A high-speed imaging pyrometer was developed to investigate the behavior of flames and explosive events. The instrument consists of two monochrome high-speed Phantom v7.3 m cameras made by Vision Research Inc. arranged so that one lens assembly collects light for both cameras. The cameras are filtered at 700 or 900 nm with a 10 nm bandpass. The high irradiance produced by blackbody emission combined with variable shutter time and f-stop produces properly exposed images. The wavelengths were chosen with the expected temperatures in mind, and also to avoid any molecular or atomic gas phase emission. Temperatures measured using this pyrometer of exploded TNT charges are presented.
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http://dx.doi.org/10.1364/AO.50.006267 | DOI Listing |
Materials (Basel)
June 2024
Department of Process Technique, Faculty of Manufacturing Technologies with a Seat in Presov, Technical University of Kosice, Bayerova 1, 080 01 Presov, Slovakia.
The long-term use of steel strip in various industries makes it an important semi-finished product, which makes it necessary to improve its chemical composition and mechanical properties, reduce its thickness and weight, expand the range of new types of steel strip and increase its production. This entails a large number of technological operations dependent on precise temperature measurement and control. In some industrial plants, the steel strip is in continuous motion, which makes the use of contact measuring devices impossible.
View Article and Find Full Text PDFRev Sci Instrum
April 2024
Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22904, USA.
Gas turbine engines subject materials to extreme conditions. Their high temperature materials and co-developed coatings must survive combustion gas temperatures currently approaching 1800 °C, large thermal gradients, severe thermal shock, and static and fatigue inducing applied stresses, all the while operating in highly reactive, high-pressure, high-speed combustion gas flows containing significant partial pressures of water vapor, oxygen, and other reactive species for many tens of thousands of hours. We describe the design and development of a test facility for the study of materials under individual and combinations of test parameters similar to those experienced within legacy and future engines.
View Article and Find Full Text PDFThe multispectral radiometric temperature measurement technique is affected by the unknown emissivity, and there is no multispectral radiometric temperature inversion algorithm applicable to any scene or target. To address the above problems, this paper converts the multispectral radiometric temperature inversion problem into an image recognition problem containing the temperature information to be measured, and proposes a graphical multispectral radiometric temperature adaptive inversion algorithm. In this paper, we use the difference between spectral channels to convert the one-dimensional radiation data into a two-dimensional radiation map; use the generalized inverse to obtain the spectral emissivity distribution features, fuse them with the two-dimensional radiation map, and use an improved deep learning network to achieve adaptive temperature inversion.
View Article and Find Full Text PDFData Brief
December 2023
Department of Industrial and Systems Engineering, Mississippi State University, Mississippi State, MS 39762, United States.
In-process thermal melt pool images and post-fabrication porosity labels are acquired for Ti-6Al-4V thin-walled structure fabricated with OPTOMEC Laser Engineered Net Shaping (LENS™) 750 system. The data is collected for nondestructive thermal characterization of direct laser deposition (DLD) build. More specifically, a Stratonics dual-wavelength pyrometer captures a top-down view of the melt pool of the deposition heat-affected zone (HAZ), which is above , and Nikon X-Ray Computed Tomography (XCT) XT H225 captures internal porosity reflective of lack of fusion during the fabrication process.
View Article and Find Full Text PDFSensors (Basel)
May 2023
Institute of Photonic Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg, Konrad-Zuse-Str. 3/5, 91052 Erlangen, Germany.
Spatial and temporal knowledge of temperature evolution is crucial in laser beam welding of low-melting materials such as aluminum alloys. Current temperature measurements are restricted to (i) one-dimensional temperature information (e.g.
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