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The Inspection of CFRP Laminate with Subsurface Defects by Laser Arrays Scanning Thermography (LAsST)
摘要： Laser array scanning thermography (LAsST) was used to detect the subsurface defects of carbon fiber reinforced composite (CFRP). A series of bottom flat hole (BFHs) of CFRP were prepared for LAsST. Truncation pseudo-static matrix reconstruction (TC-PSMR) method was used to reconstruct the thermal response signal. Fast Fourier transform (FFT), principal component analysis (PCA) and partial least squares regression (PLSR) were used to process the thermal response signals, forming FFT image, PCA image, and PLSR image. The signal noise ratios (SNRs) of defects is calculated, and it is used to evaluate the defect detection ability of different post-processing algorithms. The experimental results show that the image based on FFT phase has a higher signal-to-noise ratio with PLSR image, and the FFT amplitude image and PLSR image can accurately represent the defect size.
关键词： FFT,Laser arrays scan thermography,Partial least squares regression,CFRP
更新于2025-09-23 15:19:57
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Comparison of two skin temperature assessment methods after the application of topical revulsive products: Conductive iButton data logger system vs contact-free infrared thermometry
摘要： Background: Skin temperature assessments comprise conductive and contact-free techniques. Comparison between conductive data loggers and contact-free thermometry after the application of revulsive products is scarce. This study aimed to compare iButton data loggers with an infrared thermometer after the application of two revulsive products. Secondly, the relation between skin temperature kinetics with skin's perfusion of microcirculation was investigated. Materials and methods: Healthy females (n = 25) were randomly allocated to two groups, representing the products A and B. Skin temperature was measured with “iButtons” and an infrared pistol at baseline and up to 1 hour after application. Skin's perfusion of microcirculation was monitored with a laser speckle contrast imager. Results: Baseline “iButton” temperature values were significantly lower compared with infrared pistol values in both groups. After application of the products, skin temperature decreased as recorded with both devices followed by an increase to baseline values when measured with the pistol. The results obtained by the “iButtons” reached values above baseline in both products towards the end of the follow-up period. A moderate correlation was found between infrared pistol and “iButton” system in product A, with a weak negative correlation between skin's perfusion of microcirculation and temperature devices. For product B, the correlation between the devices was moderate and between skin's perfusion and temperature devices weak and positive. Conclusion: Both devices produced similar kinetics, except at baseline, where they may differ as metallic loggers have been insufficiently adapted to skin temperature. Skin's perfusion of microcirculation could not explain skin temperature changes.
关键词： thermocouples,laser speckle contrast imaging,infrared thermography,skin temperature,revulsive products
更新于2025-09-23 15:19:57
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Thermal Imaging of Flame in Air-assisted Atomizer for Burner System
摘要： Infrared thermography was used as a part of non-intrusion technique on the flame temperature analysis. This paper demonstrates the technique to generate the thermal images of flame from the air-assisted atomizer. The multi-circular jet plate acts as a turbulence generator to improve the fuel and air mixing in the atomizer. Three types of multi-circular jet plate geometry were analysed at different equivalence ratio. Thermal infrared imaging using FLIR thermal camera were used to obtain the flame temperature. Multi-circular jet 1 shows the highest flame temperature obtained compared to other plates. It can be concluded that the geometry of the plate influences the combustion, hence affects the flame temperature profile from the air-assisted atomizer.
关键词： flame temperature,multi-circular jet plate,Infrared thermography,air-assisted atomizer,equivalence ratio
更新于2025-09-23 15:19:57
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Condition Monitoring of Wind Turbine Blades Using Active and Passive Thermography
摘要： The failure of wind turbine blades is a major concern in the wind power industry due to the resulting high cost. It is, therefore, crucial to develop methods to monitor the integrity of wind turbine blades. Different methods are available to detect subsurface damage but most require close proximity between the sensor and the blade. Thermography, as a non-contact method, may avoid this problem. Both passive and active pulsed and step heating and cooling thermography techniques were investigated for different purposes. A section of a severely damaged blade and a small “plate” cut from the undamaged laminate section of the blade with holes of varying diameter and depth drilled from the rear to provide “known” defects were monitored. The raw thermal images captured by both active and passive thermography demonstrated that image processing was required to improve the quality of the thermal data. Different image processing algorithms were used to increase the thermal contrasts of subsurface defects in thermal images obtained by active thermography. A method called “Step Phase and Amplitude Thermography”, which applies a transform-based algorithm to step heating and cooling data was used. This method was also applied, for the ?rst time, to the passive thermography results. The outcomes of the image processing on both active and passive thermography indicated that the techniques employed could considerably increase the quality of the images and the visibility of internal defects. The signal-to-noise ratio of raw and processed images was calculated to quantitatively show that image processing methods considerably improve the ratios.
关键词： wind turbine blades,defects,thermography,image processing,condition monitoring
更新于2025-09-19 17:15:36
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - An Experiment of Geothermal Exploration with an Uas-Tir in Xiaoyoukeng Area of Tatun Volcanoes, Taiwan
摘要： Geothermal exploration requires thermal images for obtaining the temperature on ground surface for characterizing surface geology and modeling the temperature at the depth. The purpose of this study is to integrate a thermal sensor with a wind-resistant UAV for detecting geothermal anomalies suitable for conducting exploration in a mountainous terrain. The specifications of the UAS-TIR, the experiment at XiaoYoukeng, and the results are presented. It is proved that such a system can be effectively applied in assisting quantitative assessment of geothermal reserves when compared with airborne thermal systems.
