Rotational temperature measurements 300 deg K to 1000 deg K with electron beam probe
Laboratory measurements of rotational temperatures in static low density air with electron beam probe
Hunter, W. W., Jr.↗
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Airborne pressure and temperature measurements during the 1977 intertropical convergence zone experiment
During the 1977 ITCZ (Intertropical Convergence Zone) experiment in Panama two aircraft and numerous balloon-borne radiosonde instruments were equipped to measure pressure and temperature. The experiment was a coordinated effort to evaluate the meteorological conditions that prevailed from July 17 through 31, 1977. A critical analysis of the data collected on one of the aircraft (the Lear jet) operating at altitudes to 13,000 m for about 2 hr each day during most days of the experiment is presented. The discussion includes a comparison of the vertical profiles of potential temperature obtained from the Learjet with those obtained from balloons launched at Ft. Sherman. Time histories of pressure, temperature, and potential temperature, as observed from the Learjet are also presented.
Munoz, R. M.↗
Some 20.7- and 31.4-GHz solar disk temperature measurements
The performance of a 20.7/31.4 GHz water vapor radiometer was evaluated with respect to its use in measuring atmospheric noise temperature. Results are in good agreement with the results previously reported at the same frequency.
Franco, M. M.↗
A Novel, High Resolution, Non-Contact Channel Temperature Measurement Technique
An in-situ optical technique based on infrared emission spectroscopy has been developed for non-contact measurement of the temperature of a hot spot in the gate channel of a GaAs metal/semiconductor field effect transistor (MESFET).
temperature optical technique infrared MESFET↗
Floating Probe Assembly for Measuring Temperature of Water
A floating apparatus denoted a temperature probe aquatic suspension system (TPASS) has been developed for measuring the temperature of an ocean, lake, or other natural body of water at predetermined depths. Prior instruments built for the same purpose were found to give inaccurate readings because the apparatuses themselves significantly affected the temperatures of the water in their vicinities. The design of the TPASS is intended to satisfy a requirement to minimize the perturbation of the temperatures to be measured. The TPASS includes a square-cross-section aluminum rod 28 in. (approx. = 71 cm) long with floats attached at both ends. Each float includes five polystyrene foam disks about 3/4 in. (approx. = 1.9 cm) thick and 2.5 in. (approx. = 6.4 cm) in diameter. The disks are stacked to form cylinders, bolted to the rod, and covered with hollow plastic sleeves. A metal sleeve is clamped to the middle of the aluminum rod, from whence it hangs down into the water. Temperature probes (which can be thermocouples, thermistors, or resistance temperature devices) are placed within the sleeve at the desired measurement depths. Wires from the temperature probes are routed to the input terminals of a data logger. This work was done by Randy
Selinsky, T.↗
One dimensional temperature measurements by resonantly ionized photoemission thermometry of molecular nitrogen
This paper presents an extensive parameter study of a non-intrusive and non-seeded laser diagnostic method for measuring one dimensional (1D) rotational temperature of molecular nitrogen (N 2 ) at 165 - 450 K. Compared to previous efforts using molecular oxygen, here resonantly ionized and photoelectron induced fluorescence of molecular nitrogen for thermometry (N 2 RIPT) was demonstrated. The RIPT signal is generated by directly probing various rotational levels within the rovibrational absorption band of N 2 , corresponding to the 3-photon transition of N 2 ( X 1 Σ g + , v =0→ b 1 Π u , v ′ =6) near 285 nm, without involving collisional effects of molecular oxygen and nitrogen. The photoionized N 2 produces strong first negative band of N 2 + ( B 2 Σ u + − X 2 Σ g + ) near 390 nm, 420 nm, and 425 nm. Boltzmann analyses of various discrete fluorescence emission lines yield rotational temperatures of molecular nitrogen. By empirically choosing multiple rotational levels within the absorption band, non-scanning thermometry can be accurately achieved for molecular nitrogen. It is demonstrated that the N 2 RIPT technique can measure 1D temperature profile up to ∼5 cm in length within a pure N 2 environment. Multiple wavelengths are thoroughly analyzed and listed that are accurate for RIPT for various temperature ranges.
McCord, Walker (ORCID:0000000179747550)↗
Fabrication and Testing of a Stainless Steel Quartz Coaxial Cable Structure for High Temperature Measurement
This paper presents a stainless-steel quartz coaxial cable structure for distributed sensing of high temperatures. The coaxial cable sensor uses stainless steel as the inner and outer conductors and quartz as the insulator in order to achieve mechanical strength and temperature resilience. Girdle-shaped reflectors are fabricated on the quartz tubing by CNC grinding and CO 2 laser resurfacing. The sensor operates by measuring the temperature dependent change in the effective electromagnetic length between the two adjacent reflectors on the quartz tubing. A retaining collar is fabricated at the tip of the quartz tubing by 3D printing and laser resurfacing to secure the connection between the sensor and the signal cable. The prototype sensor was tested for high temperature measurements up to 600°C, and the performance characteristics of the sensor such as sensitivity, resolution uncertainty, repeatability, and stability were estimated based on the test results.
