Application Of Infrared Thermography Research Articles

Infrared Thermography application to functional and failure analysis of electron devices and circuits

In this paper the principal and more important application of Infrared Thermography are discussed. In particular the application of this experimental technique, both in its transient and steady-state mode of operation, are reported and illustrated through a broad set of experiments and examples. Functional application to the characterization of VLSI devices, application to the failure analysis of large area power devices, current monitoring in state-of-art heterojunction and organic devices prove the high potential of this technique.

Thermal Imaging of Aye-Ayes (Daubentonia madagascariensis) Reveals a Dynamic Vascular Supply During Haptic Sensation

Infrared thermography (IRT) is used to visualize and estimate variation in surface temperatures. Applications of IRT to animal research include studies of thermofunctional anatomy, ecology, and social behavior. IRT is especially amenable to investigations of the somatosensory system because touch receptors are highly vascularized, dynamic, and located near the surface of the skin. The hands of aye-ayes (Daubentonia madagascariensis) are thus an inviting subject for IRT because of the prominent middle digit that functions as a specialized haptic sense structure during percussive and probative foraging. It is a vital sensory tool that is expected to feature a high density of dermal mechanoreceptors that radiate heat and impose thermal costs under cool temperatures. Here we explore this premise by acquiring IRT images of 8 aye-ayes engaged in a variety of passive and probative behaviors. We found that the middle digit was typically 2.3°C cooler than other digits when the metacarpophalangeal (MP) joint was extended, and that it warmed an average of 2.0°C when the MP joint was flexed during active touching behavior. These changes in digital surface temperature, which were sometimes as much 6.0°C, stand in sharp contrast with the profoundly invariant temperatures of the other digits. Although the physiological mechanisms behind these temperature changes are unknown, they appear to reveal a uniquely dynamic vascular supply.

Active infrared thermography applied to defect detection and characterization on asphalt pavement samples: comparison between experiments and numerical simulations

This work is devoted to the application of active infrared thermography to defect detection in pavement structures. The challenge is to localize and to determine some properties of defects (e.g. shape and depth) into a highly heterogeneous material. Experimental work was carried out in laboratory conditions using a pavement sample containing two defects (wood and air). Pulsed thermography results were compared with FLUENT numerical simulations. Different preliminary approaches were investigated to analyze data: singular value decomposition of infrared image sequences, contrast image methods and computation of thermal effusivity considering a heat transfer model in a semi-infinite material. This last method is more sensitive to experimental conditions such as the presence of natural convection at a sample surface. However, all methods allow detection of one defect into the pavement sample.

On the determination of residual feed intake and associations of infrared thermography with efficiency and ultrasound traits in beef bulls

To determine the relationship of infrared thermography (IR) and ultrasound measures (US) with the variation in feed efficiency and daily dry matter intake (DMI), alternative models for calculating residual feed intake (RFI) were tested using DMI, average daily gain (ADG), mid-trial body weight (BW), body surface temperature measured using IR, and mid-trial US (ribeye area, backfat thickness and marbling score) from 154 crossbred bulls. The original model (Koch's model) for RFI (RFI koch), based on a regression of DMI on BW and ADG had the lowest coefficient of determination ( R 2; 0.58) and was included as the base model in all the other alternate extended models tested. The residual or error term from the model represents the calculated RFI. RFI calculated including ribeye area (RFI rbea) had the highest R 2 (0.62) of all US at mid-trial. RFI including all US traits (RFI usdt) had the same R 2 (0.63) but higher, less desirable, Bayesian information criterion (BIC; 456.2 vs. 334.9) than the model where only feet temperature was added to Koch's model. A model combining mid-trial US and feet IR (RFI usir) had the greatest R 2 (0.67) and BIC (327.7). RFI koch was correlated with eye, cheek and feet temperature (0.24 to 0.43) but not with ribs, rear area or scrotum temperature. Bulls were also sorted into RFI koch groups (high, medium, low). Eye, cheek and feet had lower temperature in low-RFI bulls compared to high-RFI bulls (less efficient). The feed to gain ratio (F:G) and DMI was higher for high-RFI than for low-RFI bulls. Further analysis demonstrated that 28% of the RFI koch variation was explained by US (4%) and IR (24%), where feet and cheek were the major IR traits, representing 74% of the IR contribution to the explained variation in RFI koch. Our results provide evidence that: (1) Koch's model might be improved by adding US traits; (2) US and IR traits are useful to explain the DMI variation; (3) IR of different body locations have distinct relationships with RFI (RFI kock and RFI usdt), and with other efficiency traits and US; and (4) heat production (IR) explains a greater proportion of the variation in RFI than body composition (US). This study demonstrates the potential for improving RFI determination and also the application of IR in the assessment of feed efficiency. Further studies to develop standard procedures for performing infrared imaging might increase the predictability of this technology for assessing feed efficiency, especially residual feed intake, in cattle.

