A laser pyrometer was developed for acquiring the true temperature of a levitated sample. The reflectivity is measured by first expanding the laser beam to cover the entire cross-sectional surface of the diffuse target. The reflectivity calibration of this system is determined from the surface emissivity of a target with a blackbody cavity. The emissivity of the real target can then be calculated. The overall system constant is obtained by passively measuring the radiance of the blackbody...
Topics: NASA Technical Reports Server (NTRS), LASER APPLICATIONS, RADIATION PYROMETERS, TEMPERATURE...
Design and operation of accurate millisecond and microsecond resolution optical pyrometers developed at the National Bureau of Standards during the last two decades are described. Results of tests are presented and estimates of uncertainties in temperature measurements are given. Calibration methods are discussed and examples of applications of fast pyrometry are given. Ongoing research in developing fast multiwavelength and spatial scanning pyrometers are summarized.
Topics: NASA Technical Reports Server (NTRS), OPTICAL PYROMETERS, RADIATION PYROMETERS, TEMPERATURE...
Noncontact temperature measurement has been identified as one of the eight advanced technology development (ATD) areas to support the effort of the Microgravity Science and Applications Division in developing six Space Station flight experiment facilities. This two-day workshop was an opportunity for all six disciplines to present their requirements on noncontact temperature measurement and to discuss state-of-the-art developments. Multi-color pyrometry, laser pyrometry and radiometric imaging...
Topics: NASA Technical Reports Server (NTRS), CONFERENCES, INFRARED RADIOMETERS, OPTICAL PYROMETERS,...
Early measurements of the solar constant are described and discussed with particular emphasis on the Smithsonian program. A brief description is given of the monitoring program currently operating at San Diego State.
Topics: NASA Technical Reports Server (NTRS), SOLAR CONSTANT, TEMPERATURE MEASUREMENT, BOLOMETERS, PARTICLE...
Topics: DTIC Archive, Foote, Paul D, NATIONAL BUREAU OF STANDARDS GAITHERSBURG MD, *TEMPERATURE, *HIGH...
The most common sources of error in optical pyrometry are examined. They can be classified as either noise and uncertainty errors, stray radiation errors, or speed-of-response errors. Through judicious choice of detectors and optical wavelengths the effect of noise errors can be minimized, but one should strive to determine as many of the system properties as possible. Careful consideration of the optical-collection system can minimize stray radiation errors. Careful consideration must also be...
Topics: NASA Technical Reports Server (NTRS), INSTRUMENT ERRORS, OPTICAL PYROMETERS, RADIATION PYROMETERS,...
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199
Jun 1, 2010
06/10
by
Voytikova, T. D
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Radiation coefficient calculation of black hemispherical radiator for calibrating pyrgeometers
Topics: BLACK BODY RADIATION, CALIBRATING, RADIATION MEASURING INSTRUMENTS, RADIATION PYROMETERS,...
Atomics International, Canoga Park, Calif. THERMAL PROPERTIES OF REFRACTORY MATERIALS, by J. A. Cape and R. E. Taylor. Quarterly progress rept. no. 3, 1 Feb-30 Apr 1961 on Materials Thermal Properties. 30 Apr 1961, 21p. incl. illus. tables. (Contract AF 33(616)6794, Proj. 4776) (ARPA Order no. 24-59) Unclassified report. The thermal conductivity of TiC was measured over the temperature region 400 to 1200 deg C by the steady state radial heat flow method. The conductivity varies linearly from...
Topics: DTIC Archive, Cape, J A, ATOMICS INTERNATIONAL CANOGA PARK CA, *HEAT TRANSFER, *HIGH TEMPERATURE,...
A radiation pyrometer for measuring the true temperature of a body is provided by detecting and measuring thermal radiation from the body based on the principle that the effects of angular emission I(sub 1) and reflection I(sub 2) on the polarization states p and s of radiation are complementary such that upon detecting the combined partial polarization state components I(sub p) = I(sub 1p) + I(sub 2p) and I(sub s) = I(sub 1s) + I(sub 2s) and adjusting the intensity of the variable radiation...
Topics: NASA Technical Reports Server (NTRS), BRIGHTNESS TEMPERATURE, POLARIZATION (WAVES), RADIATION...
Temperature measurement is an essential capability for almost all areas of metals and alloys research. In the microgravity environment many of the science priorities that have been identified for metals and alloys also require noncontact temperature measurement capability. For example, in order to exploit the full potential of containerless processing, it is critical to have available a suitable noncontact temperature measurement system. This system is needed to track continuously the thermal...
