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One-sided infrared thermal imaging for flaw characterization of ceramic matrix composites

Description: One-sided infrared thermal imaging is being used to characterize voids and delamination in SiC/SiC composites. Flaw depth is estimated by examining the decay of surface temperature after application of a thermal pulse. Digital analysis of the surface temperature/time relationship allows characterization of the sizes and positions of defects. Results show that defects of various sizes and depths can be characterized in SiC/SiC composites with the technique.
Date: May 16, 2000
Creator: Deemer, C.; Sun, J. G. & Ellingson, W. A.
Partner: UNT Libraries Government Documents Department
open access

Issues associated with the use of infrared thermography for experimental testing of insulated systems

Description: Infrared scanning radiometers are used to generate temperature maps of building envelope components (windows, insulation), which may assist in evaluating their thermal performance. Accuracy of an IR scanner for laboratory-based surface temperature measurements was evaluated and details for achieving max accuracy identified. Minimum uncertainty in IR temperature measurement is {+-}0.5 C. Using an external reference emitter to scale the absolute value of IR scanner temperature measurements can im… more
Date: December 1, 1995
Creator: Griffith, B.; Beck, F.; Arasteh, D. & Tuerler, D.
Partner: UNT Libraries Government Documents Department
open access

Thermal Imaging Control of Furnaces and Combustors

Description: The object if this project is to demonstrate and bring to commercial readiness a near-infrared thermal imaging control system for high temperature furnaces and combustors. The thermal imaging control system, including hardware, signal processing, and control software, is designed to be rugged, self-calibrating, easy to install, and relatively transparent to the furnace operator.
Date: February 28, 2003
Creator: Rue, David M.; Zelepouga, Serguei & Puri, Ishwar K.
Partner: UNT Libraries Government Documents Department
open access

Statistics for the Relative Detectability of Chemicals in Weak Gaseous Plumes in LWIR Hyperspectral Imagery

Description: The detection and identification of weak gaseous plumes using thermal imaging data is complicated by many factors. These include variability due to atmosphere, ground and plume temperature, and background clutter. This paper presents an analysis of one formulation of the physics-based model that describes the at-sensor observed radiance. The motivating question for the analyses performed in this paper is as follows. Given a set of backgrounds, is there a way to predict the background over which… more
Date: October 30, 2008
Creator: Metoyer, Candace N.; Walsh, Stephen J.; Tardiff, Mark F. & Chilton, Lawrence
Partner: UNT Libraries Government Documents Department
open access

Measurement of directional thermal infrared emissivity of vegetation and soils

Description: A new method has been developed for measuring directional thermal emissivity as a function of view angle for plant canopies and soils using two infrared thermometers each sensitive to a different wavelength band. By calibrating the two infrared thermometers to 0.1C consistency, canopy directional emissivity can be estimated with typical errors less than 0.005 in the 8--14 um wavelength band, depending on clarity of the sky and corrections for CO{sub 2} absorption by the atmosphere. A theoretica… more
Date: October 1, 1995
Creator: Norman, J.M. & Balick, L.K.
Partner: UNT Libraries Government Documents Department
open access

Design Considerations, Modeling and Analysis for the Multispectral Thermal Imager

Description: The design of remote sensing systems is driven by the need to provide cost-effective, substantive answers to questions posed by our customers. This is especially important for space-based systems, which tend to be expensive, and which generally cannot be changed after they are launched. We report here on the approach we employed in developing the desired attributes of a satellite mission, namely the Multispectral Thermal Imager. After an initial scoping study, we applied a procedure which we ca… more
Date: February 1, 1999
Creator: Borel, C. C.; Clodius, W. B.; Cooke, B. J.; Smith, B. W. & Weber, P. G.
Partner: UNT Libraries Government Documents Department
open access

APPLICATIONS OF IR THERMOGRAPHY IN CAPTURING THERMAL TRANSIENTS AND OTHER HIGH SPEED THERMAL EVENT

Description: The high-speed, snap-shot mode, and the external triggering capability of an IR camera allows thermal transients to be captured. These advanced features were used to capture thermal transients during electrical breakdown of ZnO varistors and to freeze the rotation of an automobile disk brake in order to study thermoplastic instability in the braking system. The IR camera also showed the thermoplastic effect during cyclic fatigue testing of a glass matrix composite.
Date: June 7, 1999
Creator: Wang, H.; Dinwiddie, R. B. & Graham, S.
Partner: UNT Libraries Government Documents Department
open access

