out under the conditions prevailing in a weathering device, that is to say while applying to the surface of the sensor the optical radiation of a xenon radiation source (7) and an airstream (9) parallel to the surface.

Abstract: An instrument measures the LED junction temperature directly by taking advantage of the linear relationship between the forward current driven through the LED, the forward drop of the LED, and the junction temperature to determine the LED junction temperature. Calibration is conducted by placing two LEDs from the same family in ambient temperature and passing a small test current through each of the LEDs to obtain the forward drop of the LED at ambient temperature. The LED under test is then placed in an environmentally-controlled chamber where the temperature is raised a known amount above ambient temperature. Known low and high voltage values are associated with the ambient temperature and the environmental chamber temperature, causing the LED under test becomes a calibrated thermometer that can measure its own junction temperature due to the linear relationship between the forward drop and the junction temperature.

Abstract: A temperature measurement apparatus allows for accurate temperature measurement in both the sun and the shade using two different thermal sensors. A black sensor has an infrared absorbent surface and a white sensor has an infrared reflecting surface. Using the measurements from these two sensors, a series of equations calculate the correct ambient temperature regardless of where the measurement device is located and ensures accurate readings using a performance check system.

Abstract: A temperature determining device is composed of a temperature detecting unit that detects a temperature of a determination object member based on an intensity of infrared rays from the object member, a unit for determining a temperature for correction that determines a temperature of an opposing member opposed to the object member or a temperature of a member whose temperature changes in correlation to a change in the temperature of the opposing member, and a calculating unit that corrects the detected temperature obtained by the temperature detecting unit using the temperature as the temperature for correction obtained by the unit for determining a temperature for correction. Thus, stable temperature determination can be performed accurately without being influenced by infrared rays from around a determination object member.

Abstract: 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.

Abstract: A turbo-molecular pump has components including a stator column, a rotary shaft, and a blade connected to the rotary shaft for rotation therewith. A radiation temperature measuring apparatus has a radiation thermometer for measuring a temperature of a preselected one of the components of the turbo-molecular pump disposed within a view angle range of the radiation thermometer and in accordance with heat energy radiated from the preselected component. A hood is connected to the radiation thermometer so as to not interfere with the view angle range of the radiation thermometer and is configured to block heat energy radiated from components of the turbo-molecular pump disposed outside of the view angle range of the radiation thermometer.

Abstract: The invention discloses a method for measuring the temperature of a molten steel continuously, comprises the following steps: providing a tube that is made of double bushings, both of the inner and outer bushings being close at one end and open at another end; putting the close end of the tube into the molten steel in such a way that the ratio of the length of the tube under the surface of the molten steel to the inner diameter of the inner bushing is equal or greater than 15 and the ratio of said length to the outer diameter of the outer bushing is greater than 3; connecting the open end of the tube with an infrared detector; and calculating the temperature of the molten steel through evaluating the radiation emitted by the inner bushing at the end that was put under the molten steel by means of the detector. A tube to implement the method is also disclosed.

Abstract: A temperature measuring method for a target substrate to be thermally processed in a semiconductor processing apparatus under a predetermined process condition is provided. This method includes the steps of detecting a heat flux supplied from at least part of the target substrate and detecting a temperature of a sensor by using the sensor facing the target substrate, and calculating a temperature of the target substrate from a parameter, including a thermal resistance between the sensor and the target substrate under the predetermined process condition, the detected heat flux, and the temperature of the sensor. The sensor is arranged opposite to heating means, through the target substrate, which heats the target substrate. The parameter may be obtained in advance by calibration.

Abstract: 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.

Abstract: A method for calibrating a total-power microwave radiometer for a satellite uses a cold calibration source, a hot calibration source and a receiver. The method has the steps of measuring with the receiver the brightness temperatures of the hot calibration source having a temperature of Thot1, the hot calibration source having a temperature of Thot2 where Thot1 and Thot2 are different temperatures, and the cold calibration source, calculating for these measured values the standard deviation &Dgr;Thot1, &Dgr;Thot2 and &Dgr;Tcold, and calibrating the total-power microwave radiometer for a satellite by defining the brightness temperature of the cold calibration source as: Tcold=[(&Dgr;Thot1−&Dgr;Tcold)Thot2−(&Dgr;Thot2−&Dgr;Tcold)Thot1]/(&Dgr;Thot1−&Dgr;Thot2). The method makes it possible to calibrate the colder part of the total-power microwave radiometer for a satellite frequently and accurately.

Abstract: An apparatus for calibration of temperature sensors, comprising a cavity (2) for receiving a sensor (10) to be calibrated, a heat-transferring medium (5) for surrounding the sensor in the cavity, and a means for heating/cooling of the medium to a desired temperature. The cavity (2) receives at least one sensor-surrounding thin-walled calibrator body (3) which is made of a pliable material having a high thermal conductivity and which defines a volume (4) which is filled of a heat-transferring medium, the calibrator body (3) having an inner wall (8) defining at least a part of an inner opening (9) for receiving at least one sensor (10), and being arranged to be subjected to a pressure influence to bring the opening-defining wall (8) of the calibrator body into tight-fitting abutment against the sensor (10) or sensors.

Abstract: It is difficult to test gas detectors that are difficult to access. The test device according to the invention is functionally linked with the gas detector or with the heat detector and substantially simplifies testing of such detectors.

Abstract: A process for thermal imaging scanning of a swaged heater of an anode subassembly of a hollow cathode assembly, comprising scanning a swaged heater with a thermal imaging radiometer to measure a temperature distribution of the heater; raising the current in a power supply to increase the temperature of the swaged heater; and measuring the swaged heater temperature using the radiometer, whereupon the temperature distribution along the length of the heater shall be less than plus or minus 5 degrees C.

Abstract: Methods and systems are disclosed for detecting overheating in an optical device before harmful consequences, such as severe local heating, can result. In one embodiment of the invention, a blackbody emitter is disposed in close proximity to a therapeutic optical fiber to absorb therapeutic radiation at a fault and re-emit blackbody (infrared) radiation. The emitter can be coupled to the fiber but, during normal operation, lies outside the optical path between the output of the laser radiation and the site of treatment. Systems and catheters incorporating such emitters are also described for effective monitoring of the laser power transmitted along the optical fiber within the phototherapy device.

Abstract: 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.

Abstract: A self-calibrating nulling radiometer for non-contact temperature measurement of an object, such as a body of water, employs a black body source as a temperature reference, an optomechanical mechanism, e.g., a chopper, to switch back and forth between measuring the temperature of the black body source and that of a test source, and an infrared detection technique. The radiometer functions by measuring radiance of both the test and the reference black body sources; adjusting the temperature of the reference black body so that its radiance is equivalent to the test source; and, measuring the temperature of the reference black body at this point using a precision contact-type temperature sensor, to determine the radiative temperature of the test source.