Topics: NASA Technical Reports Server (NTRS), ALLOYS, METALS, SPACE PROCESSING, TEMPERATURE MEASUREMENT,...
243
243
Jul 23, 2010
07/10
by
Nystrom, George U
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This report studies modification of existing balloon gimbal designs for use on the Gamma Ray Imaging device experiment. Improved bearings and brushless torque motors are required to lower bearing torque noise and meet stringent pointing requirements. Analytical results from a strawman gondola and control system design show that pointing requirements are satisfied.
Topics: CONFERENCES, LASER SPECTROSCOPY, MICROGRAVITY APPLICATIONS, SPACE COMMERCIALIZATION, SPACE...
Temperature measurement of small (millimeter size) objects is generally difficult and demanding. Measurement involving ceramic materials using the traditional one- and two-color pyrometer is difficult because of their complex optical properties, such as low emissivity which may vary with both temperature and wavelength. Pyrometry applications in an environment with an interfering radiation source of extended dimension adds extra complexity to the process. We show that the multiwavelength...
Topics: NASA Technical Reports Server (NTRS), TEMPERATURE MEASUREMENT, CERAMICS, RADIATION SOURCES,...
Design engineering work on the next generation solventless propellant mechanized rolling facilities was conducted. Design criteria was developed and submitted to the Corps of Engineers so that the updated facility could be constructed. Results of plant-scale evaluations of proposed process changes are discussed. Specifications and design criteria on the major production equipment are also included.
Topics: DTIC Archive, Montgomery, James A, SUNFLOWER ARMY AMMUNITION PLANT LAWRENCE KS, *ROLLING MILLS,...
A method of determining the emissivity of a hot target from a laser-based reflectance measurement which is conducted simultaneously with a measurement of the target radiance is described. Once the correct radiance and emissivity are determined, one calculates the true target temperature from these parameters via the Planck equations. The design and performance of a laser pyrometer is described. The accuracy of laser pyrometry and the effect of ambient radiance are addressed.
Topics: NASA Technical Reports Server (NTRS), EMISSIVITY, LASER APPLICATIONS, RADIATION PYROMETERS,...
The relationship between the optical properties of glass and temperature measurements in it by radiation pyrometry are described. Equations for the calculation of emissivity are presented and the transmittance, surface reflection and absorption characteristics of glass are defined. Recommendations are given regarding the selection of pyrometer wavelength sensitivity and the use of a blackbody radiator.
Topics: NASA Technical Reports Server (NTRS), GLASS, RADIATION PYROMETERS, TEMPERATURE MEASUREMENT,...
A specular, spherical, or near-spherical target is located within a furnace having inner walls and a viewing window. A pyrometer located outside the furnace 'views' the target through pyrometer optics and the window, and it is positioned so that its detector sees only the image of the viewing window on the target. Since this image is free of any image of the furnace walls, it is free from wall radiance, and correction-free target radiance is obtained. The pyrometer location is determined...
Topics: NASA Technical Reports Server (NTRS), IMAGE FURNACES, RADIATION PYROMETERS, RAY TRACING,...
A method and apparatus for detecting the temperature of gray and non-gray bodies in the presence of interfering radiation are presented. A gray body has a constant emissivity less than 1 and a non-gray body has an emissivity which varies with wavelength. The emissivity and reflectivity of the surface is determined over a range of wavelengths. Spectra are also measured of the extraneous interference radiation source and the surface of the object to be measured in the presence of the extraneous...
Topics: NASA Technical Reports Server (NTRS), ELECTROMAGNETIC INTERFERENCE, EMISSIVITY, OPTICAL PYROMETERS,...
A radiation pyrometer for measuring the true temperature of a body is provided by detecting and measuring thermal radiation from the body based on the principle that the effects of angular emission I(sub 1) and reflection I(sub 2) on the polarization states p and s of radiation are complementary such that upon detecting the combined partial polarization state components I(sub p) =I(sub 1p) + I(sub 2p) and I(sub s)=I(sub 1s) + I(sub 2s) and adjusting the intensity of the variable radiation...
Topics: NASA Technical Reports Server (NTRS), EMITTANCE, LIGHT SOURCES, RADIATION PYROMETERS, PATENTS,...