Delamination detection in reinforced concrete using thermal inertia

Description: We investigated the feasibility of thermal inertia mapping for bridge deck inspections. Using pulsed thermal imaging, we heat-stimulated surrogate delaminations in reinforced concrete and asphalt-concrete slabs. Using a dual-band infrared camera system, we measured thermal inertia responses of Styrofoam implants under 5 cm of asphalt, 5 cm of concrete, and 10 cm of asphalt and concrete. We compared thermal maps from solar-heated concrete and asphalt-concrete slabs with thermal inertia maps from… more
Date: November 30, 1998
Creator: Del Grande, N K & Durbin, P F
Partner: UNT Libraries Government Documents Department
open access

Thermal diffusivity mapping of 4D carbon-carbon composites

Description: High resolution, 2-D thermal diffusivity maps of carbon-carbon composites were obtained by a state-of-the-art infrared thermal imaging system. Unlike the traditional single-point IR detector used for thermal diffusivity measurements, the IR camera is capable of capturing images in its 256 x 256 pixel Focal Plane Array detector in a snap-shot mode. The camera takes up to 200 images at a rate of 120 frames/second. The temperature resolution of the Ir camera is 0.015 C and the spatial resolution i… more
Date: March 1997
Creator: Wang, H. & Dinwiddie, R. B.
Partner: UNT Libraries Government Documents Department
open access

Effective Conveyor Belt Inspection for Improved Mining Productivity Semi-Annual Technical Progress Report: November 2004 - May 2005

Description: This document details progress on the project entitled ''Effective Conveyor Belt Inspection for Improved Mining Productivity'' during the period from November 15, 2004 to May 14, 2004. Highlights include fabrication of low-cost prototype hardware, acquisition of infrared thermal data, and initial design of a Smart-Camera based system.
Date: June 1, 2006
Creator: Fromme, Chris
Partner: UNT Libraries Government Documents Department
open access

Burn Depth Estimation Based on Infrared Imaging of Thermally Excited Tissue

Description: Accurate estimation of the depth of partial-thickness burns and the early prediction of a need for surgical intervention are difficult. A non-invasive technique utilizing the difference in thermal relaxation time between burned and normal skin may be useful in this regard. In practice, a thermal camera would record the skin's response to heating or cooling by a small amount-roughly 5 C for a short duration. The thermal stimulus would be provided by a heat lamp, hot or cold air, or other means. … more
Date: March 5, 1999
Creator: Dickey, F.M.; Hoswade, S.C. & Yee, M.L.
Partner: UNT Libraries Government Documents Department
open access

Surface temperatures of insulated glazing units: Infrared thermography laboratory measurements

Description: Data are presented for the distribution of surface temperatures on the warm-side surface of seven different insulated glazing units. Surface temperatures are measured using infrared thermography and an external referencing technique. This technique allows detailed mapping of surface temperatures that is non-intrusive. The glazings were placed between warm and cold environmental chambers that were operated at conditions corresponding to standard design conditions for winter heating. The temperat… more
Date: December 1, 1995
Creator: Griffith, B.T.; Tuerler, D. & Arasteh, D.
Partner: UNT Libraries Government Documents Department
open access

Emerging NDE Technology for aging aircraft

Description: This paper presents an overview of several emerging nondestructive evaluation technologies that are being employed or considered for use to inspect commercial transport, commuter aircraft and military aircraft. An overview of the Federal Aviation Administration (FAA) Airworthiness Assurance NDI Validation Center (AANC) is described and how AANC teams with industry, universities, and other federal entities to assess these technologies.
Date: March 1, 1998
Creator: Moore, David G. & Perry, Richard L.
Partner: UNT Libraries Government Documents Department
open access

Multi-angle technique for measurement of ground source emission

Description: TAISIR, the Temperature and Imaging System Infrared, is a nominally satellite based platform for remote sensing of the earth. One of its design features is to acquire atmospheric data simultaneous with ground data, resulting in minimal dependence on external atmospheric models for data correction. One technique we employ to acquire atmospheric data is a true multi-angle data acquisition technique. Previous techniques have used only two angles. Here we demonstrate the advantage of using a large … more
Date: April 1, 1995
Creator: Henderson, J. R.
Partner: UNT Libraries Government Documents Department
open access

Thermal imaging measurement of lateral thermal diffusivity in continuous fiber ceramic composites

Description: Infrared thermal imaging has become a common technique for nondestructive evaluation and measurement of thermal properties in ceramic specimens. Flash thermal imaging can be used to determine two-dimensional through-thickness thermal diffusivity in a planar specimen. In this study, the authors extended the method to determine lateral, or transverse, thermal diffusivity in the specimen. During the flash thermal imaging test, pulsed heat energy is applied to a specimen's back surface, which is pa… more
Date: February 18, 2000
Creator: Sun, J. G.; Deemer, C. & Ellingson, W. A.
Partner: UNT Libraries Government Documents Department
open access