Thermographic Evaluation for the Efficacy of Acupuncture on Induced Chronic Arthritis in the Dog

This study was performed to evaluate the efficacy of acupuncture on induced chronic arthritis of the dog by thermography. Complete Freund's adjuvant was injected into the left knee joint of 8 dogs to induce arthritis. Acupuncture was applied to BL-40, GB-33, GB-34, and LIV-8 once a week for 4 consecutive weeks, from 3 weeks after induction of chronic arthritis, in treatment group. At 3 weeks of acupuncture treatment, skin temperature difference (DeltaT) of treatment group returned to normal range (< 0.3 degrees C), while DeltaT remained high in non-treatment group. Infrared thermography (IRT) is useful to evaluate the treatment of acupuncture for induced canine chronic arthritis. Therefore, it is considered that clinical application of IRT in arthritis treatment would be also valuable.

Installation and application of ultrasonic infrared thermography

Installation and application of ultrasonic infrared thermography

An overview of infrared thermography techniques used in large wind tunnels

Infrared thermography (IRT) is used at Onera in large facilities for boundary layer visualization and for heat flux assessment. Modern IR cameras and insulating paints enable efficient visualization of the laminar/turbulent transition region. This technique is now applied in large transonic test facilities. Heat flux assessment is one of the main purposes of hypersonic tests. It is done mainly with IRT and dedicated softwares, while sensors as thermocouples are used to check the reliability of IRT. A 1D data reduction method has been developed to provide the heat flux through temperature measurements. It takes into account thickness and curvature effects. The method has been recently improved to be used with steel models covered with an insulating paint, which provides a high emissivity. The temperature film is converted into a heat flux film, which is be used to extract the useful information. This requires image processing tools that relate every pixel to a point on the model. A new application of IRT is going on in the Onera's high enthalpy hypersonic wind tunnel F4. The camera is used in single-line scan mode because of the short duration of the run. The main difficulty comes from the flow, which is not transparent. The first trial to cope with this kind of optical pollution is encouraging.

Thermomechanical effects accompanying the localized necking of semi-crystalline polymers

This paper presents an application of quantitative infrared thermography to the analysis of the mechanical behavior of materials. We particularly focus on the thermomechanical behavior of a semi-crystalline polymer below its glass transition temperature. During a quasi-static tensile test, the temperature distribution at the surface of a thin flat sample is recorded by an infrared camera. Using a local expression of the heat balance, the distribution of heat sources is derived from thermal measurements. These calorimetric data are then correlated with strain and stress fields. Indeed, a second optical device gives displacement fields using correlation methods on speckle images. Strain and strain-rate are derived from displacement data by numerical differentiation. The load-displacement curve shows three stages: first the load increases with the stretching, then a significant softening of the sample occurs until it flows at constant load. Both calorimetric and kinematic measurements indicate that the sample softening is associated with a progressive localization of heat sources and strain-rates, while the loading plateau corresponds with a regular expansion of the neck. A local construction of stress-strain diagram is then proposed. Several stress-strain curves are finally analyzed taking into account the loading stage characteristics and the expansion mode of the necking region.

Active zone self-similarity of fractal-Sierpinski antenna verified using infra-red thermograms

The surface current distribution of a Sierpinski fractal antenna shows a self-similar behaviour determined by the self-similar properties of its geometry. The application of infra-red thermography to electromagnetic near field detection allows the experimental verification of the active region scaling of a fractal antenna operating at different bands.