Optical pyrometry provides a means for non-contact temperature measurements whose accuracy depends on the accuracy with which specimen emittance is known. Two methods for obtaining the required emittance data are discussed in which the emittance is determined from measurements of the wavelength or polarization dependence of light emitted by the specimen. The spectral technique, multi-color pyrometry, yields apparent values for specimen emittance and temperature from emitted intensity...
Topics: NASA Technical Reports Server (NTRS), EMISSIVITY, LIQUIDS, OPTICAL PYROMETERS, RADIATION...
A multicolor imaging pyrometer was designed for accurately and precisely measuring the temperature distribution histories of small moving samples. The device projects six different color images of the sample onto a single charge coupled device array that provides an RS-170 video signal to a computerized frame grabber. The computer automatically selects which one of the six images provides useful data, and converts that information to a temperature map. By measuring the temperature of molten...
Topics: NASA Technical Reports Server (NTRS), COLOR, RADIATION PYROMETERS, SURFACE TEMPERATURE, TEMPERATURE...
Various methods and devices for obtaining experimental data on heat flux density over wide ranges of temperature and pressure are examined. Laboratory tests and device fabrication details are supplemented by theoretical analyses of heat-conduction and thermoelectric effects, providing design guidelines and information relevant to further research and development. A theory defining the measure of correspondence between transducer signal and the measured heat flux is established for individual...
Topics: NASA Technical Reports Server (NTRS), FLUX DENSITY, HEAT FLUX, HEAT MEASUREMENT, TEMPERATURE...
197
197
Jul 12, 2010
07/10
by
Sweigart, A. V
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A sequence of solar models has been constructed in order to investigate the sensitivity of the solar radius and luminosity to small changes in the ratio alpha of the mixing length lambda to the pressure-scale height Hp throughout the solar convective envelope. The basic procedure for determining this sensitivity was to impose a perturbation in alpha within the convective envelope and then to follow the resulting changes in the solar radius delta R and luminosity delta L for the next 10 to the...
Topics: SOLAR CONSTANT, TEMPERATURE MEASUREMENT, BOLOMETERS, PARTICLE FLUX DENSITY, RADIATION PYROMETERS
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200
May 6, 2010
05/10
by
Buchele, D. R
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Nonlinear averaging errors in radiation pyrometry
Topics: AVERAGE, ERRORS, NONLINEARITY, RADIATION PYROMETERS, TEMPERATURE MEASUREMENT, ERROR, RADIATION...
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619
Jul 12, 2010
07/10
by
Davis, R. F
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The results of an effort to document methods for accomplishing response predictions for commonly encountered aerospace structural configurations is presented. Application of these methods to specified aerospace structure to provide sample analyses is included. An applications manual, with the structural analyses appended as example problems is given. Comparisons of the response predictions with measured data are provided for three of the example problems.
Topics: FLUX DENSITY, REACTOR PHYSICS, HEAT FLUX, HEAT MEASUREMENT, TEMPERATURE MEASUREMENT, TRANSDUCERS,...
The NASA self calibrating multiwavelength pyrometer is a recent addition to the list of pyrometers used in remote temperature measurement in research and development. The older one-color, two-color, and the disappearing filament pyrometers, as well as the multicolor and early multiwavelength pyrometers, all do not operate successfully in situations in which strong ambient radiation coexists with radiation originating from the measured surface. In such situations radiation departing from the...
Topics: NASA Technical Reports Server (NTRS), CALIBRATING, REMOTE SENSORS, TEMPERATURE MEASUREMENT,...
462
462
May 22, 2011
05/11
by
Pien, Home
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During GFY 91, Draper Laboratory was awarded a task by NASA-JSC under contract number NAS9-18426 to study and evaluate the potential for achieving safe autonomous landings on Mars using an on-board autonomous hazard detection and avoidance (AHDA) system. This report describes the results of that study. The AHDA task had four objectives: to demonstrate, via a closed-loop simulation, the ability to autonomously select safe landing sites and the ability to maneuver to the selected site; to...
Topics: ELECTROMAGNETIC INTERFERENCE, EMISSIVITY, OPTICAL PYROMETERS, RADIATION DETECTORS, RADIATION...
The design, construction and calibration of a computer-linked multicolor pyrometer is described. The device was constructed for ready adaptation to a spacecraft and for use in the control of thermal processes for manufacturing materials in space. The pyrometer actually uses only one color at a time, and is relatively insensitive to uncertainties in the heated object's emissivity because the product of the color and the temperature has been selected to be within a regime where the radiant energy...