Infrared Thermometer (IRT) Handbook

Description: The Infrared Thermometer (IRT) is a ground-based radiation pyrometer that provides measurements of the equivalent blackbody brightness temperature of the scene in its field of view. The downwelling version has a narrow field of view for measuring sky temperature and for detecting clouds. The upwelling version has a wide field of view for measuring the narrowband radiating temperature of the ground surface.
Date: October 30, 2006
Creator: Morris, VR
Partner: UNT Libraries Government Documents Department
open access

Nonlinear Bayesian Algorithms for Gas Plume Detection and Estimation from Hyper-spectral Thermal Image Data

Description: This paper presents a nonlinear Bayesian regression algorithm for the purpose of detecting and estimating gas plume content from hyper-spectral data. Remote sensing data, by its very nature, is collected under less controlled conditions than laboratory data. As a result, the physics-based model that is used to describe the relationship between the observed remotesensing spectra, and the terrestrial (or atmospheric) parameters that we desire to estimate, is typically littered with many unknown "… more
Date: June 13, 2007
Creator: Heasler, Patrick G.; Posse, Christian; Hylden, Jeff L. & Anderson, Kevin K.
Partner: UNT Libraries Government Documents Department
open access

Dynamic thermal tomography for nondestructive inspection of aging aircraft

Description: The authors apply dual-band infrared (DBIR) imaging as a dynamic thermal tomography tool for wide area inspection of a Boeing 737 aircraft and several Boeing KC-135 aircraft panels. The analyses are discussed in this report. After flash-heating the aircraft skin, they record synchronized DBIR images every 40 ms, from onset to 8 seconds after the heat flash. They analyze selective DBIR image ratios which enhance surface temperature contrast and remove surface-emissivity clutter. The Boeing 737 a… more
Date: November 1, 1993
Creator: Del Grande, N. K.; Dolan, K. W.; Durbin, P. F.; Gorvad, M. R. & Shapiro, A. B.
Partner: UNT Libraries Government Documents Department
open access

Demonstration of dual-band infrared thermal imaging at Grass Valley Creek bridges

Description: We demonstrated dual-band infrared (DBIR) thermal imaging at the Grass Valley Creek Bridges near Redding CA. DBIR thermal imaging is an enabling technology for rapid, reliable, bridge deck inspections while minimizing lane closures. bridge-deck inspections were conducted from a mobile DBIR bridge inspection laboratory during November 2-3, 1995. We drove this self-contained unit at limited highway speeds over 0.4 lane miles of bridge deck. Using two thermal IR bands, we distinguished delaminatio… more
Date: November 1, 1996
Creator: Del Grande, N. K.; Durbin, P. F.; Logan, C. M.; Perkins, D. E. & Schich, P. C.
Partner: UNT Libraries Government Documents Department
open access

Multi-use applications of dual-band infrared (DBIR) thermal imaging for detecting obscured structural defects

Description: Precise dual-band infrared (DBIR) thermal imaging provides a useful diagnostic tool for wide-area detection of defects from corrosion damage in metal airframes, heat damage in composite structures and structural damage in concrete bridge decks. We use DBIR image ratios to enhance surface temperature contrast, remove surface emissivity noise and increase signal-to-clutter ratios. We clarify interpretation of hidden defect sites by distinguishing temperature differences at defect sites from emiss… more
Date: May 1, 1994
Creator: Del Grande, N. K. & Durbin, P. F.
Partner: UNT Libraries Government Documents Department
open access

Using Infrared Thermography for the Creation of a Window Surface Temperature Database to Validate Computer Heat Transfer Models

Description: IR thermography is well suited for resolving small differences in the thermal performance of highly insulating window systems. Infrared thermographic measurements made in conjunction with reference emitter techniques in a controlled and characterized laboratory setting can have an absolute accuracy of {plus_minus}0.5{degree}C. Quantitative infrared thermography requires that a number of sources of error related to measurement accuracy and test environmental conditions be quantified and minimize… more
Date: April 1, 1995
Creator: Beck, F. A.; Griffith, B. T.; Tuerler, D. & Arasteh, D.
Partner: UNT Libraries Government Documents Department
open access

Dual-band infrared capabilities for imaging buried object sites

Description: We discuss dual-band infrared (DBIR) capabilities for imaging buried object sizes. We identify physical features affecting thermal contrast needed to distinguish buried object sites from undisturbed sites or surface clutter. Apart from atmospheric transmission and system performance, these features include: object size, shape, and burial depth; ambient soil, disturbed soil and object site thermal diffusivity differences; surface temperature, emissivity, plant-cover, slope, albedo and roughness … more
Date: April 2, 1993
Creator: Del Grande, N. K.; Durbin, P. F.; Gorvad, M. R.; Perkins, D. E.; Clark, G. A.; Hernandez, J. E. et al.
Partner: UNT Libraries Government Documents Department
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