The application of IR thermography to process monitoring and control of reflow soldering

This paper describes a technique for the monitoring and control of the reflow soldering process. The technique combines state‐of‐the‐art infra‐red (IR) sensor technology, coupled with application‐specific process monitoring and control software, providing a unique capability both to monitor product temperatures during processing and to modify the process settings. The development of techniques to allow variation of the heat transfer from the oven to the in‐process printed circuit assemblies (PCAs) provides the means to adjust the soldering oven’s process settings for each individual PCA. This automatic profiling ensures consistent thermal histories and optimises oven energy consumption. Archiving of the reflow profiles along with temperatures recorded for each PCA provides full traceability to the reflow process settings for each individual PCA. The incorporation of IR sensing technology also provides a means to monitor the performance of the process.

The application of thermal infrared thermography in the identification of submerged springs in Chickamauga Reservoir, Hamilton County, Tennessee : Bogle, F.R.; Loy, K. Proceedings of the 5th Multidisciplinary Conference on Sinkholes and the Engineering and Environmental Impacts of Karst, Gatlinburg, Tennessee (United States), 2–5 Apr. 1995, pp. 415–424. Edited by B.F. Beck. A.A. Balkema (1995) ISBN 9054105356

The application of thermal infrared thermography in the identification of submerged springs in Chickamauga Reservoir, Hamilton County, Tennessee : Bogle, F.R.; Loy, K. Proceedings of the 5th Multidisciplinary Conference on Sinkholes and the Engineering and Environmental Impacts of Karst, Gatlinburg, Tennessee (United States), 2–5 Apr. 1995, pp. 415–424. Edited by B.F. Beck. A.A. Balkema (1995) ISBN 9054105356

The application of thermal infrared thermography in the identification of submerged springs in Chickamaug Reservoir, Hamilton County, Tennessee : F. R. Bogle & K. Loy, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 415–424

The application of thermal infrared thermography in the identification of submerged springs in Chickamaug Reservoir, Hamilton County, Tennessee : F. R. Bogle & K. Loy, in: Karst geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 415–424

Time-resolved derivation of heat fluxes from quantitative infrared thermography and its relationship to photoacoustics

Part of the plasma power losses in magnetic-confinement-based nuclear-fusion devices is deposited on limiters or divertor targets. This part can be deduced quantitatively from time- and space-resolved infrared (IR) surface-temperature measurements at the limiter or divertor targets by solving the heat-conduction equation of the target plate with the help of inversion solutions for the incident heat flux. This quantitative application of IR thermography and photoacoustic or photothermal frequency-dependent measurements are related, complementary techniques. Photoacoustics provides the means to measure the relevant thermal properties, i.e., the value of the effusivity (kρc)1/2 of the target plate, necessary for the quantitative interpretation of the thermographical measurements.

Application of Infra-Red Thermography to the Study of Temperature Distribution on Energized Polluted Insulators

Temperature distribution on the surface of an energized polluted insulator has been measured using infra-red hermo thermovision techniques. Temporal variation of temperature has also been determined. Tests were carried out on a conventional ional cap and pin insulator unit. Results show that the maximum temperature of the energized insulator could be as high as 100°C at the regions around the pin.

Infra-red thermography in hand surgery

A short description has been given of the use of infra-red thermography with regard to the hands. Investigations on this subject have shown that thermographic examination is a useful complementary help to the general methods of examination—but does not replace them. The application of infra-red thermography is of practical value especially in rheumatoid arthritis. In the diagnosis of inflammatory processes and in recording the behaviour following treatment thermography is of value, furthermore post-operative examinations register the results of surgery and may indicate recurrence.

Application of Infra-Red Thermography in the Paper Industry

A brief study has been carried out into the possible applications of real-time infra-red thermal imaging devices in the paper and board industry. Because of lack of experience the interpretation of the displays produced by the devices can be difficult. It appears that under some circumstances the instruments can be used to study non-uniformity problems and though the presence of these can be demonstrated, the data available as yet does not allow detailed diagnosis by employing IR thermal images.