Topics: NASA Technical Reports Server (NTRS), RADIATION PYROMETERS, SPACE PROCESSING, TEMPERATURE CONTROL,...
Current efforts of the Microgravity Combustion Working Group are summarized and the temperature measurement requirements for the combustion studies are defined. Many of the combustion systems that are studied in the low gravity environment are near-limit systems, that is, systems that are acting near the limit of flammability in terms of oxygen concentration or fuel concentration. Systems of this type are normally weak in the sense that there is a delicate balance between the heat released in...
Topics: NASA Technical Reports Server (NTRS), COMBUSTION PHYSICS, MICROGRAVITY, SPACEBORNE EXPERIMENTS,...
The report describes an experimental program performed to generate technology on high temperature sensor concepts for small gas turbines. Major emphasis was placed on the definition of material systems needed for transducers with long life, good reliability, and fast response for sensing turbine inlet temperatures in the range of 2200 to 2500F with transients to 3000F. The technology related to three types of sensors was considered; thermocouples, resistive devices, and radiation pyrometers....
Topics: DTIC Archive, Gaylord, A M, SOLAR TURBINES INTERNATIONAL SAN DIEGO CA, *GAS TURBINES, *RADIATION...
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111
Jul 23, 2010
07/10
by
Ivakhnenko, A. G
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No Abstract Available
Topics: GASES, PHOTOCONDUCTORS, HIGH PRESSURE, INFRARED RADIATION, PHOTOELECTRIC CELLS, PRESSURE VESSELS,...
Surface pyrometry is feasible even when the amount of surface radiation is exceeded by radiation from surrounding sources. To measure and correct for this interfering radiation, several methods that use multiple wavelength pyrometry were compared by an error analysis. For a specific application to turbine blade temperature measurement in a turbofan engine, a two wavelength method was best. Auxiliary measurements at the same wavelengths substantially improve the accuracy of the method.
Topics: NASA Technical Reports Server (NTRS), RADIATION PYROMETERS, THERMOCOUPLE PYROMETERS, TURBINE...
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232
May 27, 2011
05/11
by
Lynch, Kristina A
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Research supported by this grant covered two main topics: auroral ion acceleration from ELF-band wave activity, and from VLF-spikelet (lower hybrid solitary structure) wave activity. Recent auroral sounding rocket data illustrate the relative significance of various mechanisms for initiating auroral ion outflow. Two nightside mechanisms are shown in detail. The first mechanism is ion acceleration within lower hybrid solitary wave events. The new data from this two payload mission show clearly...
Topics: TEMPERATURE MEASUREMENT, EMISSIVITY, MAGNESIUM OXIDES, YTTRIUM OXIDES, PARABOLOID MIRRORS,...
A turbine blade temperature measuring system for liquid oxygen turbopumps is reported. The system includes a three mode, two-input optical signal processor, interconnecting cable, and four sensor heads. Two of the heads are aperture type, while the other two are lens type. This system is applicable to a temperature range of 1400 to 2200 F.
Topics: NASA Technical Reports Server (NTRS), HIGH TEMPERATURE GASES, OPTICAL PYROMETERS, RADIATION...
The use of optical fibers in conjunction with infrared detectors and signal processing electronics represents the latest advance in the field of non-contact temperature measurement and control. The operating principles and design of fiber-optic radiometric systems are discussed and the advantages and disadvantages of using optical fibers are addressed. Signal processing requirements and various infrared detector types are also described. Several areas in which infrared fiber-optic...
Topics: NASA Technical Reports Server (NTRS), FIBER OPTICS, INFRARED RADIOMETERS, RADIATION PYROMETERS,...
A method is described for determining surface temperature in the presence of radiation being reflected by the surface of interest from another nearby hot surface. Radiance measurements are made on the surface of interest and on the nearby hot object in three different wavelength bands (three colors). If the emittance of the target surface varies significantly with wavelength, it is necessary to know the ratios of emittances in the three wavelength bands. An experiment was performed to...
Topics: DTIC Archive, Jackson, A G, ARNOLD ENGINEERING DEVELOPMENT CENTER ARNOLD AFB TN, *INFRARED...
Topics: DTIC Archive, TANDLER, WILLIAM S., TOURIN, RICHARD H., GROSSMAN, MORRIS, WARNER AND SWASEY RESEARCH...
This document is a two-part course on the theory and practice of radiation thermometry. Radiation thermometry is the technique for determining the temperature of a surface or a volume by measuring the electromagnetic radiation it emits. This course covers the theory and practice of radiative thermometry and emphasizes the modern application of the field using commercially available electronic detectors and optical components. The course covers the historical development of the field, the...