Jiao, Xinyu↗
Comparison of predicted and measured temperatures of UH-60A helicopter transmission
The 2109-kW (2828-hp) UH-60A Black Hawk helicopter transmission was one of the transmissions used to obtain an experimental data base. Component improvements or new transmission concepts can thus be evaluated by comparison with the established data. Results of efficiency and vibration tests of the UH-60A have been reported previously. In this investigation the transmission was instrumented internally and tested over a range of operating conditions. The speed was varied from 50 to 100 percent of the full rated value, and the torque was varied from 10 to 100 percent of the full rated value. Temperatures of internal bearings and gears were measured. The computer program Planetsys was used to simulate the thermal performance of this transmission. The calculated temperatures were then compared with the corresponding measured values. The highest measured temperature was 405 K (270 F) on the outer race of the high-speed input shaft roller bearing, at the 100-percent power condition. In general, the predicted temperatures compared very well with the measured values, most of them being within 5 kelvin (9 F). Specifically, the temperatures predicted for the single-row spherical roller planetary bearing averaged only about 4 kelvin (8 F) lower than the highest measured value.
Coe, Harold H.↗
Temperature Measurement of Ceramic Materials Using a Multiwavelength Pyrometer
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 because of their complex optical properties, such as low emissivity which varies with both temperature and wavelength. In at least one of the materials, yittria, the detected optical emission increased as the temperature was decreased due to such emissivity variation. The reasons for such changes are not known. The multiwavelength pyrometer has demonstrated its ability to measure surface temperatures under such conditions. Platinum electrodes were embedded in the ceramic pellets for resistance measurements as the temperature changed.
Ng, Daniel↗
An update on remote measurement of soil moisture over vegetation using infrared temperature measurements: A FIFE perspective
Using model development, image analysis and micrometeorological measurements, the object is to push beyond the present limitations of using the infrared temperature method for remotely determining surface energy fluxes and soil moisture over vegetation. Model development consists of three aspects: (1) a more complex vegetation formulation which is more flexible and realistic; (2) a method for modeling the fluxes over patchy vegetation cover; and (3) a method for inferring a two-layer soil vertical moisture gradient from analyses of horizontal variations in surface temperatures. HAPEX and FIFE satellite data will be used along with aircraft thermal infrared and solar images as input for the models. To test the models, moisture availability and bulk canopy resistances will be calculated from data collected locally at the Rock Springs experimental field site and, eventually, from the FIFE project.
Carlson, Toby N.↗
Pressure-volume-temperature measurements on hydrogen from 200 deg to 600 deg C and up to 1800 atmospheres
Pressure-volume-temperature measurements on H, calculating fugacity coefficients
Presnall, D. C.↗
Influence of Assimilation of Subsurface Temperature Measurements on Simulations of Equatorial Undercurrent and South Equatorial Current Along the Pacific Equator
Equatorial Pacific current and temperature fields were simulated with and without assimilation of subsurface temperature measurements for April 1992 - March 1995, and compared with moored bouy and research vessel current measurements.
TemperatureUndercurrent Equatorial current Pacific↗
Evidence for Surface Water Ice in the Lunar Polar Regions Using Reflectance Measurements from the Lunar Orbiter Laser Altimeter and Temperature Measurements from the Diviner Lunar Radiometer Experiment
We find that the reflectance of the lunar surface within 5 deg of latitude of theSouth Pole increases rapidly with decreasing temperature, near approximately 110K, behavior consistent with the presence of surface water ice. The North polar region does not show this behavior, nor do South polar surfaces at latitudes more than 5 deg from the pole. This South pole reflectance anomaly persists when analysis is limited to surfaces with slopes less than 10 deg to eliminate false detection due to the brightening effect of mass wasting, and also when the very bright south polar crater Shackleton is excluded from the analysis. We also find that south polar regions of permanent shadow that have been reported to be generally brighter at 1064 nm do not show anomalous reflectance when their annual maximum surface temperatures are too high to preserve water ice. This distinction is not observed at the North Pole. The reflectance excursion on surfaces with maximum temperatures below 110K is superimposed on a general trend of increasing reflectance with decreasing maximum temperature that is present throughout the polar regions in the north and south; we attribute this trend to a temperature or illumination-dependent space weathering effect (e.g. Hemingway et al. 2015). We also find a sudden increase in reflectance with decreasing temperature superimposed on the general trend at 200K and possibly at 300K. This may indicate the presence of other volatiles such as sulfur or organics. We identified and mapped surfaces with reflectances so high as to be unlikely to be part of an ice-free population. In this south we find a similar distribution found by Hayne et al. 2015 based on UV properties. In the north a cluster of pixels near that pole may represent a limited frost exposure.