关键词： remote sensing,green energy,thermography,hyperspectral imaging
更新于2025-09-19 17:15:36
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[ASME ASME 2018 International Mechanical Engineering Congress and Exposition - Pittsburgh, Pennsylvania, USA (Friday 9 November 2018)] Volume 8A: Heat Transfer and Thermal Engineering - Infrared Thermography to Measure Heat Transfer of a Heated Curved Thin Sheet
摘要： Heat transfer measurements on a heated curved thin sheet are performed by infrared thermography. The evolution of the temperature field is recorded to calculate the heat flux by using the two-dimensional unsteady heat balance equation. The thermal conduction term is estimated by the projection relationship between the curved surface of the thin sheet and the horizontal plane. Natural convection is neglected during the estimation of this heat flux. Unlike the traditional means of heat flux measurement, this method is non-intrusive and can measure the heat flux distribution within a curved space, allowing an easier evaluation of the errors due to radiation and tangential conduction. An electrical resistance foil with known power are applied as the heating source to compare the calculated heating power with the actual recorded power, the max relative error for different heating powers is about 10 %, which verified of the feasibility of the method. Considering possible applications, three different domestic gas cookers are used to heat three different curved thin pans, and then, in each case, the heat flux of the burners is analyzed. From the heat flux distribution of the three gas cookers, some heating characteristics such as heating power, maximum and average heating flux are investigated to help optimize the designs of the gas cookers, avoiding local over-heating and low uniformity of heat distribution.
关键词： Heat transfer measurements,infrared thermography,heating characteristics,gas cookers,curved thin-sheet
更新于2025-09-19 17:15:36
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[IEEE 2018 IEEE XXVII International Scientific Conference Electronics (ET) - Sozopol (2018.9.13-2018.9.15)] 2018 IEEE XXVII International Scientific Conference Electronics - ET - Improving control of excitation sources in transient and lock-in thermography
摘要： The aim of the paper is to study the possibilities for using one excitation source for transient as well as lock-in infrared thermography modes. Problems in controlling the high-power optical excitation sources in active thermography are analysed. Special attention is paid to high power LEDs as sources for thermal stimulation in thermography. A method for improving control of high-power optical and electrical types of excitation sources is proposed with possibility of voltage or current stabilization.
关键词： active thermography,excitation source,current sensing,multiphase DC/DC converter,power LED
更新于2025-09-19 17:15:36
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[IEEE 2018 IEEE International Symposium on the Physical and Failure Analysis of Integrated Circuits (IPFA) - Singapore (2018.7.16-2018.7.19)] 2018 IEEE International Symposium on the Physical and Failure Analysis of Integrated Circuits (IPFA) - Improved Phase Data Acquisition for Thermal Emissions Analysis
摘要： This paper describes a 2X improvement in phase data acquisition for Lock-in Thermography (LIT). Phase data is used to generate phase shift versus applied lock-in frequency plots to estimate defect depth in semiconductor packages. Typically, samples need to be tested for an extended time to ensure data consistency. Furthermore, determining the specific point on the thermal emission site to collect data from can be challenging, especially if it is large and dispersive. To overcome these difficulties, new computational algorithms along with streamlined and automated workflows, such as self-adjusting site positioning and phase measurement auto-stop, are employed to validate improvements to data repeatability and accuracy as well as faster time to results on different advanced packaging devices such as flip chips and stack dies. Overall, our results showed a 2X faster time to more accurate and repeatable data for X, Y, and Z depth localization.
关键词： Z depth localization,Lock-in thermography
更新于2025-09-19 17:15:36
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[IEEE 2018 IEEE International Symposium on the Physical and Failure Analysis of Integrated Circuits (IPFA) - Singapore (2018.7.16-2018.7.19)] 2018 IEEE International Symposium on the Physical and Failure Analysis of Integrated Circuits (IPFA) - 3D Defect Localization of Stacked Die Devices by Lock-in Thermography (LIT)
摘要： The article reports three real cases using lock-in thermography (LIT) for the fault isolation of multi stacked die devices, for which it is challenging to localize the defect position before destructive analysis since the structure is complicated. By measurement of the phase shift value, the defect depth can be successfully localized. Physical failure analysis was performed on all three cases and the results match the LIT fault isolation result.
关键词： stacked die,lock-in thermography
更新于2025-09-19 17:15:36
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Application of infrared thermography in diagnosing peripherally inserted central venous catheter infections in children with cancer
摘要： Children affected by oncological diseases are often fitted with central venous catheters. Catheter infection is a frequent complication, sometimes accompanied by thrombosis. It is designed a case/control-type pilot study of children with oncological diseases fitted with a central venous catheter. The objective of this preliminary study is to use infrared thermography to discern whether there is an infection in patients with a central venous catheter and if so, to undertake a close follow-up of its evolution, after administering a therapy. It is measured Thermal Asymmetry by mean and maximum temperatures (Temperature affected ROI – Temperature contralateral ROI). In all cases with catheter infection, Thermal Asymmetry values were higher than in controls without infection, allowing us to assess improvement after starting the treatment. These preliminary results are satisfactory because they reflect the advantages of using infrared thermography on oncological child patients, as it is a harmless, non-contact, accessible and quick technique, allowing us to reduce the use of ionizing radiation and quantify the clinical signs of inflammation, which are otherwise only qualitatively detectable in the clinical examination. By doing so, it may be possible to anticipate infection and provide early treatment, and, moreover, to observe whether there is any complication after starting a treatment. More studies need to be undertaken with an extensive paediatric population to establish reference values.
关键词： infrared thermography,central venous catheter infection,cancer,children
更新于2025-09-19 17:15:36