Topics: NASA Technical Reports Server (NTRS), ELECTROMAGNETIC RADIATION, TEMPERATURE MEASUREMENT,...
An overview of the theory and techniques of radiometric thermometry is presented. The characteristics of thermal radiators (targets) are discussed along with surface roughness and oxidation effects, fresnel reflection and subsurface effects in dielectrics. The effects of the optical medium between the radiating target and the radiation thermometer are characterized including atmospheric effects, ambient temperature and dust environment effects and the influence of measurement windows. The...
Topics: NASA Technical Reports Server (NTRS), INFRARED RADIOMETERS, RADIATION PYROMETERS, TEMPERATURE...
The requirements for non-contact temperature measurement capabilities for electronic materials processing in space are assessed. Non-contact methods are probably incapable of sufficient accuracy for the actual absolute measurement of temperatures in most such applications but would be useful for imaging in some applications.
Topics: NASA Technical Reports Server (NTRS), CRYSTAL GROWTH, SEMICONDUCTORS (MATERIALS), SPACE PROCESSING,...
The surface temperatures of several pure ceramic materials (alumina, beryllia, magnesia, yittria and spinel) in the shape of pellets were measured using a multiwavelength pyrometer. In one of the measurements, radiation signal collection is provided simply by an optical fiber. In the other experiments, a 4.75 inch (12 cm) parabolic mirror collects the signal for the spectrometer. Temperature measurement using the traditional one- and two-color pyrometer for these ceramic materials is difficult...
Topics: NASA Technical Reports Server (NTRS), TEMPERATURE MEASUREMENT, CERAMICS, SURFACE TEMPERATURE,...
The program of activities within the Microgravity Fluids and Transport Phenomena Discipline has been structured to enable the systematic pursuit of an increased understanding of low gravity fluid behavior/phenomena in a way which ensures that the results are appropriate to the widest range of applications. This structure is discussed and an overview of some of the activities which are underway is given. Of significance is the fact that in the majority of the current and planned activities, the...
Topics: NASA Technical Reports Server (NTRS), FLUID DYNAMICS, MICROGRAVITY, SPACEBORNE EXPERIMENTS,...
Flame temperatures in nonsooting and sooting environments were successfully measured by radiometry for pre-mixed propane-oxygen laminar flames stabilized on a water-cooled, porous sintered-bronze burner. The measured temperatures in the nonsooting flames were compared with fine-wire thermocouple measurements. The results show excellent agreement below 1700 K, and when the thermocouple measurements were corrected for radiation effects, the agreement was good for even higher temperatures. The...
Topics: NASA Technical Reports Server (NTRS), COMBUSTION TEMPERATURE, FLAME TEMPERATURE, GAS TEMPERATURE,...
Temperature measurement of a substance that is transparent using the traditional 1-color, 2-color and other pyrometers has been difficult. The radiation detected by pyrometers do not come from a well defined location in the transparent body. The multiwavelength pyrometer developed at the NASA Lewis Research Center can measure the surface temperature of many materials. We show in this paper that it also measures the surface and a bulk subsurface temperature of transparent materials like glass.
Topics: NASA Technical Reports Server (NTRS), GLASS, COLOR, RADIATION PYROMETERS, PYROMETALLURGY,...
The primary purpose of this evaluation was to determine if the Raytek IR pyrometer that was installed in the 600 gallon propellant mixers could be used to provide a continuous, accurate, reliable measurement of the propellant temperature during mixing. The Raytek infrared sensor is not recommended to be used for controlling propellant temperature nor for inspection buy-off. The first part of the evaluation was to determine the accuracy of the sensor in measuring the propellant temperature. The...
Topics: NASA Technical Reports Server (NTRS), INFRARED DETECTORS, INFRARED WINDOWS, MIXERS, RADIATION...
Studies were made in the design of a temperature reference unit, incorporating a vacuum system with a sighting window, for temperatures ranging from 1200 K to 2100 K. In view of the many variables present, the design study was supplemented with analytical and experimental data. Included in this work were transmittance studies of different sighting windows for blackbody radiation, the study of thermal shielding, and experimental studies of blackbody radiation. The window materials available...
Topics: DTIC Archive, ARMY MATERIALS RESEARCH AGENCY WATERTOWN MA, *TEMPERATURE SENSITIVE ELEMENTS,...