Emily A Fisher↗
Temperature measurement using infrared imaging systems during turbine engine altitude testing
This report details the use of infrared imaging for temperature measurement and thermal pattern determination during simulated altitude engine testing in the NASA Lewis Propulsion Systems Laboratory. Three identical argon-cooled imaging systems were installed in the facility exhaust collector behind sapphire windows to look at engine internal surfaces. The report describes the components of each system, presents the specifics of the complicated installation, and explains the operation of the systems during engine testing. During the program, several problems emerged, such as argon contamination system, component overheating, cracked sapphire windows, and other unexplained effects. This report includes a summary of the difficulties as well as the solutions developed. The systems performed well, considering they were in an unusually harsh exhaust environment. Both video and digital data were recorded, and the information provided valuable material for the engineers and designers to quickly make any necessary design changes to the engine hardware cooling system. The knowledge and experience gained during this program greatly simplified the installation and use of the systems during later test programs in the facility. The infrared imaging systems have significantly enhanced the measurement capabilities of the facility, and have become an outstanding and versatile testing resource in the Propulsion Systems Laboratory.
Burns, Maureen E.↗
Systems and methods of adaptive two-wavelength single-camera imaging thermography (ATSIT) for accurate and smart in-situ process temperature measurement during metal additive manufacturing
A two-wavelength, single-camera imaging thermography system for in-situ temperature measurement of a target, comprising: a target light path inlet conduit for receiving a target light beam reflected from the target; a beam splitter installed in a splitter housing at a distal end of the target light path conduit, wherein the beam splitter divides the target light beam into a first light beam and a second light beam; a first light path conduit emanating from the splitter housing comprising a first aperture iris installed within the first light path conduit for aligning the first light beam; a first band pass filter installed within the first light path conduit for regulating the first light beam to a first wavelength λ1 and an optional half waveplate installed within the first light path conduit to modulate a polarization ratio of the first light beam of λ1 wavelength; a second light path conduit emanating from the splitter housing comprising a second aperture iris installed within the second light path conduit for aligning the second light beam; a second band pass filter installed within the second light path conduit for regulating the second light beam to a second wavelength λ2; a junction housing, wherein distal ends of each of the first and second light path conduits are connected to the junction housing; a polarizing beam splitter installed in the junction housing, wherein the polarizing beam splitter reflects the first light beam of λ1 wavelength along the same path or a parallel path of the second light beam of λ2 wavelength that passes directly through the polarizing beam splitter unreflected to create a merged light beam comprising light of λ1 and λ2 wavelengths; and a light path outlet conduit connected to the junction for directing the merged beam to a high-speed camera for imaging.
Zhao, Xiayun↗
A method for measuring temperatures and densities in hypersonic wind tunnel air flows using laser-induced O2 fluorescence
Laser-induced fluorescence in oxygen, in combination with Raman scattering, is shown to be an accurate means by which temperature, density, and their fluctuations due to turbulence can be measured in air flows associated with high-speed wind tunnels. For temperatures above 60 K and densities above 0.01 amagat, the uncertainty in the temperature and density measurements can be less than 2 and 3 percent, respectively, if the signal uncertainties are dominated by photon-statistical noise. The measurements are unaffected by collisional quenching and can be achieved with laser fluences for which nonlinear effects are insignificant. Temperature measurements using laser-induced fluorescence alone have been demonstrated at known densities in the range of low temperatures and densities which are expected in a hypersonic wind tunnel.
Laufer, Gabriel↗
Method for measuring temperatures and densities in hypersonic wind tunnel air flows using laser-induced O2 fluorescence
Laser-induced fluorescence in oxygen, in combination with Raman scattering, is shown to be an accurate means by which temperature, density, and their fluctuations owing to turbulence can be measured in air flows associated with high-speed wind tunnels. For temperatures above 60 K and densities above 0.01 amagat, the uncertainties in the temperature and density measurements can be less than 2 percent, if the signal uncertainties are dominated by photon statistical noise. The measurements are unaffected by collisional quenching and can be achieved with laser fluences for which nonlinear effects are insignificant. Temperature measurements using laser-induced fluorescence alone have been demonstrated at known densities in the range of low temperatures and densities which are expected in a hypersonic wind tunnel.
Laufer, Gabriel↗
Tungsten-rhenium alloy thermocouples effective for high-temperature measurement
Tungsten-rhenium alloy thermocouples, specifically, insulated, sheathed W/W plus 26Re and W plus 5 Re/W plus 26 Re thermocouples, are effective for temperature measurement in excess of 2920 degrees C. These thermocouples have a high thermoelectric output and excellent relationship to temperatures up to 2760 degrees C.
Brooks, E. J.↗